Weatherdem's Weblog

Bridging climate science, citizens, and policy


4 Comments

55.7% of the Contiguous United States in Moderate or Worse Drought – 12 Feb 2013

According to the Drought Monitor, drought conditions are relatively unchanged in the past two weeks. As of Feb. 12, 2013, 55.7% of the contiguous US is experiencing moderate or worse drought (D1-D4). The percentage area experiencing extreme to exceptional drought increased from 19.4% to 17.7% in the last two weeks. Percentage areas experiencing drought across the West stayed mostly the same while snowpack increased. Drought across the Southwest decreased slightly. Meanwhile, storms improved drought conditions in the Southeast.

This post precedes a significant snow event across the High and Great Plains.  The NWS expects up to a foot of snow in some areas of the Plains over the next couple of days, which will provide about 1″ of liquid water equivalent.  Since these areas currently suffer from a 2-4″ liquid water deficit, this storm will not break the short-term drought.  Moreover, long-term drought will only be broken by substantial spring and summer rainfall.  After one or two more Drought Monitor updates, we should see some welcome differences in these maps.

 photo USDrought20130212_zps5127c8cb.gif

Figure 1 – US Drought Monitor map of drought conditions as of the 12th of February.

 photo west_drought_monitor_20130212_zps091887be.png

Figure 2 – US Drought Monitor map of drought conditions in Western US as of the 12th of February.  Some small relief is evident in the past week, including some changes in the mountains as storms recently dumped snow across the region.  Mountainous areas and river basins will have to wait until spring for snowmelt to significantly alleviate drought conditions.

 photo CO_drought_monitor_20130212_zpsf4ce66ed.png

Figure 3 – US Drought Monitor map of drought conditions in Colorado as of the 12th of February.  Drought conditions held mostly steady across the state in the past week.  For the first time in over a month, less than 100% of CO is experiencing Severe drought conditions.  This improvement occurred over the southwestern portion of the state due to mid-season snow storms.  Unfortunately, Exceptional drought conditions expanded over the northeastern plains.

 photo southeast_drought_monitor_20130212_zps1ed01004.png

Figure 4 – US Drought Monitor map of drought conditions in Southeast US as of the 12th of February.  As mentioned above, drought conditions contracted a little and grew less severe in the past couple of weeks.  The worst hit area, in central Georgia, has experienced the longest duration drought conditions on this map.

Cooler than normal sea-surface temperatures (SSTs) are present in the eastern Pacific, according to current MJO and ENSO data.  Additionally, eastern Pacific SSTs are cooler than the climatic average due to the current negative phase of the IPO.  This in turn is due in part to global warming, which is causing warmer western Pacific and Indian Ocean SSTs than usual.  The cool SSTs in the eastern Pacific initiate and reinforce air circulations that generally keep precipitation away from the Southwest and Midwest US.  This doesn’t mean that drought will be ever-present; only that we are potentially forcing the climate system toward more frequent drought conditions in these regions.  Some years will still be wet or normal; other years (increasing in number) will be dry.  This counters skeptics who claim that more CO2 and warmer temperatures are better for plants.  If there is no precipitation, plants cannot take advantage of longer growing seasons.  Moreover, we will experience years with increased food pressure.  These conditions’ extent in the future is up to us and our climate policy (or lack thereof).

While MJO, ENSO, and IPO are all in phases that tend to deflect storm systems from the Southwest, this week’s storm demonstrates that the conditions are not ever-present.  Weather variability still occurs with the dryer regime.  Put another way, weather is not climate.


