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NASA & NOAA: April 2014 Warmest Globally On Record

According to data released by NASA and NOAA this month, April was the warmest April globally on record.  Here are the data for NASA’s analysis; here are NOAA data and report.  The two agencies have different analysis techniques, which in this case resulted in slightly different temperature anomaly values but the same overall rankings within their respective data sets.  The analyses result in different rankings in most months.  The two techniques do provide a check on one another and confidence for us that their results are robust.  At the beginning, I will remind readers that the month-to-month and year-to-year values and rankings matter less than the long-term climatic warming.  Weather is the dominant factor for monthly and yearly conditions, not climate.

The details:

April’s global average temperature was 0.73°C (1.314°F) above normal (14°C; 1951-1980), according to NASA, as the following graphic shows.  The past three months have a +0.63°C temperature anomaly.  And the latest 12-month period (May 2013 – Apr 2014) had a +0.62°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The 2010-2012 downturn was largely due to the last La Niña event (see below for more).  Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niño).  As previous anomalously cool months fell off the back of the running mean, the 12-month temperature trace tracked upward again throughout 2013 and 2014.

 photo NASA-Temp_Analysis_20140430_zps82150da6.gif

Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through April 2014 from NASA.

According to NOAA, April’s global average temperatures were +0.77°C (1.386°F) above the 20th century average of 13.7°C (56.7°F).  NOAA’s global temperature anomaly map for April (duplicated below) shows where conditions were warmer and cooler than average during the month.

 photo NOAA-Temp_Analysis_201404_zps92d3f6cb.gif

Figure 2. Global temperature anomaly map for August 2013 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same spatial temperature patterns and their relative strength.

Influence of ENSO

 photo NinoSSTAnom20140501_zpsc925f282.gif

Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is `NINO 3.4` (2nd time series from top).

There has been neither El Niño nor La Niña in the past couple of years.  This ENSO-neutral phase is common.  As you can see in the NINO 3.4 time series (2nd from top in Figure 3), Pacific sea surface temperatures were relatively cool in January through March, then quickly warmed.  This switch occurred because normal easterly winds (blowing toward the west) across the equatorial Pacific relaxed and two significant westerly wind bursts occurred in the western Pacific.  These anomalous winds generated an eastward moving Kelvin wave, which causes downwelling and surface mass convergence.  Warm SSTs collect along the equator as a result.  These Kelvin waves eventually crossed the entire Pacific Ocean, as Figure 4 shows.

 photo PacifcOcEqTAnomaly20140523_zpsff7554f1.gif

Figure 4.  Sub-surface Pacific Ocean temperature anomalies from Jan-Apr 2014.  Anomalously cool eastern Pacific Ocean temperatures in January gave way to anomalously warm temperatures by April.  Temperatures between 80W and 100W warmed further since April 14.

The Climate Prediction Center announced an El Niño Watch earlier this year.  The most recent update says the chances of an El Niño during the rest of 2014 exceeds 65%.  There is no reliable prediction of the potential El Niño’s strength at this time.  Without another westerly wind burst, an El Niño will likely not be very strong.  Even moderate strength El Niños impact global weather patterns.

An important detail is whether the potential 2014 El Niño will be an Eastern or Central Pacific El Niño (see figure below).  Professor Jin-Yi Yu, along with colleagues, first proposed the difference in a 2009 Journal of Climate paper.  More recently, Yu’s work suggested a recent trend toward Central Pacific El Niños influenced the frequency and intensity of recent U.S. droughts.  This type of El Niño doesn’t cause global record temperatures, but still impacts atmospheric circulations and the jet stream, which impacts which areas receive more or less rain.  If the potential 2014 El Niño is an Eastern Pacific type, we can expect monthly global mean temperatures to spike and the usual precipitation anomalies commonly attributed to El Niño.

 photo EastvsCentralPacificENSOschematic_zps08856e81.jpg

Figure 5. Schematic of Central-Pacific ENSO versus Eastern-Pacific ENSO as envisioned by Dr. Jin-Yi Yu at the University of California – Irvine.

If an El Niño does occur later in 2014, it will mask some of the deep ocean heat absorption by releasing energy back to the atmosphere.  If that happens, the second half of 2014 and the first half of 2015 will likely set global surface temperature records.  2014, 2015, or both could set the all-time global mean temperature record (currently held by 2010).  Some scientists recently postulated that an El Niño could also trigger a shift from the current negative phase of the Interdecadal Pacific Oscillation (IPO; or PDO for just the northern hemisphere) to a new positive phase.  This would be similar in nature, though different in detail, as the shift from La Niña or neutral conditions to El Niño.  If this happens, the likelihood of record hot years would increase.  I personally do not believe this El Niño will shift the IPO phase.  I don’t think this El Niño will be strong enough and I don’t think the IPO is in a conducive state for a switch to occur.

The “Hiatus”

Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: since an energy imbalance exists (less energy is leaving the Earth than the Earth is receiving; this is due to atmospheric greenhouse gases) and the surface temperature rise has seemingly stalled, the excess energy is going somewhere.  The heat has to go somewhere – energy doesn’t just disappear.  That somewhere is likely the oceans, and specifically the deep ocean (see figure below).  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising in part because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as introduce additional water vapor due to the warmer atmosphere.  Thus, the immediate warming rate might have slowed down, but we have locked in future warming (higher future warming rate).

 photo Ocean_heat_content_balmaseda_et_al_zps23184297.jpg

Figure 6. Recent research shows anomalous ocean heat energy locations since the late 1950s.  The purple lines in the graph show how the heat content of the whole ocean has changed over the past five decades. The blue lines represent only the top 700 m and the grey lines are just the top 300 m.  Source: Balmaseda et al., (2013)

You can see in Figure 6 that the upper 300m of the world’s oceans accumulated less heat during the 2000s (5*10^22 J) than during the 1990s.  In contrast, accumulated heat greatly increased in ocean waters between 300m and 700m during the 2000s (>10*10^22 J).  We cannot and do not observe the deep ocean with great frequency.  We do know from frequent and reliable observations that the sea surface and relatively shallow ocean did not absorb most of the heat in the past decade.  We also know how much energy came to and left the Earth from satellite observations.  If we know how much energy came in, how much left, and how much the land surface and shallow ocean absorbed, it is a relatively straightforward computation to determine how much energy likely remains in the deep ocean.

