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Bridging climate science, citizens, and policy


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State of Polar Sea Ice – September 2014: Arctic Sea Ice Minimum and Antarctic Sea Maximum

Global polar sea ice area in September 2014 remained at or near climatological normal conditions (1979-2008).  This situation has held true since early 2013 – a clear departure from conditions during the past 10+ years.  Global sea ice area values consist of two components: Arctic and Antarctic sea ice.  Conditions are quite different between these two regions: there is abundant Antarctic sea ice while Arctic sea ice remained well below normal again during 2014.  I’ll discuss both regions below.

Arctic Sea Ice

According to the NSIDC, September 2014′s average extent was 5.28 million sq. km., a 1.24 million sq. km. below normal conditions.  This value is the minimum for 2014 as less sunlight and colder fall temperatures now allow for melting ice.  September 2014 sea ice extent continued a two-plus year-long trend of monthly mean below normal values.  The deficit from normal was different each month during that time due to weather conditions overlaying longer term climate signals.

Sea ice anomalies at the edge of the pack are of interest.  Laptev and East Siberian Sea ice, for instance, was lower than their respective normals this year while Beaufort Sea and Canadian Archipelago ice maintained higher ice extent this year than they did a few years ago.  Arctic Basin ice extent was lower than its normal, but higher than it was during the late-2000s.

September 2014 average sea ice extent was the sixth lowest in the satellite record (post-1979).  Figure 1 shows that the September linear rate of decline is 13.3% per decade (blue line) relative to the 1981 to 2012 mean, compared to 2.6% per decade decline for March through 2014.  Summer ice is more affected from climate change than winter ice.  Of note, the trend through September 2013 was 13.7%, so this year’s minimum, while historically significant, was not as bad as it was during recent years.

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Figure 1 – Mean Sea Ice Extent for September: 1979-2014 [NSIDC].

Arctic Pictures and Graphs

The following graphic is a satellite representation of Arctic ice as of April 1st, 2014:

 photo Arctic_sea_ice_20140401_zpsdd9dbc04.png

Figure 2 UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20140401.

Compare that with the following graphic – a satellite representation of Arctic ice as of October 7th, 2014:

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Figure 3UIUC Polar Research Group‘s Northern Hemispheric ice concentration (color contours) from 20141007.  Recent snowfall is indicated by gray-scheme contours over land.

As described above, the 2014 melt season ended with the sixth lowest Arctic sea ice extent during the satellite era.  Approximately 10 million sq. km. of sea ice  melted again this year.  That isn’t a record (11.5 million sq. km. melted in 2012), but that is a lot of melted ice.

Of greater importance is the overall health of the ice pack, which we can begin to ascertain by looking at the volume of ice, as in Figure 4:

 photo SeaIceVolumeAnomaly_20140930_zps48c8bf58.png

Figure 4PIOMAS Arctic sea ice volume time series through September 2014.

This graph shows something unique: a recent resurgence of ice volume anomalies during the past 2-3 years.  You can see that in 2011 and 2012, Arctic sea ice volume reached values below the 2nd standard deviation from normal – near -7000 and -8000 km^3.  2013 looked a bit better and 2014 looks better still: volume anomalies are back above the long-term trend line.  While that isn’t enough to declare no problems exist in the Arctic, the situation certainly is different from it was just a couple of years ago.  Put another way, these graphics show something quite different from the strident proclamations of doom from climate activists in early 2013 when holes and cracks were seen earlier than normal on Arctic sea ice.  At the time, they wondered (too loudly at times) whether an ice-free summer was in our immediate future.  I cautioned against such radical conclusions at the time and continue to do so now.  While not healthy, Arctic sea ice isn’t in as bad a shape as some wanted to believe.

Arctic Sea Ice Extent

Take a look at September’s areal extent time series data:

 photo N_stddev_timeseries_20141001_1_zpsa497f1ad.png

Figure 5NSIDC Arctic sea ice extent time series through early Ocrtober 2014 (light blue line) compared with four recent years’ data, climatological norm (dark gray line) and +/-2 standard deviation envelope (light gray).