Leave a comment

57.7% of Contiguous US in Moderate or Worse Drought – 29 Jan 2013

According to the Drought Monitor, drought conditions are relatively unchanged in the past two weeks. As of Jan. 29, 2013, 57.7% of the contiguous US is experiencing moderate or worse drought (D0-D4). The percentage area experiencing extreme to exceptional drought increased from 19.3% to 19.4%. Percentage areas experiencing drought across the West stayed mostly the same at the end of January as they were at in the middle. Drought across the Southwest decreased slightly. Meanwhile, drought across the Southeast grew due to relative lack of precipitation.

 photo USDrought20130129_zps172b8c30.gif

Figure 1 – US Drought Monitor map of drought conditions as of the 29th of January.

 photo west_drought_monitor_20130129_zpscc61a026.png

Figure 2 – US Drought Monitor map of drought conditions in Western US as of the 29th of January.  Some small relief is evident in the past week, but note the lack of change of drought conditions across the regions, despite recent snows throughout the mountains.  Mountainous areas and river basins will have to wait until spring for snowmelt to help start to alleviate drought conditions.

 photo CO_drought_monitor_20130129_zpse63adfc2.png

Figure 3 – US Drought Monitor map of drought conditions in Colorado as of the 29th of January.  Drought conditions held steady across the state in the past week.  100% of Colorado experienced Severe or worse drought conditions for the past three weeks.

 photo southeast_drought_monitor_20130129_zps13685b05.png

Figure 4 – US Drought Monitor map of drought conditions in Southeast US as of the 29th of January.  As mentioned above, drought conditions expanded and worsened in the past couple of weeks.  The worst hit area, in central Georgia, has experienced the longest duration drought conditions on this map.  Drought has expanded and contracted around this area during that time.

The latest seasonal (three-month) outlook from the National Weather Service predicts enhanced chances for above-average temperature and below-average precipitation for the central US.  This means that drought conditions are likely to continue for at least another three months and probably longer if prevailing conditions do not change.  One of the major weather stories of 2012 was drought; 2013 is shaping up to have the same story.

What is causing this?  A combination of factors: the Arctic Oscillation (AO), the Madden-Julian Oscillation (MJO), the El-Nino and Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO), and background climate warming.

As I discussed in my last drought post:

The lack of sea ice in the Arctic back in September is part of what caused the negative phase of the AO.  The Arctic Ocean absorbed solar radiation instead of reflecting it back to space.  The ocean then slowly released that heat to the atmosphere before new ice could form.  That extra heat in the atmosphere changed how and where the polar jet stream established this winter.  Instead of a tight loop near the Arctic Circle, the jet stream has grown in North-South amplitude, allowing cold air to pour to latitudes more southerly than usual and warm air to move over northern latitudes.  The large amplitude jet has kept the normal type of storms from moving over locations that used to see them regularly during the winter.

An active MJO is keeping trade winds stronger than they otherwise would be, which piles up warm ocean water in the western tropical Pacific Ocean.  This causes cool, deep ocean water to rise in the eastern Pacific, as seen in Figure 5.

 photo MJO_20130202_zps7c1d39cf.gif

Figure 5Madden-Julian Oscillation conditions as of 2 Feb 2013 from NOAA-CPC.

 photo NinoSSTAnom20130204_zps674def05.gif

Figure 6ENSO conditions as of 2 Feb 2013 from NOAA-CPC.

Cooler than normal sea-surface temperatures (SSTs) are present in the eastern Pacific due to the current MJO and ENSO data.  Additionally, eastern Pacific SSTs are cooler than the climatic average due to the current negative phase of the IPO.  This in turn is due in part to global warming, which is causing western Pacific and Indian Ocean SSTs warmer than usual.  The cool SSTs in the eastern Pacific initiate and reinforce air circulations that generally keep precipitation away from the Southwest and Midwest US.  This doesn’t mean that drought will be ever-present; only that we are potentially forcing the climate system toward more frequent drought conditions in these regions.  Some years will still be wet or normal; other years (increasing in number) will be dry.  This is a counter to skeptics who claim that more CO2 and warmer temperatures are necessarily better for plants.  If there is no precipitation, plants cannot take advantage of longer growing seasons.  Moreover, we will experience years with food pressure.  These conditions’ extent in the future is up to us and our climate policy (or lack thereof).