Discussion

The fact that April 2014 was the warmest on record despite a negative IPO and a neutral ENSO is eye-opening.  I think it highlights the fact that there is an even lower frequency signal underlying the IPO, ENSO, and April weather: anthropogenic warming.  That signal is not oscillatory, it is increasing at an increasing rate and will continue to do so for decades to centuries.  The length of time that occurs and its eventual magnitude is dependent on our policies and activities.  We continue to emit GHGs at or above the high-end of the range simulated by climate models.  Growth in fossil fuel use at the global scale continues.  This growth dwarfs any effect of a switch to energy sources with lower GHG emissions.  I don’t think that will change during the next 15 years, which would lock us into the warmer climate projections through most of the rest of the 21st century.  The primary reason for this is the scale of humankind’s energy infrastructure.  Switching from fossil fuels to renewable energy will take decades.  Acknowledging this isn’t defeatist or pessimistic; it is I think critical in order to identify appropriate opportunities and implement the type and scale of policy responses to encourage that switch.


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NASA & NOAA: August 2013 4th Warmest Globally On Record

According to data released by NASA and NOAA this month, August was the 4th warmest August globally on record.  Here are the data for NASA’s analysis; here are NOAA data and report.  The two agencies have different analysis techniques, which in this case resulted in different temperature anomaly values but the same overall rankings within their respective data sets.  The analyses result in different rankings in most months.  The two techniques do provide a check on one another and confidence for us that their results are robust.  At the beginning, I will remind readers that the month-to-month and year-to-year values and rankings matter less than the long-term climatic warming.  Monthly and yearly conditions changes primarily by the weather, which is not climate.

The details:

August’s global average temperature was 0.62°C (1.12°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The past three months have a +0.58°C temperature anomaly.  And the latest 12-month period (Aug 2012 – Jul 2013) had a +0.59°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The 2010-2012 downturn was largely due to the latest La Niña event (see below for more) that ended early last summer.  Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niño).  Therefore, as previous anomalously cool months fall off the back of the running mean, and barring another La Niña, the 12-month temperature trace should track upward again throughout 2013.

 photo NASA-Temp_Analysis_20130831_zps3ff2a250.gif

Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through August 2013 from NASA.

According to NOAA, April’s global average temperatures were 0.62°C (1.12°F) above the 20th century average of 15.6°C (60.1°F).  NOAA’s global temperature anomaly map for August (duplicated below) shows where conditions were warmer and cooler than average during the month.

 photo NOAA-Temp_Analysis_201308_zpsf2f24a41.gif

Figure 2. Global temperature anomaly map for August 2013 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

 photo NinoSSTAnom20130924_zps74ba969c.gif

Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

The last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, tropical Pacific sea-surface temperatures peaked at +0.8 (y-axis) in September 2012.  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012.  Recent ENSO events occurred at the same time that the Interdecadal Pacific Oscillation entered its most recent negative phase.  This phase acts like a La Niña, but its influence is smaller than La Niña.  So natural, low-frequency climate oscillations affect the globe’s temperatures.  Underlying these oscillations is the background warming caused by humans, which we detect by looking at long-term anomalies.  Despite these recent cooling influences, temperatures were still top-10 warmest for a calendar year (2012) and during individual months, including August 2013.

Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: since an energy imbalance exists (less energy is leaving the Earth than the Earth is receiving; this is due to atmospheric greenhouse gases) and the surface temperature rise has seemingly stalled, the excess energy is going somewhere.  The heat has to be going somewhere – energy doesn’t just disappear.  That somewhere is likely the oceans, and specifically the deep ocean (see figure below).  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising in part because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as introduce additional water vapor due to the warmer atmosphere.  Thus, the immediate warming rate might have slowed down, but we have locked in future warming (higher future warming rate).

 photo Ocean_heat_content_balmaseda_et_al_zps23184297.jpg

Figure 4. New research that shows anomalous ocean heat energy locations since the late 1950s.  The purple lines in the graph show how the heat content of the whole ocean has changed over the past five decades. The blue lines represent only the top 700 m and the grey lines are just the top 300 m.  Source: Balmaseda et al., (2013)

Paying for recovery from seemingly localized severe weather and climate events is and always will be more expensive than paying to increase resilience from those events.  As drought continues to impact the US, as Arctic ice continues its long-term melt, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades.  It is up to us how many costs we subject ourselves to.  As President Obama begins his second term with climate change “a priority”, he tosses aside the most effective tool available and most recommended by economists: a carbon tax.  Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm.  It is up to the citizens of this country, and others, to take the lead on this topic.  We have to demand common sense actions that will actually make a difference.

But be forewarned: even if we take action today, we will still see more warmest-ever La Niña years, more warmest-ever El Niño years, more drought, higher sea levels, increased ocean acidification, more plant stress, and more ecosystem stress.  The biggest difference between efforts in the 1980s and 1990s to scrub sulfur and CFC emissions and future efforts to reduce CO2 emissions is this: the first two yielded an almost immediate result.  It will take decades to centuries before CO2 emission reductions produce tangible results humans can see.  That is part of what makes climate change such a wicked problem.


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NASA & NOAA: April 2013 13th Warmest Globally On Record

According to data released by NASA and NOAA last week, April was the 13th warmest April globally on record.  Here are the data for  NASA’s analysis; here are NOAA data and report.  The two agencies have slightly different analysis techniques, which in this case resulted in different temperature anomaly values but the same overall rankings.  Most months, the analyses result in different rankings.  The two techniques do provide a check on one another and confidence for us that their results are robust.

The details:

April’s global average temperatures were 0.50°C (0.9°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The past three months have a +0.53°C temperature anomaly.  And the latest 12-month period (Apr 2012 – Mar 2013) had a +0.59°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The 2010-2012 downturn was largely due to the latest La Niña event (see below for more) that ended early last summer.  Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niñ0).  Therefore, as previous anomalously cool months fall off the back of the running mean, and barring another La Niña, the 12-month temperature trace should track upward again throughout 2013.

 photo NASA-Temp_Analysis_20130430_zpsd93c9d48.gif

Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through April 2013 from NASA.

According to NOAA, April’s global average temperatures were 0.52°C (0.94°F) above the 20th century mean of 13.7°C (56.7°F).  NOAA’s global temperature anomaly map for April (duplicated below) shows where conditions were warmer and cooler than average during the month.

 photo NOAA-Temp_Analysis_201304_zps204a8f35.gif

Figure 2. Global temperature anomaly map for January 2013 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

Both analyses show much cooler than normal conditions over most of North America, Europe, and northeast Asia.  As I’ve discussed elsewhere, this is in response to the abnormal jet stream.  Large, unmoving high pressure centers blocked the jet stream at different locations in the Northern Hemisphere multiple times this winter and spring.  The jet stream therefore assumed a high amplitude pattern where the trough and ridge axes were tens of degrees of latitude apart from one another.  When this happens, very cold air is pulled southward and warm air is pulled northward (look at central Eurasia).  In April 2013, the specific position of the high pressure centers caused cold air to spill southward over land as opposed to over the oceans.  These cold air outbreaks were an advantage for the US in that severe storms were unable to form.  This situation obviously broke down in the past couple of weeks and we have correspondingly seen devastating severe weather outbreaks across the south-central US.