This figure puts 2014 into context against other recent winters.  As you can see, Arctic sea ice extent was at or below the bottom of the negative 2nd standard deviation from the 1981-2012 mean during each of the past five years.  The 2nd standard deviation envelope covers 95% of all observations.  That means the past five years’ ice extents were extremely low compared to climatology.  Thankfully, 2014 sea ice extent did not set another all-time record.  This year’s values were within the 2nd standard deviation envelope and look similar to 2013’s.

Antarctic Pictures and Graphs

Here is a satellite representation of Antarctic sea ice conditions from April 2nd, 2014:

 photo Antarctic_sea_ice_20140401_zpsd15f0ddf.png

Figure 6UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20140402.

And here is the corresponding figure from October 7th, 2014:

 photo Antarctic_sea_ice_20141007_zps57847a53.png

Figure 7UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20141007.

Here we see evidence that the Antarctic is quite different from the Arctic.  Instead of record minimums, Antarctic sea ice is recording record maximums.  The April graphic begins the story: the Antarctic sea ice minimum value this year was quite high, so ice started from a different (higher) point than in recent decades.  This new pattern evolved during the past few years and absent additional changes is likely to continue for the foreseeable future.  With a head-start on ice extent, mid-winter ice grew to the largest extent on record: 20.03 million sq. km., 1.24 million sq. km. above the 1981 to 2010 average for September ice extent.

Figure 8 shows this situation in time series form:

 photo S_stddev_timeseries_20141001_zps52351c47.png

Figure 8NSIDC Antarctic sea ice extent time series through early October 2014.

The big surge in extent in late September is all the more impressive because it set another all-time record for extent, as also happened in 2012 and 2013, as Figure 9 shows:

 photo Antarctic_monthly_sea_ice_extent_201409_zps735c9cd0.png

Figure 9 – Mean Antarctic Sea Ice Extent for September: 1979-2014 [NSIDC].

You’re eyes aren’t deceiving you: the Antarctic September sea ice extent trend is opposite that of the Arctic sea ice extent trend.  The Antarctic trend is +1.3%/decade.  The reason for this seeming discrepancy is rooted in atmospheric chemistry and dynamics (how and why the atmosphere moves the way it does) and ice dynamics.  A reasonable person without polar expertise likely looks at Figures 1 and 9 and says, “I don’t see evidence of catastrophe here.   I see something bad in one place and something good in another place.”  For people without the time or inclination to invest in the layered nuances of climate, most activists come off sounding out of touch when they always preach gloom and doom.  If climate change really were as clearly devastating as activists screamed it was, wouldn’t it be obvious in all these pictures and plots?  Or, as I’ve commented at other places recently, do you really think people who are insecure about their jobs and savings even have the time for this kind of information?

Policy

Given the lack of climate policy development at a national or international level to date, Arctic conditions will likely continue to deteriorate for the foreseeable future.  This is especially true when you consider that climate effects today are largely due to greenhouse gas concentrations from 30 years ago.  It takes a long time for the additional radiative forcing to make its way through the entire climate system.  The Arctic Ocean will soak up additional energy (heat) from the Sun due to lack of reflective sea ice each summer.  Additional energy in the climate system creates cascading and nonlinear effects throughout the system.  For instance, excess energy can push the Arctic Oscillation to a more negative phase, which allows anomalously cold air to pour south over Northern Hemisphere land masses while warm air moves over the Arctic during the winter.  This in turn impacts weather patterns throughout the year (witness winter 2013-14 weather stories) across the mid-latitudes and prevents rapid ice growth where we want it.

More worrisome for the long-term is the heat that impacts land-based ice.  As glaciers and ice sheets melt, sea-level rise occurs.  Beyond the increasing rate of sea-level rise due to thermal expansion (excess energy, see above), storms have more water to push onshore as they move along coastlines.  We can continue to react to these developments as we’ve mostly done so far and allocate billions of dollars in relief funds because of all the human infrastructure lining our coasts.  Or we can be proactive, minimize future global effects, and reduce societal costs.  The choice remains ours.

Errata

Here are my State of Polar Sea Ice posts from April 2014 and October 2013.


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Climate and Energy Links – Jul 2014

Some things I’ve come across recently:
New mega-map details all the ways climate change will affect our everyday lives.  We’ll need more resources like this to help personalize climate change effects.  With personalization will come motivation to act.  It’s not a panacea, but a good start.

