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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.

 photo GlobalTemperatureAnomalyMap201301_zps05956f2c.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.

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):

 photo NinoSSTAnom20130301_zps06ef6b19.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 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.

Photobucket

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.

 photo 201201-201212_zps7a320a03.gif

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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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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NASA & NOAA: June 2012 Was 4th Warmest On Record

According to data released by NASA and NOAA this week, June 2012 was the 4th warmest June globally on record.  NASA’s analysis produced the 4th warmest June in its dataset; NOAA recorded the 4th warmest May in its dataset.  The two agencies have slightly different analysis techniques, which actually helps to reinforce the results from each other.

The details:

June’s global average temperatures were 0.56°C (1.01°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 June 2012).  The past three months have a +0.59°C temperature anomaly.  And the latest 12-month period (Jul 2011 – Jun 2012) had a +0.52°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 normal, 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 June 2012 from NASA.

According to NOAA, June’s global average temperatures were 0.63°C (1.13°F) above the 20th century mean of 15.5°C (59.9°F).  NOAA’s global temperature anomaly map for June (duplicated below) reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.  Unfortunately in June 2012, almost the entire Northern Hemisphere was warmer than normal.

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

The extreme 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 earlier this month.  3.6°C may not sound that warm in July, but look at the station’s location:

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Figure 3. Location of Summit Camp, Greenland.

The station is in the middle of the massive Greenland ice sheet at ~10,500ft elevation.  It is difficult to warm this area enough to register above freezing temperatures.  Multiple stations on the top of the ice sheet similarly observed record warm temperatures recently.  What happens when air temperatures are above freezing with the mid-summer sun shining down for most of the day?  Record flooding occurs.

These observations are also worrisome for the following reason: the globe is still exiting the latest La Niña event:

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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).

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 toward a +0.5°C anomaly (y-axis).  La Niña is a cooling event of the tropical Pacific Ocean that has 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 this last La Niña had via this NASA time series.

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 predictions of ENSO conditions by various models (dynamical and statistical).  To be considered an El Niño event, 3-month temperature anomalies must be measured above +0.5°C for 5 consecutive months.  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.


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NASA & NOAA: May 2012 Was 2nd Warmest On Record

According to data released by NASA and NOAA this month, May 2012 was the 2nd warmest May on record: NASA’s analysis produced the 2nd (tied with 2010) warmest May in its dataset; NOAA recorded the 2nd warmest May in its dataset.  The two agencies have slightly different analysis techniques, which actually helps to reinforce the results from each other.

The details:

May’s global average temperatures were 0.65°C (1.17°F) above normal (1951-1980), according to NASA.  The warmest regions on Earth are exactly where climate models have been projecting the most warmth to occur for years: high latitudes (especially within the Arctic Circle in May 2012).  The past three months have a +0.56°C temperature anomaly.  And the latest 12-month period (Jun 2011 – May 2012) had a +0.52°C temperature anomaly.

According to NOAA, May’s global average temperatures were 0.66°C (1.19°F) above the 20th century mean of 14.8°C (58.6°F).  NOAA’s global temperature anomaly map for May (duplicated below) reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.  Unfortunately in May 2012, the Northern Hemisphere was almost entirely warmer than normal.  The extreme 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,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.

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Figure 1. Global temperature anomaly map for May 2012 from NOAA.

These observations are also worrisome for the following reason: the globe is still exiting the latest La Niña event:

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Figure 2. 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 in December 2011.  Since then, SSTs have slowly warmed back toward a 0C anomaly (y-axis).  La Niña is a cooling event of the tropical Pacific Ocean that has effects across the globe.  It is therefore significant that the past few 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 this last La Niña had via this NASA time series.

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).  Looking further into the future, what will next year’s temperatures be as the next El Niño develops?


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NASA & NOAA: April 2012 Among Top 5 Warmest On Record

According to data released by NASA and NOAA this month, April 2012 ranked among the top 5 warmest Aprils on record: NASA recorded the 4th (tied) warmest April in its dataset; NOAA recorded the 5th warmest April in its dataset.  The two agencies have slightly different analysis techniques, which actually helps to reinforce the results from each other.

The details:

April’s global average temperatures were 0.56°C above normal (1951-1980), according to NASA.  The warmest regions on Earth are exactly where climate models have been projecting the most warmth to occur for years: high latitudes (especially within the Arctic Circle in April 2012).  The past three months have a +0.47°C temperature anomaly.  And the latest 12-month period (May 2011 – Apr 2012) had a +0.49°C temperature anomaly.

According to NOAA, April’s global average temperatures were 0.65°C (1.17°F) above the 20th century mean of 13.7°C (56.7°F).  NOAA’s global temperature anomaly map for April reinforces the message: high latitudes continue to warm at a faster rate than the mid- or low-latitudes.  The extreme 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,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 the methane signal for many more years.

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