During the second half of last year, a ENSO-neutral state (neither El Niño nor La Niña) began, which continues to this day:

 photo NinoSSTAnom20130501_zpsf742a7c0.gif

Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

The last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, tropical Pacific sea-surface temperatures peaked at +0.8 (y-axis) in September 2012.  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012.  So a natural, low-frequency climate oscillation affected the globe’s temperatures during the past couple of years.  Underlying that oscillation is the background warming caused by humans.  And yet temperatures were still in the top-10 warmest for a calendar year (2012) and individual months, including through March 2013, in recorded history.  We ascribe a certain status to top-10 events.  April 2013 obviously missed the top-10 threshold, but it remains close to that level of anomalous warmth.  However, the difference in temperature magnitude between the 10th and 13th warmest Aprils is measured in tenths of a degree.

Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: since an energy imbalance exists (less outgoing energy than incoming energy due to atmospheric greenhouse gases) and the surface temperature rise has seemingly stalled, the excess energy is going somewhere.  That somewhere is likely the oceans, and specifically the deep ocean (see figure below).  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising in part because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as introduce additional water vapor due to the warmer atmosphere.  Thus, the immediate warming rate might have slowed down, but we have locked in future warming (higher future warming rate).

 photo Ocean_heat_content_balmaseda_et_al_zps23184297.jpg

Figure 4. New research that shows anomalous ocean heat energy locations since the late 1950s.  The purple lines in the graph show how the heat content of the whole ocean has changed over the past five decades. The blue lines represent only the top 700 m and the grey lines are just the top 300 m.  Source: Balmaseda et al., (2013)

Paying for recovery from seemingly localized severe weather and climate events is and always will be more expensive than paying to increase resilience from those events.  As drought continues to impact US agriculture, as Arctic ice continues to melt to new record lows, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades.  It is up to us how many costs we subject ourselves to.  As President Obama begins his second term with climate change “a priority”, he tosses aside the most effective tool available and most recommended by economists: a carbon tax.  Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm.  It is up to the citizens of this country, and others, to take the lead on this topic.  We have to demand common sense actions that will actually make a difference.  But be forewarned: even if we take action today, we will still see more warmest-ever La Niña years, more warmest-ever El Niño years, more drought, higher sea levels, increased ocean acidification, more plant stress, and more ecosystem stress.  The biggest difference between efforts in the 1980s and 1990s to scrub sulfur and CFC emissions and future efforts to reduce CO2 emissions is this: the first two yielded an almost immediate result while it will take decades to centuries before CO2 emission reductions produce tangible results humans can see.  That is part of what makes climate change such a wicked problem.


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NASA & NOAA: March 2013 9th, 10th Warmest Globally On Record

According to data released by NOAA, March was the 10th warmest globally on record.  Here are the NOAA data and report.  NASA also released their suite of graphics, but their surface temperature data page is down today, so I cannot relay how NASA’s March temperature compares to historical Marches.  Once their site is back up, I will update this post.  [Update: NASA's analysis resulted in their 9th warmest March on record.  Here are the data for  NASA’s analysis.] The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but somewhat different rankings as well.  The two techniques provide a check on one another and confidence for us.

The details:

March’s global average temperatures were 0.59°C (1.062°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The past three months have a +0.57°C temperature anomaly.  And the latest 12-month period (Apr 2012 – Mar 2013) had a +0.60°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The recent downturn (2010-2012) was largely due to the latest La Niña event (see below for more) that ended early last summer.  Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niñ0).  Therefore, as previous anomalously cool months fall off the back of the running mean, and barring another La Niña, the 12-month temperature trace should track upward again throughout 2013.

 photo NASA-Temp_Analysis_20130331_zps2e2b340a.gif

Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through March 2013 from NASA.

According to NOAA, March’s global average temperatures were 0.58°C (1.044°F) above the 20th century mean of 12.7°C (54.9°F).  NOAA’s global temperature anomaly map for March (duplicated below) shows where conditions were warmer than average during the month.

 photo GlobalTemperatureAnomalyMap201303_zpsf432fd9b.gif

Figure 2. Global temperature anomaly map for March 2013 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite small differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

The very warm conditions found over Greenland are a concern.  Greenland was warmer than average during more months in recent history than not.  In contrast to 2012, northern Eurasian temperatures were much cooler than normal.  This is likely a temporary, seasonal effect.  Long-term temperatures over much of this region continue to rise at among the fastest rate for any region on Earth.

The NASA and NOAA surface temperature maps correlate well with the 500-mb height pressure anomalies, as seen in this graph:

 photo NOAA500hPaanomalymap201303_zps6d024aed.gif

Figure 3. 500-mb heights (white contours) and anomalies (m; color contours) during March 2013.

Note the correspondence between the height map and the NASA & NOAA surface temperature maps: lower heights (negative height anomalies) present over the North Atlantic and northern Eurasia overlay the cold surface temperature anomalies at the surface.  Similarly, warm surface temperature anomalies are located under the positive 500-mb height anomalies.

These temperature observations are of interest for the following reason: the globe came out of a moderate La Niña event in the first half of last year.  During the second half of the 2012 and the first part of 2013, we remained in a ENSO-neutral state (neither El Niño nor La Niña):

 photo NinoSSTAnom20130401_zpsf59ac6f7.gif

Figure 4. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

The last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, tropical Pacific sea-surface temperatures peaked at +0.8 (y-axis) in September 2012.  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012.  So a natural, low-frequency climate oscillation affected the globe’s temperatures during the past couple of years.  Underlying that oscillation is the background warming caused by humans.  And yet temperatures were still in the top-10 warmest for a calendar year (2012) and individual months, including March 2013, in recorded history.

Skeptics have pointed out that warming has “stopped” in recent years (by comparing recent temperatures to the 1998 maximum which was heavily influenced by a strong El Niño even), which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: a global annual energy imbalance exists (less outgoing energy than incoming energy).  If the surface temperature rise has seemingly stalled, the excess energy is going somewhere.  That somewhere is likely the oceans, and specifically the deep ocean (see the figures below).  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising in part because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as introduce additional water vapor.  Thus, the short-term warming rate might have slowed down, but we have locked in future warming (higher future warming rate) as well as future climate effects.

 photo Total-Heat-Content.gif

Figure 5. Total global heat content anomaly from 1950-2004. An overwhelming majority of energy went to the global oceans.

 photo Ocean_heat_content_balmaseda_et_al_zps23184297.jpg

Figure 6. New research that shows anomalous ocean heat energy location since the late 1950s.  The purple lines in the graph show how the heat content of the whole ocean has changed over the past five decades. The blue lines represent only the top 700 m and the grey lines are just the top 300 m.  Source: Balmaseda et al., (2013)

Balmaseda et al.’s work demonstrates the transport of anomalous energy through the depth of the global oceans.  Note that the grey lines’ lack of significant change from 2004-2008 (upper 300m).  Observations of surface temperature include the very top part of this 300m layer.  Since the layer hasn’t changed much, neither have surface temperature readings.  Note the rapid increase in heat content within the top 700m.  Given the lack of increase in the top 300m, the 300-700m layer heat content must have increased.  By the same logic, the rapid growth in heat content throughout the depth of the ocean, which did not stall post-2004, provides evidence for anomalous heat location.  You can also see the impact of major volcanic eruptions on ocean heat content: less incoming solar radiation means less absorbed heat.