Is your state one of the 10 most energy-efficient US states?  Mine (Colorado) isn’t.  More context: the US is good at buzzwords, but lousy at implementing policies that increase energy efficiency.  Although it’s a good thing that China is currently ranked #4 globally – they’ll have much less legacy infrastructure than the US and other developed nations to upgrade in the future.

This might be news to some: climate models that did the best at portraying natural ocean cycles the best also did better than their peers when projecting the recent surface warming pause.  What most people don’t understand is that each climate model run portrays one individual potential outcome.  That said, scientists don’t claim that individual models make perfect predictions.  The recent warming trend is well within the range of available projections.  Many skeptics, of course, gloss over this important detail when they falsely claim the models are no good.  How much time do those same skeptics spend on financial projections, anyway?

This has the potential for misinterpretation and misuse: climate worriers don’t, on average, use less electricity than those who don’t worry about the climate (at least according to a very small UK study).  They use more.  This will continue the claims of hypocrisy by skeptics, and perhaps justifiably so.  My net utility use is 14% to 17% of the average American’s 903 kilowatthours (kWh) per month: 125-150 kWh per month during the past year.  That’s in a modern home with AC, computers, and smartphones.  People can use much less than they currently do with a modern lifestyle.  They just don’t prioritize it.

Continuing on the theme of energy efficiency and waste: we waste 80 billion USD per year due to inefficient electronic devices.  Wow.   And it doesn’t have to be that way: simple measures could save billions of dollars if we implemented them.  Priorities.

Random thought: poverty-wage employers always ask if people would be willing to pay more for products if they paid their employees living wages.  I haven’t come across an easy rebuttal: were customers asked if they were willing to pay more for products if they paid their executives millions of dollars with guaranteed golden parachutes?  Guess what most people would rather support?  That’s right, the folks in their communities, not executives in their fenced off country club homes.


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On False Equivalence

The Guardian recently ran a couple of really bad climate pieces.  The first has a headline guaranteed to draw eyes, “Miami, the great world city, is drowning while the powers that be look away“.  Who would possibly allow a “great world city” drown?  The monsters!  Know that the author is billed as a “science editor”, which I take to mean he understands basic scientific concepts such as uncertainty, time scale, and accuracy.  What does Robin McKie have to say?

The effect is calamitous. Shops and houses are inundated; city life is paralysed; cars are ruined by the corrosive seawater that immerses them. [...] Only those on higher floors can hope to protect their cars from surging sea waters that corrode and rot the innards of their vehicles. [...] Miami and its surroundings are facing a calamity worthy of the Old Testament.

Really?  Old Testament calamity? Inundated. Paralysed. Ruined. Corrode and rot.

That’s fairly flowery language for a science editor.  How much of it is based in reality?  There are definitely localized effects of sea level rise in Miami.  Seawater is corrosive.  But I missed the news reports of Miami calamities, inundations, being a paralyzed city.  Those are serious effects he describes that aren’t quite as extensive or horrific as his article portrays.

Or, as Time writer Michael Grunwald writes, “I’m sorry to spoil the climate porn, but while the periodic puddles in my Whole Foods parking lot are harbingers of a potentially catastrophic future, they are not currently catastrophic. They are annoying. And so is this kind of yellow climate journalism.”

I agree with Michael on this one.  This type of journalism works against taking the very action that Miami actually is doing right now to adapt to a changing reality.  This quote says it perfectly:

What’s happening in the Middle East right now is calamitous. A blocked entrance is inconvenient.

Thank you, Michael, for some overdue perspective.  He adds,

But let’s get real. The Pacific island of Kiribati is drowning; Miami Beach is not yet drowning, and the Guardian’s persistent adjective inflation (“calamitous,” “astonishing,” “devastating”) can’t change that.

This encouraged a number of climate porn addicts to take to the Twitter and denounce Grunwald’s lack of enthusiasm for not wanting to be a part of their tribe.  Tweets displayed peoples’ camps:

Here is what folks were trying to say: person A has a gun held to their head right now; person B will die sometime in the future, but we don’t know exactly when.  And since the same characteristic will eventually apply to both persons, they both share existential threats.  Ask Kiribatians how much of their daily life is affected by sea level rise and I’d bet dollars to doughnuts you’ll get a very different answer than a Miamians’.  And contrary to most climate activists, that’s not because Miamians are climate uneducated.  It’s because their daily lives aren’t affected by climate change today to the same degree than a Kiribatian is.  Saying they are doesn’t make it so.