1 Comment

58.9% of Contiguous US in Moderate or Worse Drought – 15 Jan 2013

The storm systems that moved over the US in the past month alleviated some of the drought conditions across the US, according to the Drought Monitor. As of Jan 15, 2013, 58.9% of the contiguous US is experiencing moderate or worse drought (D0-D4). The percentage area experiencing extreme to exceptional drought decreased from 21.3% to 19.4%. Percentage areas experiencing drought across the West stayed mostly the same in the middle of January as they were at the end of December. Drought across the High Plains expanded slightly during the same period. Meanwhile, drought across the Southeast and Midwest shrank due to the aforementioned storm systems.

 photo USDrought20130122_zpsd097af30.gif

Figure 1 – US Drought Monitor map of drought conditions as of the 15th of January.

 photo west_drought_monitor_20130115_zps0ec59e09.png

Figure 2 – US Drought Monitor map of drought conditions in Western US as of the 15th of January.  Note the lack of change of drought conditions across the regions, despite recent snows throughout the mountains.  Mountainous areas and river basins will have to wait until spring for snowmelt to help start to alleviate drought conditions.

 photo high_plains_drought_monitor_20130115_zps74706e61.png

Figure 3 – US Drought Monitor map of drought conditions in Midwest US as of the 15th of January.  This region also has not seen any meaningful shift in drought conditions recently.  The Plains will likely have to wait until spring and summer for drought relief.  This sector of the country does plant a significant amount of crops.  The winter wheat crop has already been devastated.

 photo CO_drought_monitor_20130122_zpsdf0e871b.png

Figure 4 – US Drought Monitor map of drought conditions in Colorado as of the 15th of January.  Drought conditions worsened slightly across the state in the past week.  Now, 100% of Colorado is experiencing Severe or worse drought conditions.  The percentage area with Extreme drought conditions is 5% higher than last week.  There was no significant difference in Exceptional drought area since last week.

 photo CO_drought_20120731.png

Figure 5 – US Drought Monitor map of drought conditions in Colorado as of July 31, 2012.  This figure shows how extensive the current drought is – both in space and time.  Severe or worse drought has afflicted close to 100% of the state for almost six months now.  While specific regions of the state have received some rain or snow, it hasn’t been enough to break the drought yet.  The percent area with Extreme or worse drought has decreased from 73.67% on July 24th to 65.35% on July 31st to 58.64% on January 15th.  The southeast part of the state has seen the worst of conditions, as Figure 5 and 6 demonstrate.

 photo CO_drought_monitor_20110614_zps5253e3a1.png

Figure 6 – US Drought Monitor map of drought conditions in Colorado as of June 14, 2011.  Eighteen months ago, more than half of Colorado was drought-free.  As you can see, the southeast part of the state has seen Severe or worse drought conditions for a long time now.

The US is not likely to see drought relief through March (drought predictions are accurate for ~3 months at a time) .  A negative Arctic Oscillation (AO; Figure 7) is challenging the return to ENSO-neutral conditions, which should allow normal precipitation to fall over the US.  The AO has been negative in previous winters and it has caused the severe winter storms that affected the northeastern US as well as UK (record wet year in 2012) and Scandinavia.

 photo Arctic_Oscillation_20130122_zps51fb4564.gif

Figure 7Arctic Oscillation time series from NOAA’s Climate Prediction Center.

The lack of sea ice in the Arctic back in September is part caused the negative phase of the AO.  The Arctic Ocean absorbed solar radiation instead of reflecting it back to space.  The ocean then slowly released that heat to the atmosphere before new ice could form.  That extra heat in the atmosphere changed how and where the polar jet stream established this winter.  Instead of a tight loop near the Arctic Circle, the jet stream has grown in N/S amplitude, allowing cold air to pour to latitudes more southerly than usual and warm air to move over northern latitudes.  The large amplitude jet has kept the normal type of storms from moving over locations that used to see them regularly during the winter.

Hence, the drought we see now over the US is causally linked to the Arctic Oscillation as well as the long-lasting, moderate La Niña (2010-2012).  Both of the natural variations exist on top of the background climate, which we are warming (this is why there was record low Arctic sea ice in 2012).  We will continue to see the climate modulate normal weather conditions until we stop emitting greenhouse gases.  As I’ve written, that isn’t likely to happen any decade soon.