A significant question for climate scientists is this: are climate models capable of picking up this heat anomaly signal and do they show a similar trend?  If they aren’t, then their projections of surface temperature change is likely to be incorrect since the heat is warming the abyssal ocean and not the land and atmosphere in the 2000s and 2010s.  If they aren’t, climate policy is also impacted.  Instead of warmer surface temperatures (and effects on drought, agriculture, and health to name just a few), anomalous ocean heat content will impact coastal communities more than previously thought.  Consider the implications of that in addition to the AR4’s lack of consideration of land-based ice melt: sea level projections could be too conservative.

That said, it is also a fair question to ask whether today’s climate policies are sufficient for today’s climate.  In many cases, I would say  they aren’t sufficient.  Paying for recovery from seemingly localized severe weather and climate events is and always will be more expensive than paying to increase resilience from those events.  As drought continues to impact US agriculture, as Arctic ice continues to melt to new record lows, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades.  It is up to us how many costs we subject ourselves to.

As President Obama began his second term with climate change “a priority”, he tosses aside the most effective tool available and most recommended by economists: a carbon tax.  Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm.  It is up to the citizens of this country, and others, to take the lead on this topic.  We have to demand common sense actions that will actually make a difference.  But be forewarned: even if we take action today, we will still see more warmest La Niña years, more warmest El Niño years, more drought, higher sea levels, increased ocean acidification, more plant stress, and more ecosystem stress.  The biggest difference between efforts in the 1980s and 1990s to scrub sulfur and CFC emissions and future efforts to reduce CO2 emissions is this: the first two yielded an almost immediate result while it will take decades before CO2 emission reductions produce tangible results humans can see.


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NASA & NOAA: January 2013 Was 6th, 9th Warmest Globally On Record

According to data released by NASA and NOAA last week, January was the 6th and 9th warmest January’s (respectively) globally on record.  Here are the data for  NASA’s analysis; here are NOAA data and report.  The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but somewhat different rankings as well.  The two techniques provide a check on one another and confidence for us.

The details:

January’s global average temperatures were 0.61°C (1.098°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The warmest regions on Earth coincide with the locations where climate models have been projecting the most warmth will occur: high latitudes (especially within the Arctic Circle).  The past three months have a +0.58°C temperature anomaly.  And the latest 12-month period (Feb 2012 – Jan 2013) had a +0.58°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The recent downturn (2010-2012) is largely due to the latest La Niña event (see below for more) that ended early last summer.  Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niñ0).  Therefore, as previous anomalously cool months fall off the back of the running mean, and barring another La Niña, the 12-month temperature trace should track upward again in 2013.

 photo NASA-Temp_Analysis_20130131_zpsdfcedaac.gif

Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through January 2013 from NASA.

According to NOAA, January’s global average temperatures were 0.54°C (0.97°F) above the 20th century mean of 14.0°C (57.2°F).  NOAA’s global temperature anomaly map for January (duplicated below) shows where conditions were warmer than average during the month.

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Figure 2. Global temperature anomaly map for January 2013 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

The very warm conditions found over Greenland and Alaska are a concern.  These areas were warmer than average during more months in recent history than not.  Additionally, Australia was much warmer than usual.  Indeed, Australia’s January average temperature was the highest on record: +2.28°C (4.10°F!) above the 1961–1990 average, besting the previous record set in 1932 by 0.11°C (0.20°F).  In contrast to 2012, Siberian temperatures were cooler than normal.  This is likely a temporary, seasonal effect.  Long-term temperatures over northern Siberia continue to rise at among the fastest rate for any region on Earth.

These observations are also worrisome for the following reason: the globe came out of a moderate La Niña event in the first half of the year.  During the second half of the year, we remained in a ENSO-neutral state (neither El Niño nor La Niña):

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Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

The last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, tropical Pacific sea-surface temperatures peaked at +0.8 (y-axis) in September 2012.  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012.  So a natural, low-frequency climate oscillation affected the globe’s temperatures during the past couple of years.  Underlying that oscillation is the background warming caused by humans.  And yet temperatures were still in the top-10 warmest for a calendar year (2012) and individual months, including January 2013, in recorded history.

Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: since an energy imbalance exists (less outgoing energy than incoming energy) and the surface temperature rise has seemingly stalled, the excess energy is going somewhere.  That somewhere is likely the oceans, and specifically the deep ocean.  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as additional water vapor.  Thus, the immediate warming rate might have slowed down, but we have locked in future warming (higher future warming rate).

In a previous post on global temperatures, I pointed a few things out and asked some questions.  The Conference of Parties summit produced no meaningful climate action (November 2012).  Countries agreed to have something on paper by 2015 and enacted by 2020.  If everything goes as planned (a huge assumption given the lack of historical progress), significant carbon reductions wouldn’t occur until later in the 2020s – too late to ensure <2°C warming by 2100.  If, as is much more likely, everything doesn’t go as planned, reductions wouldn’t occur until later than the 2020s.  Additional meetings are scheduled for this year, but I maintain my expectation that nothing meaningful will come from them.  The international process is ill-equipped to handle all the legitimate interest groups in one fell swoop.

Instead, actions that start locally and grow with time are more likely to address emissions and eventual warming and other climate change effects.  People started small-scale activities in cities around the world in recent years.  There are also regional and international carbon markets.  While most markets were poorly designed, lessons learned from the first generation can be used to make future generation markets more effective.  As these small-scale efforts grow and their effects combine, larger bodies will need to address differences between them so that they work for larger populations and markets.

Paying for recovery from seemingly localized severe weather and climate events is and always will be more expensive than paying to increase resilience from those events.  As drought continues to impact US agriculture, as Arctic ice continues to melt to new record lows, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades.  It is up to us how many costs we subject ourselves to.  As President Obama begins his second term with climate change “a priority”, he tosses aside the most effective tool available and most recommended by economists: a carbon tax.  Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm.  It is up to the citizens of this country, and others, to take the lead on this topic.  We have to demand common sense actions that will actually make a difference.  But be forewarned: even if we take action today, we will still see more warmest La Niña years, more warmest El Niño years, more drought, higher sea levels, increased ocean acidification, more plant stress, and more ecosystem stress.  The biggest difference between efforts in the 1980s and 1990s to scrub sulfur and CFC emissions and future efforts to reduce CO2 emissions is this: the first two yielded an almost immediate result while it will take decades before CO2 emission reductions produce tangible results humans can see.