I also agree with Mike that this fact doesn’t alter the need to mitigate and adapt.  I agree with TheCostofEnergy that Miami and island nations face different timing and resource issues.  That is precisely why island nations face an existential threat today and Miami doesn’t.  Island nation people have nowhere to move to.  Their islands will disappear and they will be forced to move.  That presents an enormous culture disruption.  Miami has much more adaptive capacity than do island nations.  Miami will have to adapt, there is no doubt about that.  But that’s not an existential threat except in some absurdly narrow use of the term.

Disaster porn language usage has to stop.  It’s not accurate.  It dissuades instead of incentivizes action.  It breaks down instead of builds trust.


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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.

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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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State of Polar Sea Ice – March 2014: Arctic Sea Ice Maximum and Antarctic Sea Minimum

Global polar sea ice area in March 2014 remained at or near climatological normal conditions (1979-2008).  This represents early 2013 conditions continuing to present when sea ice area was at or above the average daily value.  Global sea ice area values consist of two components: Arctic and Antarctic sea ice.  Conditions are quite different between these two regions: Antarctic sea ice continues to exist abundantly while Arctic sea ice remained well below normal again during the past five months.

The NSIDC made a very important change to its dataset in June.  With more than 30 years’ worth of satellite-era data, they recalculated climatological normals to agree with World Meteorological Organization standards.  The new climatological era runs from 1981-2010 (see Figure 6 below).  What impacts did this have on their data?  The means and standard deviations now encompass the time period of fastest Arctic melt.  As a consequence, the 1981-2010 values are much lower than the 1979-2000 values.  This is often one of the most challenging conditions to explain to the public.  “Normal”, scientifically defined, is often different from “normal” as most people refer to it.  U.S. temperature anomalies reported in the past couple of years refer to a similar 1981-2010 “normal period”.  Those anomalies are smaller in value than if we compared them to the previous 1971-2000 “normal period”.  Thus, temperature anomalies don’t seem to increase as much as they would if scientists referred to the same reference period.

Arctic Sea Ice

According to the NSIDC, March 2014′s average extent was 14.80 million sq. km., a 730,000 sq. km. difference from normal conditions.  This value is the maximum for 2014 as more sunlight and warmer spring temperatures now allow for melting ice.  March 2014 sea ice extent continued a nearly two-year long trend of below normal values.  The deficit from normal was different each month during that time due to weather conditions overlaying longer term climate signals.  Arctic sea ice extent could increase during the next month or so depending on specific wind conditions, but as I wrote above, we likely witnessed 2014’s maximum Arctic sea ice extent 10 or so days ago.

Sea ice anomalies at the edge of the pack are of interest.  There is slightly more ice than normal in the St. Lawrence and Newfounland Seas on the Atlantic side of the pack.  Barents sea ice area, meanwhile, is slightly below normal.  Bering Sea ice recently returned to normal from below normal, while Sea of Okhotsk sea ice remains below normal.  The ice in these seas will melt first since they are on the edge of the ice pack and are the thinnest since they just formed in the last month.

March average sea ice extent for 2014 was the fifth lowest in the satellite record.  The March linear rate of decline is 2.6% per decade relative to the 1981 to 2012 average, as Figure 1 shows (compared to 13.7% per decade decline for September: summer ice is more affected from climate change than winter ice).  Figure 1 also shows that March 2014′s mean extent ranked fifth lowest on record.

 photo Arctic_monthly_sea_ice_extent_201403_zpsf13de46a.png

Figure 1 – Mean Sea Ice Extent for March: 1979-2014 [NSIDC].

Arctic Pictures and Graphs

The following graphic is a satellite representation of Arctic ice as of October 1st, 2013:

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Figure 2UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20131001.

The following graphic is a satellite representation of Arctic ice as of January 15th, 2014:

 photo Arctic_sea_ice_20140115_zps96036b51.png

Figure 3UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20140115.

The following graphic is a satellite representation of Arctic ice as of April 1st, 2014:

 photo Arctic_sea_ice_20140401_zpsdd9dbc04.png

Figure 4 UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20140401.