5 Comments

How the IPCC Underestimated Climate Change – Scientific American article

Scientific American published an article summarizing what I’ve written about for a couple of years: the IPCC’s projections aren’t 100% correct.  Gasp – the horror!  But, contrary to what skeptics think, the direction the IPCC’s reports were wrong are opposite of what they claim.  The projections time and again underestimated future changes.  I think a valid complaint, and one I’ve made many times myself, is that the IPCC process is too conservative – it takes too long to get the kind of consensus they’re looking for.  Rapidly changing conditions are not well handled by the IPCC process.  When there is conflicting evidence of something, the IPCC has tended to say nothing in an effort not to upset anybody.  The good news is there are indications this is changing.  The list:

1. Emissions

This is the biggest one.  Too many studies focused on moderate emission pathways, when yearly updates showed our actual emissions were on the high range of those considered by the IPCC.  I actually posted on this two days ago: CO2 Emissions Continue to Track At Top of IPCC Range.  This has implications for every other process that follows.

2. Temperature

More accurately, energy in the climate system is the variable of interest.  It is easy to point out that temperatures since 2000 haven’t increased as much as projected.  It is also easy to compare observed trends since 1980 and claim AR4 models over-predicted temperature rise.  This conflates a couple of issues: the AR4 wasn’t used to project since 1980.  More importantly, the difference between observed trends since 1980 and projected temperatures from half of the AR4 models was less than 0.04°C (0.072°F).  That’s pretty darned small.  With respect to the trend since 2000, the real issue is energy gain.  The vast majority of energy has accumulated in the oceans:

Photobucket

More specifically, if the heat is transported quickly to the deep ocean (>2000ft), the sea surface temperature doesn’t increase rapidly.  Nor does atmosphere or land temperatures change.  This is true at least in the short-term.  When the ocean transports this heat from the deep back to the surface, we should be able to more easily measure that heat.  Put simply, the temporary hiatus of temperature rise is just that: temporary.  Are we prepared for when that hiatus ends?

The relatively small increase in near-surface air and land temperatures is thus explained.  The IPCC never claimed the 4.3° to 11.5°F temperature rise (AR4 projection) would happen by 2020 – it is likely to happen by 2100.  Expect more synergy between projected temperatures and observed temperatures in the coming years.  Also remember that climate is made up of long-term weather observations.

Additionally, aerosols emitted by developing nations have been observed to reflect some of the incoming solar radiation back to space.  Once these aerosols precipitate out of the atmosphere or are not emitted at some point in the future, the absorption of longwave radiation by the remaining greenhouse gases will be more prominent.  The higher the concentration of gases, the more radiation will be absorbed and the faster the future temperature rise is likely to be.  These aerosols are thus masking the signal that would otherwise be measured if they weren’t present.

3. Arctic Meltdown

This is the big story of 2012.  The Arctic sea ice melted in summer 2012 to a new record low: an area the size of the United States melted this year!  Even as late as 2007 (prior to the previous record-low melt), the IPCC projected that Arctic ice wouldn’t decrease much until at least 2050.  Instead, we’re decades ahead of this projection – despite only a relatively small global temperature increase in the past 25 years (0.15°C or so).  What will happen when temperatures increase by multiple degrees Centigrade?

4. Ice sheets

These are the land-based sheets, which are melting up to 100 years faster than the IPCC’s first three reports.  2007′s report was the first to identify more rapid ice sheet melt.  The problem is complex cryospheric dynamics.  Understandably, the most remote and inhospitable regions on Earth are the least studied.  Duh.  That’s changing, with efforts like the fourth International Polar Year, the results of which are still being studied and published.  Needless to say, modern instrumentation and larger field campaigns have resulted in advances in polar knowledge.

5. Sea Level Rise

It’s nice being relevant.  I just posted something new on this yesterday: NOAA Sea-Level Rise Report Issued – Dec 2012.  The 3.3mm of sea-level rise per year is higher than the 2001 report’s projection of 2mm per year.  Integrated over 100 years, that 1mm difference results in 4″ more SLR.  But again, with emission and energy underestimates, the 3.3mm rate of SLR is expected to increase in future decades, according to the latest research.  Again, another mm per year results in another 4″ 100 years from now.  Factors affecting SLR that the IPCC didn’t address in 2007 includes global ocean warming (warmer water takes up more volume), faster ice sheet melt, and faster glacial melt.  Additionally, feedback mechanisms are still poorly understood and therefore not well represented in today’s state-of-the-art models.