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NASA & NOAA: 2012 Was In Top-10 Warmest Years For Globe On Record

According to data released by NASA and NOAA this week, 2012 was the 9th and 10th warmest years (respectively) globally on record.  NASA’s analysis produced the 9th warmest year in its dataset; NOAA recorded the 10th warmest year in its dataset.  The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but somewhat different rankings as well.

The details:

2012’s global average temperature was +0.56°C (1°F) warmer than the 1951-1980 base period average (1951-1980), according to NASA, as the following graphic shows.  The warmest regions on Earth (by anomaly) were the Arctic and central North America.  The fall months have a +0.68°C temperature anomaly, which was the highest three-month anomaly in 2012 due to the absence of La Niña.  In contrast, Dec-Jan-Feb produced the lowest temperature anomaly of the year because of the preceding La Niña, which was moderate in strength.  And the latest 12-month period (Nov 2011 – Oct 2012) had a +0.53°C temperature anomaly.  This anomaly is likely to grow larger in the first part of 2013 as the early months of 2012 (influenced by La Niña) slide off.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The recent downturn (2010 to 2012) shows the effect of the latest La Niña event (see below for more) that ended in early 2012.  During the summer of 2012, ENSO conditions returned to a neutral state.  Therefore, the temperature trace (12-mo running mean) should track upward again as we proceed through 2013.

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Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through December 2012 from NASA.

According to NOAA, 2012’s global average temperatures were 0.57°C (1.03°F) above the 20th century mean of 13.9°C (57.0°F).  NOAA’s global temperature anomaly map for 2012 (duplicated below) reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.

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Figure 2. Global temperature anomaly map for 2012 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

The continued anomalous warmth over Siberia is especially worrisome due to the vast methane reserves locked into the tundra and under the seabed near the region.  Methane is a stronger greenhouse gas than carbon dioxide over short time-frames (<100y),which is the leading cause of the warmth we’re now witnessing. As I discussed in the comments in post this summer, the warming signal from methane likely hasn’t been captured yet since the yearly natural variability and the CO2-caused warming signals are much stronger.  It is likely that we will not detect the methane signal for many more years.

These observations are also worrisome for the following reason: the globe came out of a moderate La Niña event in the first half of the year.  During the second half of the year, we remained in a ENSO-neutral state (neither El Niño nor La Niña):

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Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

As the second time series graph (labeled NINO3.4) shows, the last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, SSTs peaked at +0.8 in September (y-axis).  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012.  So the globe’s temperatures were affected by a natural, low-frequency climate oscillation during the past couple of years.  And yet temperatures were still in the top-10 warmest for a calendar year in recorded history.

Indeed, this was the warmest La Niña year on record:

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Figure 4. Anomalies of annual global temperature as measured by NOAA.  Blue bars represent La Niña years, red bars represent El Niño years, and gray bars represent ENSO-neutral years.

This figure shows that 2012 edged out 2011 as the warmest La Niña year on record (since 1950).  It also shows a clear trend seen in every temperature record of this length: La Niña years are getting warmer with time (note the difference between 2012 and 1956, for instance).  El Niño years are getting warmer with time (note the difference between 2010 and 1958).  ENSO-neutral years are getting warmer with time.  The globe got warmer throughout the 20th and into the 21st century.  Do not pay too much attention to any single year as “evidence” that global warming stopped.  As I stated above, natural low-frequency climate oscillations introduce a lot of noise into the temperature signal.  Climate is measured over decades and the decadal trend is obvious here: warmer with time.

Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic.  What is likely going on is quite different: if an energy imbalance exists (less outgoing energy than incoming) and the surface temperature rise has seemingly stalled, the excess energy has to be going somewhere.  That somewhere is likely to be the oceans, and specifically the deep ocean.  Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications.  If you add heat to a material, it expands.  The ocean is no different; sea-levels are rising because of heat added to it in the past.  The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen.  Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as additional water vapor.  Thus, the immediate warming might have slowed down, but we have locked in future warming.

In my previous post on global temperatures, I pointed a few things out and asked some questions.  The Conference of Parties summit produced no meaningful climate action.  Countries agreed to have something on paper by 2015 and enacted by 2020.  If everything goes as planned, significant carbon reductions wouldn’t occur until later in the 2020s – too late to ensure <2°C warming by 2100.  If, as is much more likely, everything doesn’t go as planned, reductions wouldn’t occur until later than the 2020s.  Additional meetings are scheduled for later this year, but I maintain my expectation that nothing meaningful will come from them.  The international process is ill-equipped to handle all the legitimate interest groups in one fell swoop.

The northeast continues to recover from Superstorm Sandy.  New York and New Jersey began to plan for infrastructure with increased resilience from the next storm, which will eventually hit the area.  Congress took way too long to approve relief money (months, instead of days as it did after Katrina).  $60 billion will go a long ways toward assisting the region, especially if people take seriously the threat of living next to the ocean, which has been uncharacteristically quiet for decades.

Paying for recovery is and always will be more expensive than paying to increase resilience from disasters.  As drought continues to impact US agriculture, as Arctic ice continues to melt to new record lows, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades.  It is up to us how much grief we subject ourselves to.  As President Obama begins his second term and climate change “will be a priority in his second term”, he tosses aside the tool most recommended by economists: a carbon tax.  Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm.  It is up to the citizens of this country, and others, to take the lead on this topic.  We have to demand common sense actions that will actually make a difference.  But be forewarned: even if we take action today, we will still see more warmest La Niña years, more warmest El Niño years, more ENSO-neutral years.


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NASA & NOAA: October 2012 Was 2nd, 4th Warmest On Record

According to data released by NASA and NOAA this week, October 2012 was the 2nd and 4th warmest October’s (respectively) globally on record.  NASA’s analysis produced the 2nd warmest October in its dataset; NOAA recorded the 4th warmest October in its dataset.  The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but somewhat different rankings as well.

The details:

October’s global average temperatures were 0.69°C (1.24°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The warmest regions on Earth coincide with the locations where climate models have been projecting the most warmth to occur for years: high latitudes (especially within the Arctic Circle in July 2012).  The past three months have a +0.63°C temperature anomaly.  And the latest 12-month period (Nov 2011 – Oct 2012) had a +0.51°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The recent downturn (post-2010) is largely due to the latest La Niña event (see below for more) that recently ended.  ENSO conditions returned to a neutral state.  Therefore, the temperature trace (12-mo running mean) should track upward again, especially as cooler months fall off the running mean.

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Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through October 2012 from NASA.

According to NOAA, October’s global average temperatures were 0.63°C (1.13°F) above the 20th century mean of 14.0°C (57.2°F).  NOAA’s global temperature anomaly map for October (duplicated below) reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.