I captured Figure 2 right after 2013’s date of minimum ice extent occurrence.  I wasn’t able to put together a post in January on polar sea ice, but captured Figure 3 for future reference.  You can see the rapid growth of ice area and extent in three month’s time.  Since January, additional sea ice formed, but not nearly as much as during the previous three months.  Figure 4 shows conditions just after the annual maximum sea ice area occurred.  From this point through late September, the overall trend will be melting ice – from the edge inward.

The following graph of Arctic ice volume from the end of January (PIOMAS updates are not available from the end of February or March) demonstrates the relative decline in ice health with time:

 photo SeaIceVolumeAnomaly_20140131_zpse02b6133.png

Figure 5PIOMAS Arctic sea ice volume time series through January 2014.

The blue line is the linear trend, identified as -3,000 km^3 (+/- 1,000 km^3) per decade.  In 1980, there was a +5,000 km^3 anomaly compared to 2013’s -6,000 km^3 anomaly – a difference of 11,000 km^3.  How much ice is that?  That volume of ice is equivalent to the volume in Lake Superior!

Arctic Sea Ice Extent

Take a look at March’s areal extent time series data:

 photo N_stddev_timeseries_20140401_1_zps069b9c1d.png

Figure 6NSIDC Arctic sea ice extent time series through early April 2014 (light blue line) compared with four recent years’ data, climatological norm (dark gray line) and +/-2 standard deviation envelope (light gray).

This figure puts winter 2013-14 into context against other recent winters.  As you can see, Arctic sea ice extent was at or below the bottom of the negative 2nd standard deviation from the 1981-2012 mean.  The 2nd standard deviation envelope covers 95% of all observations.  That means the past five winters were extremely low compared to climatology.  With the maximum ice extent in mid-March, 2014’s extent now hovers near record lows for the date.  Previous winters saw a late-season ice formation surge caused by specific weather patterns.  Those patterns are not likely to increase sea ice extent this boreal spring.  This doesn’t mean much at all for projections of minimum sea ice extent values, as the NSIDC discusses in this month’s report.

Antarctic Pictures and Graphs

Here is a satellite representation of Antarctic sea ice conditions from October 1, 2013:

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Figure 7UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20131001.

And here is the corresponding graphic from January 15th, 2014:

 photo Antarctic_sea_ice_20140115_zpsd2a383a2.png

Figure 8UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20140115.

The following graphic is a satellite representation of Antarctic ice as of April 2nd, 2014:

 photo Antarctic_sea_ice_20140401_zpsd15f0ddf.png

Figure 9UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20140402.

Antarctic sea ice clearly hit its minimum between mid-January and early April.  In fact, that date was likely six weeks ago.  Antarctic sea ice is forming again as austral fall is underway.  As in recent austral summers, the lack of sea ice around some locations in Figure 8 is related to melting land-based ice.  Likewise,  sea ice presence around other locations is a good indication that there is less land-based ice melt.  Figure 8 looks different from other January’s prior to 2012 and 2013.  Additionally, Antarctic weather in recent summers differed from previous years in that winds blew land-based ice onto the sea, especially east of the Antarctic Peninsula (jutting up towards South America), which replenished the sea ice that did melt.  The net effect of the these and other processes kept Antarctic sea ice at or above the 1979-2008 climatology’s positive 2nd standard deviation, as Figure 10 below shows.

Finally, here is the Antarctic sea ice extent time series through early April:

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Figure 10NSIDC Antarctic sea ice extent time series through early April 2014.

The fact that Arctic ice extent continues well below average while Antarctic ice extent continues well above average for the past couple of years works against climate activists who claim climate change is nothing but disaster and catastrophe.  A reasonable person without polar expertise likely looks at Figures 6 and 10 and says, “I don’t see evidence of catastrophe here.   I see something bad in one place and something good in another place.”  For people without the time or inclination to invest in the layered nuances of climate, most activists come off sounding out of touch.  If climate change really were as clearly devastating as activists screamed it was, wouldn’t it be obvious in all these pictures and plots?  Or, as I’ve commented at other places recently, do you really think people who are insecure about their jobs and savings even have the time for this kind of information?  I don’t have one family member or friend that regularly questions me about the state of the climate, despite knowing that’s what I research and keep tabs on.  Well actually, I do have one family member, but he is also a researcher and works in supercomputing.  Neither he nor I are what most people would consider “average Joes” on this topic.