6. Ocean Acidification

The first 3 IPCC reports didn’t even mention this effect.  In the past 250 years, ocean acidity has increased by 30% – not a trivial amount!  As the article points out, research on this didn’t even start until after 2000.

7. Thawing Tundra

Another area that is not well-studied and therefore not well understood.  The mechanics and processes need to be observed so they can be modeled more effectively.  1.5 trillion tons of carbon are locked away in the currently frozen tundra.  If these regions thaw, as is likely since the Arctic has observed the most warming to date, methane could be released to the atmosphere.  Since methane acts as a more efficient GHG over short time frames, this could accelerate short-term warming much more quickly than projected (See temperatures above).  The SciAm article points out the AR5, to be released next year, will once again not include projections on this topic.

8. Tipping Points

This is probably the most controversial aspect of this list.  Put simply, no one knows where potential tipping points exist, if they do at all.  The only way we’re likely to find out about tipping points is by looking in the past some day in the future.  By then, of course, moving back to other side of the tipping point will be all but impossible on any time-frame relevant to people alive then.

Summary

There are plenty of problems with the UNFCCC’s IPCC process.  Underestimation of critical variables is but one problem plaguing it.  Blame it on scientists who, by training, are very conservative in their projections and language.  They also didn’t think policymakers would fail to curtail greenhouse gas emissions.  Do policymakers relying on the IPCC projections know of and/or understand this nuance?  If not, how robust will their decisions be?  The IPCC process needs to be more transparent, including allowing more viewpoints to be expressed, say in an Appendix compendium.  The risks associated with underestimating future change are higher than the opposite.


Leave a comment

Short Arctic Sea Ice Update – 20120723

Here, in a sneak peak of my monthly `State of the Poles` post, I wanted to mark a significant event: the area of Arctic sea ice has fallen below the climatological minimum.  This occurs with ~6 weeks left in the Arctic melt season.  In similar fashion as in other recent years, UIUC data show Arctic sea ice area values at a stunning -2 million sq. km. below the average value for this date in time.  Instead of 6.5 million sq. km., today’s value is 4.5 million sq. km., the record lowest for this calendar day.  Conditions on the Pacific side of the Arctic sea ice pack (another graphic here) are starting to deteriorate, so rapid melt of additional hundreds of thousands of sq. km. of sea ice could occur in the next month or so.  The recorded history yearly minimum sea ice area is ~2.91 million sq. km.  Stay tuned for this year’s minimum, which will likely occur in early September.


1 Comment

Research: Observations Decisively Indicate External Forcing Cause of Arctic Sea Ice Loss

It unfortunately takes a little bit of time, but climate skeptics’ claims that observations don’t support climate model projections aren’t supported as more observations are made of the Earth system.  The latest instance: instead of using just climate projections, a pair of researchers have used observations to try to determine whether internal variability (natural year-to-year changes), self-acceleration (positive feedback loops), or external forcing were most the likely drivers of observed sea-ice retreat in the past 30 years.

The takeaway from this research: external forcing (CO2) is shown to be most responsible.  This is a good case of how science works: investigate multiple potential causal factors and let the observed data speak for themselves.

The captions for the figures below come directly from the paper.

Photobucket

Figure 1. Evolution of Arctic sea-ice extent in (a) March and (c) September and the year-to-year changes in (b) March and (d) September. For this figure, an offset of +0.35 106 km2 in September and of 0.16  106 km2 in March has
been added to the entire original NSIDC dataset [Fetterer et al., 2002, 2010] to make the time series consistent with the original HadISST satellite time series during the period 1979–1996 [Met Office Hadley Centre, 2006].