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Figure 2. Global temperature anomaly map for October 2012 from NOAA.

The two different analyses’ importance is also shown by the preceding two figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

The continued anomalous warmth over Siberia is especially worrisome due to the vast methane reserves locked into the tundra and under the seabed near the region.  Methane is a stronger greenhouse gas than carbon dioxide over short time-frames (<100y),which is the leading cause of the warmth we’re now witnessing. As I discussed in the comments in post this summer, the warming signal from methane likely hasn’t been captured yet since the yearly natural variability and the CO2-caused warming signals are much stronger.  It is likely that we will not detect the methane signal for many more years.

Of additional concern are the very warm conditions found over Greenland.  Indeed, record warmth was observed at a 3200m altitude station in early July.  3.6°C may not sound that warm in July, but the station’s location at 10,500ft altitude is of interest.  In contrast, continued warmth over portions of Greenland that have not witnessed such warmth did result in rapid melting during 2012.  There was recent news that described how much faster melt has occurred over Greenland (see associated picture) than expected in the IPCC AR4.  While the record-setting sea ice melt across the Arctic Ocean this year is important in some respects, at least melting sea ice doesn’t contribute to sea level rise.  The opposite is true for Greenland melt: every drop that makes it to the ocean raises the level.  When the melt is happening 3X faster than just 20 years ago, it’s time to pay attention (note: not panic!).

These observations are also worrisome for the following reason: the globe is experiencing ENSO-neutral conditions:

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Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

As the second time series graph (labeled NINO3.4) shows, the last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, SSTs peaked at +0.8 in September (y-axis).  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2009 to 2011.  Note that the darker lines (running means) started to increase at the end of 2011, following the higher frequency monthly data.  ENSO-nuetral conditions are expected to continue through the next 3-6 months, after which a new El Niño event might begin.

As the globe returns to ENSO-neutral conditions this winter, how will global temperatures respond?  Remember that global temperatures typically trail ENSO conditions by 3-6 months: the recent tropical Pacific warming trend should therefore help boost global temperatures back to their most natural state (i.e., without an ENSO (La Niña) signal on top of it, although other important signals might also occur at any particular point in time).

So what do we do?  I hope most readers are aware that the 18th Conference of Parties (COP-18) meeting is currently underway in Doha, Qatar.  I’ve stated my opinion before that I don’t think putting every country in the world around the table to negotiate a climate treaty is the most appropriate approach.  Canada, Russia, and Japan removed themselves from the Kyoto Protocol recently, which means that the only large emitters left are from the European Union.  I actually think that’s more appropriate: I prefer regional and bilateral agreements – countries should have pursued them more aggressively in the past 30 years.

More to the point, we should focus on  bottom-up approaches.  There are smaller groups of people who, if provided the right type of expertise and resources when needed, could probably enact changes that will result in decreasing emissions as well as successful adaptation policies.  The developed world is decarbonizing, but not fast enough yet.  I also recommend you watch China.  They invested very large sums of money in renewable energy and other green efforts.  That money will bear fruit in the future.  The rub, of course, is we cannot accurately predict when and how today.  It will also be interesting to see how the northeast U.S. reacts to Hurricane Sandy.  They have to rebuild infrastructure.  Will they include adaptive measures while they’re at it or will they kick the can down the road?


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State of the Poles – Mid-September 2012: Record Low Arctic Ice Extent; Antarctic Ice Above Climatological Normal

Judging by recent search terms used to get to this blog and the relative recent peak in traffic, readers have been searching for this post.  I wanted to wait a little longer into the month so that I could capture the expected Arctic minimum, which officially occurred on the 16th of September.  The NSIDC announced this date, after which I started gathering the plots that are found below.  This post will be longer than it usually is because this year’s minimum shattered the record minimum set in 2007, which shattered the previous record set in 2005.  Most of the post is made up of figures, so I encourage readers to at least view them to get a good picture of today’s conditions.  I’m purposefully framing things this way to relay the truly stunning situation the Arctic is in today.  2012 is additional proof the Arctic cryosphere is searching for a new stable point, but hasn’t found it yet.  That does not bode well for the rest of the globe.  With that, let’s begin.

The state of global polar sea ice area in mid-September 2012 remains significantly below climatological normal conditions (1979-2009).  Arctic sea ice loss is solely responsible for this condition.  In fact, if Antarctic sea ice were closer to its normal value, the global area would be much lower than it is today.  Arctic sea ice melted quickly in August and the first half of September because it was thinner than usual and winds helped push ice out of the Arctic where it could melt at lower latitudes; Antarctic sea ice has refrozen at a faster than normal rate during the austral winter.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area late last year to a +750,000 sq. km. anomaly in March 2012 before falling back to a -2.2 million sq. km. deficit earlier this month.

After starting the year at a deficit from normal conditions, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011 (i.e., almost the entire calendary year).  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  The last time global sea ice area remained near 19 million sq. km. during May was in 2007, when the Arctic extent hit its modern day record minimum.  The maximum in the boreal spring the past two years was ~19.5 million sq. km.

Conditions were prime for another modern-day record sea ice extent minimum to occur in September.  Specific weather conditions helped to determine how 2012′s extent minimum ranks compared to the last 33 years, but it was the overall poor condition of Arctic sea ice that contributed to this year’s record low values.

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NASA & NOAA: July 2012 Was 12th, 4th Warmest On Record

According to data released by NASA and NOAA this week, July 2012 was the 12th and 4th warmest July (respectively) globally on record.  NASA’s analysis produced the 12th warmest July in its dataset; NOAA recorded the 4th warmest July in its dataset.  The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but rather different rankings as well.

The details:

July’s global average temperatures were 0.47°C (0.85°F) above normal (1951-1980), according to NASA, as the following graphic shows.  The warmest regions on Earth coincide with the locations where climate models have been projecting the most warmth to occur for years: high latitudes (especially within the Arctic Circle in July 2012).  The past three months have a +0.56°C temperature anomaly.  And the latest 12-month period (Aug 2011 – Jul 2012) had a +0.50°C temperature anomaly.  The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index.  The recent downturn (post-2010) is largely due to the latest La Niña event (see below for more) that recently ended.  As ENSO conditions return to neutral or even El Niño-like, the temperature trace should track upward again.

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Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through July 2012 from NASA.

According to NOAA, July’s global average temperatures were 0.63°C (1.13°F) above the 20th century mean of 15.2°C (1.12°F).  NOAA’s global temperature anomaly map for July (duplicated below) reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.  Unfortunately in July 2012, almost the entire Northern Hemisphere was warmer than normal.

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Figure 2. Global temperature anomaly map for July 2012 from NOAA.