Policy

Given the lack of climate policy development at a national or international level to date, Arctic conditions will likely continue to deteriorate for the foreseeable future.  This is especially true when you consider that climate effects today are largely due to greenhouse gas concentrations from 30 years ago.  It takes a long time for the additional radiative forcing to make its way through the entire climate system.  The Arctic Ocean will soak up additional energy (heat) from the Sun due to lack of reflective sea ice each summer.  Additional energy in the climate system creates cascading and nonlinear effects throughout the system.  For instance, excess energy pushes the Arctic Oscillation to a more negative phase, which allows anomalously cold air to pour south over Northern Hemisphere land masses while warm air moves over the Arctic during the winter.  This in turn impacts weather patterns throughout the year (witness winter 2013-14 weather stories) across the mid-latitudes and prevents rapid ice growth where we want it.

More worrisome for the long-term is the heat that impacts land-based ice.  As glaciers and ice sheets melt, sea-level rise occurs.  Beyond the increasing rate of sea-level rise due to thermal expansion (excess energy, see above), storms have more water to push onshore as they move along coastlines.  We can continue to react to these developments as we’ve mostly done so far and allocate billions of dollars in relief funds because of all the human infrastructure lining our coasts.  Or we can be proactive, minimize future global effects, and reduce societal costs.  The choice remains ours.

Errata

Here are my State of Polar Sea Ice posts from October and July 2013. For further comparison, here is my State of Polar Sea Ice post from late March 2013.


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State of Polar Sea Ice – September 2013: Arctic Sea Ice Minimum and Antarctic Sea Maximum

Global polar sea ice area in September 2013 was slightly below climatological normal conditions (1979-2008).  This represents a change from early 2013 conditions when sea ice area was at or above the average daily value.  Antarctic sea ice continues to exist abundantly while Arctic sea ice fell below normal again during the month.

The NSIDC made a very important change to its dataset in June.  With more than 30 years’ worth of satellite-era data, they recalculated climatological normals to agree with World Meteorological Organization standards.  The new climatological era runs from 1981-2010 (see Figure 6 below).  What impacts did this have on their data?  The means and standard deviations now encompass the time period of fastest Arctic melt.  As a consequence, the 1981-2010 values are much lower than the 1979-2000 values.  This is often one of the most challenging conditions to explain to the public.  “Normal”, scientifically defined, is often different than “normal” as most people refer to it.  U.S. temperature anomalies reported in the past couple of years refer to a similar 1981-2010 “normal period”.  Those anomalies are smaller in value than if we compared them to the previous 1971-2000 “normal period”.  Thus, temperature anomalies don’t seem to increase as much as they would if scientists referred to the same reference period.

Arctic Sea Ice

According to the NSIDC, September 2013′s average extent was only 5.35 million sq. km., a 1.17 million sq. km. difference from normal conditions.  This value is the minimum for 2013 as less sunlight and cooler autumn temperatures now allow for ice to refreeze.  September 2013 sea ice extent was 1.72 million square kilometers higher than the previous record low for the month that occurred in 2012.  The shift from a record low value one  year to a non-record low the next is completely normal.  Indeed, had Arctic sea ice extent fallen to a new record low, conditions this year would have been much more inhospitable to sea ice than they were.  To be clear, I do not cheer new record lows.  They are worthy of discussion not simply because of the record they set, but because they are part of a larger ongoing trend.  This year’s minimum extent value did not break that trend, it continued it.

Overall, conditions across the Arctic Ocean this summer prevented record-setting ice loss.  There were more clouds in 2013 than 2012.  Clouds reflect most incoming solar radiation, which means less sea ice melts.  At the end of the melt season, many small seas had normal sea ice extent, which is to say none.  Anomalous areas include the East Siberian Sea and the Arctic Basin, which recorded less sea ice extent than normal.

September average sea ice extent for 2013 was the sixth lowest in the satellite record. The 2012 September extent was 32% lower than this year’s extent.  The September linear rate of decline is 13.7% per decade relative to the 1981 to 2010 average, as Figure 1 shows.  Figure 1 also shows that September 2013’s mean extent ranked sixth lowest on record.  You can see from the graph that although a new record minimum was not set in 2013, the negative multi-year trend continued.

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Figure 1 – Mean Sea Ice Extent for Septembers: 1979-2013 [NSIDC].

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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.

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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.

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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.

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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.  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).

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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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