These figures show just how extreme (intensity & spatial extent) the heat wave over most of the US was during July 2012.  As many people saw during the preceding two-and-a-half weeks, England was cooler than usual.  The same was true for northwestern Europe, most of Australia, and a good portion of South America (Argentina, Bolivia, etc.)  Additional anomalous warmth occurred over Greenland, Russia, eastern Europe, and into central Asia and the Middle East.  The two different analyses’ importance is also shown by these figures.  Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.

The continued anomalous warmth over Siberia is especially worrisome due to the vast methane reserves locked into the tundra and under the seabed near the region.  Methane is a stronger greenhouse gas than carbon dioxide over short time-frames (<100y),which is the leading cause of the warmth we’re now witnessing. As I discussed in the comments in a recent post, the warming signal from methane likely hasn’t been captured yet since the yearly natural variability and the CO2-caused warming signals are much stronger.  It is likely that we will not detect the methane signal for many more years.  Of additional concern are the very warm conditions found over Greenland.  Indeed, record warmth was observed at a 3200m altitude station in early July.  3.6°C may not sound that warm in July, but the station’s location at 10,500ft altitude is of interest.  I want to post more on this later, but the early July melt occurred over a very short time period, which did not result in a great deal of runoff.  In contrast, continued warmth over portions of Greenland that have not witnessed such warmth did result in rapid melting during 2012 (note: the melt season isn’t over yet either).

These observations are also worrisome for the following reason: the globe is still returning to ENSO-neutral conditions:

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Figure 3. Time series of weekly SST data from NCEP (NOAA).  The highest interest region for El Niño/La Niña is NINO 3.4 (2nd time series from top).

As the second time series graph (labeled NINO3.4) shows, the last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012.  Since then, SSTs have slowly warmed back above a +0.5°C-1.0°C anomaly (y-axis).  La Niña is a cooling event of the tropical Pacific Ocean that has time-delayed effects across the globe.  It is therefore significant that the past handful of months’ global temperatures continued to rank in or near the top-5 warmest in the modern era.  You can see the effect on global temperatures that the last La Niña had via this NASA time series.  Both the sea surface temperature and land surface temperature time series decreased from 2009 to 2011.  Note that the darker lines (running means) started to increase at the end of 2011, following the higher frequency monthly data.

As the globe returns to ENSO-neutral conditions this summer and early fall, how will global temperatures respond?  Remember that global temperatures typically trail ENSO conditions by 3-6 months: the recent tropical Pacific warming trend should therefore help boost global temperatures back to their most natural state (i.e., without an ENSO signal on top of it, although other important signals might also occur at any particular point in time).  Looking further into the future, what will next year’s temperatures be as the next El Niño develops, as predicted by a number of methods (see figure below)?

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Figure 5. Set of mid-July predictions of ENSO conditions by various models (dynamical and statistical).  To be considered an El Niño event, 3-month average temperature anomalies must be measured above +0.5°C for 5 consecutive months (so the earliest an El Niño event is likely to be announced is sometime this fall).  Approximately 1/2 of the models are predicting a new El Niño event by the end of this year.  The other models predict ENSO-neutral conditions through next spring.

From the above, I hope it is clear that the US’s recent record heat wave and historic drought are associated with the most recent La Niña event.  This is typical for the US, given dominant wind patterns that La Niña establishes.  While El Niño would add additional anomalous warmth on top of the slowly evolving climate change signal, it usually also heralds above-average precipitation over most of the US.  That would be a welcome event, given the reach and severity of the drought currently underway.


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State of the Poles – August 2012: Arctic Ice Extent At Record Lows; Antarctic Ice Near Climatological Normal

The state of global polar sea ice area in early August 2012 remains significantly below climatological normal conditions (1979-2009).  Arctic sea ice loss is solely responsible for this condition during this boreal summer.  Arctic sea ice melted quickly in July because it was thinner than usual and winds helped push ice out of the Arctic where it could melt at lower latitudes; Antarctic sea ice has refrozen at a slightly above normal rate during the austral winter.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area late last year to a +750,000 sq. km. anomaly in March 2012 before falling back to a -1.8 million sq. km. deficit.

After starting the year at a deficit from normal conditions last year, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011.  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  Conditions were slightly “better” than they were in 2007 or even in 2011 during July.  As we know from past experience, that can change rather quickly as Arctic sea ice melts in August and early September on its way to its yearly minimum.

Conditions are prime for another modern-day record sea ice extent minimum to occur in early September.  Specific weather conditions over the next month will determine how 2012′s extent minimum ranks compared to the last 33 years.  There is a very impressive low pressure system currently in the Arctic Ocean; a strong storm that normally doesn’t occur in July/August.  This might seem at first to indicate that sea ice melt might not occur, but the energy being exerted on the ocean and ice is actually more likely to assist in ice melt.  This is because of the turbulent motion imparted on the ocean by the storm’s winds, which repeatedly submerge ice in warmer water.  The winds also bring warmer sub-surface water up to the surface.  After the storm clears and within the following week, we shall see what effects the storm had on the thin Arctic ice.  The concentration maps below in particular will take a few days to report the effect – they are five-day averages of measurements so that spurious data do not unduly affect ice condition assessment.

Arctic Ice

According to the NSIDC, the weather conditions that caused less freezing to occur on the Atlantic side of the Arctic Ocean and more freezing on the Pacific side shifted in late spring/early summer this year to conditions that aided rapid melting across the Arctic – a continuation of similar events in the past six years.  Sea ice melt during July was not the fastest on record: 2.97 million sq. km. vs. 3.53 million sq. km. in July 2007!  Still, July′s extent was far below average for the month, as some of the graphs below demonstrate.  In fact, the extent set multiple daily record lows in July, as shown by one of the graphs below.  Arctic sea ice extent on in July averaged 7.94 million sq. km.  Ice in the Laptev, East Siberian and Kara Seas remained very much below normal, themselves setting daily record lows during July.  The Bering Sea, which saw ice extent growth due to anomalous northerly winds in the late winter/early spring witnessed the record high extent melt back to zero in an extremely short time period earlier this year.  The NSIDC included the following in their analysis:

Temperatures at the 925 hPa level (about 3,000 feet above the ocean surface) were typically 1 to 3 degrees Celsius (1.8 to 5.4 degrees Fahrenheit) above the 1981 to 2010 average over the Beaufort Sea and regions to the north, as well as over Baffin Bay. By contrast, temperatures were 1 to 3 degrees Celsius below average over the Norwegian Sea.

In terms of longer, climatological trends, Arctic sea ice extent in July has decreased linearly by 7.1% per decade.  This rate is lowest in the spring months and highest in late summer/early fall months.  Note that this rate also uses 1979-2000 as the climatological normal.  There is no reason to expect this rate to change significantly (more or less negative) any time soon.  Additional low ice seasons will continue.  Some years will see less decline than other years (like this past year) – but the multi-decadal trend is clear: significantly negative.  The specific value for any given month during any given year is, of course, influenced by local and temporary weather conditions.  But it has become clearer every year that humans helped establish a new normal in the Arctic with respect to sea ice.  This new normal will continue to have far-reaching implications on the weather in the mid-latitudes, where most people live.

Arctic Pictures and Graphs

The following graphic is a satellite representation of Arctic ice as of July 7, 2012:

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Figure 1 – UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20120707.

Compare this with August 6th’s satellite representation, also centered on the North Pole:

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Figure 2UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20120806.

The sea ice in the Canadian archipelago and along the northern coast of Russia determine whether the Northwest and Northeast passages open up or not.  You can see by comparing the two graphs that the ice is nearly completely melted in the Canadian archipelago.  The ice is also mostly melted along the entire northern coast of Russia – just a little remains in the Eastern Siberian sea.  Last year, both passages opened again.  I continue to think that the Northern Passage will likely open sometime this month.  The Northeastern Passage might not open this year, but if it doesn’t, it won’t do so by a thin margin.  You can also see in Figure 2 that the dominant wind direction has been toward Greenland.  This allows ice to stack up against a landmass and not be exported as quickly out into the Atlantic Ocean where it is likelier to melt.  The aforementioned Arctic Ocean storm has shifted wind direction somewhat across the basin, so I don’t expect all of the ice in Figure 2 to remain come September.

Overall, the health of the remaining ice pack is not healthy, as the following graph of Arctic ice volume from the end of July demonstrates:

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Figure 3PIOMAS Arctic sea ice volume time series through July 2012.

As the graph shows, volume hit another record minimum in June 2012.  Moreover, the volume is far, far outside the 2 standard deviation envelope (lighter gray contour surrounding the darker gray contour and blue median value).  Figure 3 demonstrates how anomalous conditions are for sea ice in the Arctic.  The volume has exceed the -4 standard deviation this year as well as the past two years.   I understand that most readers don’t have an excellent handle on statistics, but conditions between -1 and -2 standard deviations are not very common; conditions outside the -2 standard deviation threshold (see the line below the shaded area on the graph above) are incredibly rare: the chances of 3 of them occurring in 3 subsequent years under normal conditions are extraordinarily low.  Hence my assessment that “normal” conditions in the Arctic are shifting from what they were in the past few centuries: a new normal is developing.  Note further that after conditions returned to near the -1 standard deviation envelope in late 2011/early 2012, as it did in early 2011, volume has once again fallen rapidly outside of the -2 standard deviation area.  That means that natural conditions are not the likely cause; rather, another cause is much more likely to be responsible for this behavior.

I found a new graph that shows this and some additional information in a slightly different way:

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Figure 4 – PIOMAS Arctic Sea Ice Volume from 1980 through July 2012.

This figure shows volume as a function of date.  2012 is the red curve, which is plotted against the average volume of 2010 through July 2012 (yellow), the average volume of the 2000s (green), the average volume of the 1990s (blue), and the average value of the 1980s (violet).  Individuals years from 1979-2011 are indicated by the light gray curves.  It is once again clear how anomalous recent conditions are compared to conditions from the latter part of the 20th century.  It further shows how rapidly conditions have changed: the volume differences implied by this graph are astounding.  The minimum volume typically occurs in early September, which we are approaching again in 2012.

Switching back from volume to area, take a look at July’s areal extent time series data:

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Figure 5NSIDC Arctic sea ice extent time series through early August 2012.

This is the time series graph that the NSIDC occasionally includes in their monthly reports.  I present only this graph and not the graph updated daily throughout the month because of the historical context this graph provides.  The ice that piled up in the winter wasn’t thick enough to prevent rapid melt to occur (see early June 2012).  The effect of the thickening over the winter on September’s minimum extent will indicate how helpful the early season winds were in building sea ice that doesn’t melt every year back up.  Right now, the situation doesn’t look good for September extent.  During June, as I wrote above, melting occurred at record rate, resulting in a return to record low extent conditions by the middle of June.  2012′s extent has been below 2007′s for over two months and has been challenging all-time daily record minimums for almost two months.  You can also see in this time series graph that conditions since 2007 have clearly differed from the normal conditions established from 1979-2000 (light gray contours surrounding the dark gray mean value).

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Figure 6 – NSIDC northern hemisphere sea ice area (not extent) from the past two years only (blue) and the 1979-2008 mean (gray).  The red curve shows the anomaly from the mean.

Note in Figure 6 how low the sea ice area is in the beginning of August 2012: -2.157 million sq. km.!  Note two additional things. 1) The 2012 area value already is less than the climatological mean value by ~1.5 million sq. km.  2) The 2012 area value is only ~0.5 million sq. km. higher than the minimum recorded in 2011.  The area value has slid just slightly under 3 million sq. km. only twice before: 2007 and 2011.  Unless weather conditions change radically in the next couple of weeks, 2012 is also very likely to witness another sea ice area value under 3 million sq. km.  The link above also shows that sea ice area was lower than 4 million sq. km. only during the past 5 years.  Back in the 1980s, the area didn’t fall beneath 5 million sq. km. except for two years (1984, 1989).  This is simply another way of noting that the Arctic environment has changed substantially in the past generation.  One more note about the anomaly value (-2.157 here): 2007’s lowest anomaly currently ranks as the modern-day record: -3.6 million sq. km.  2012’s anomaly value is obviously far away from that, but has spent the most time below -2 million sq. km. than any year except 2007.

Antarctic Pictures and Graphs

Here is a satellite representation of Antarctic sea ice conditions from July 7th:

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Figure 7UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20120707.

Compare that graphic with the same view from August 6th:

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Figure 8UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20120806.

Ice gain is less easily visible around the continent than it was a few months ago.  As a reminder, the difference between long-term Arctic ice loss and lack of Antarctic ice loss is largely and somewhat confusingly due to the ozone depletion that took place over the southern continent in the 20th century.  This depletion has caused a colder southern polar stratosphere than it otherwise would be, reinforcing the polar vortex over the Antarctic Circle.  That vortex has helped keep cold, stormy weather in place over Antarctica that might not otherwise would have occurred to the same extent and intensity.  As the “ozone hole” continues to recover during this century, the effects of global warming will become more clear in this region, especially if ocean warming continues to melt sea-based Antarctic ice from below.  For now, we should perhaps consider the lack of global warming signal due to lack of ozone as relatively fortunate.

Finally, here is the Antarctic sea ice extent time series from August 6th:

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Figure 9NSIDC Antarctic sea ice extent time series through early August 2012.

Antarctic sea ice extent had remained at or above average to some extent through the late austral fall and through the austral winter, which is good news.  The difference in conditions from the first part of 2011 to the similar time period in 2012 is obvious: NSIDC measured last July’s extent near the bottom of the standard deviation envelope while this year’s extent is much healthier.

Errata

Here are my State of the Poles posts from July and June.

You can find NSIDC’s August report here.

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