The investigation included 60 years of robust sea ice data – from HadISST as well as NSIDC.  They used NSIDC in the satellite era because it provides a more consistent interpretation of the period.  As you can see, conditions in the Arctic started changing in the 1980s.  By 2000, both March and September conditions were different than conditions in the middle of the 20th century.  One big question when looking at this or similar time series data is whether the recent decline in sea ice is natural or not.  The following figure helps to answer that question quite definitively:

Photobucket

Figure 2 [4 in paper]. Relationship between sea-ice evolution and various forcings. (a) Temporal evolution of solar irradiance [Fröhlich, 2000], AO-index [Thompson and Wallace, 1998], PDOindex [Mantua and Hare, 2002], and CO2 concentration (scaling with a 1.66 W/m2 equivalence for a 100 ppm increase [Intergovernmental Panel on Climate Change, 2007]). The thin lines denote monthly values, while thick lines denote averages over 1 year (CO2), 5 years (AO-index, PDO-index) and 10 years (solar irradiance). (b–e) September sea ice extent from 1953 until 2010 is plotted against annual mean values of the various forcings whenever data was available. The R2 values are calculated for a standard linear regression as indicated by the shading (2s).

The primary message of this figure is the takeaway from the research: the correlation between sea-ice extent and CO2 is a remarkably strong 0.84.  Moreover, no similar correlation was found between sea-ice extent and any other forcing: not irradiance, PDO-index, AO-index (shown in figure above), cosmic rays, volcanic eruptions, or poleward oceanic heat transport (not shown in paper).  In other words, the set of explanations that skeptics like to use to explain away a multitude of climate change effects has been shown to not explain the decline in sea-ice.  Irradiance has a positive, but much smaller relationship than does CO2 concentration.  The PDO- and AO-indexes have no statistical explanation for sea-ice extent.

The paper includes this important passage:

Note that the same reasoning allows us to conclude that changes in CO2 concentration are not the main driver for the observed sea-ice evolution in the Antarctic. With no clear trend in the sea-ice extent there, there is virtually no correlation with the increasing CO2 concentration. This underpins the fact that in the Antarctic, sea-ice extent is at the moment primarily governed by sea-ice dynamics. In contrast, in the Arctic the sea-ice  movement is constrained by the surrounding land masses and the thermodynamic forcing becomes more relevant there.

At this point, the rise in CO2 remains the leading explanation for the decline in Arctic sea-ice extent.  Since this work was based on statistical analyses of observational data, I eagerly await observational-type climate change skeptics to accept the work as valid.  It won’t happen, of course, as I’ve found that the vast majority of skeptics won’t accept any amount or type of evidence.  That’s because the real issue is based on values, which skeptics don’t want to discuss.  Instead, they use climate change as a proxy argument.

For the rest of us, this is an important result.  I truthfully do await scientific responses to this work.  It should be challenged on legitimate scientific grounds, if it is challenged at all.


Leave a comment

Changes In The Arctic

I’ve written about Arctic sea ice conditions for a couple of years now. As I’ve written new posts, I’ve tried to include information regarding the science behind the conditions being written.  2010 was a particularly bad year for Arctic ice, as conditions were recorded to be well below average conditions for months at a time.  Arctic ice in September 2010 challenged the record low minimum extent observed in the modern era in 2007.  My summary conclusion after paying attention to Arctic sea ice is this: the Arctic has entered into a new climatic regime.  Conditions are now regularly quite different than those observed in the past couple hundred years.  I’m going to provide a broader look at this topic in this post.

When I have written about climatic changes, especially in the context of the Intergovernmental Panel on Climate Change’s 4th Assessment Report Physical Science Basis (IPCC 4AR WG1), I have increasingly mentioned the disturbing fact that the IPCC’s projections were far too conservative to be of real use to policy makers.  The reason is both simple and complex.  Simply put, the IPCC focused on moderate greenhouse pollution scenarios that were better researched.  The biggest problem with that is the globe’s actual emissions path is following the worst-case scenario (A1FI) considered by the IPCC 4AR (courtesy of Hansen and Sato; data through 2010):

Of greater complexity is the “better researched” part of my statement.  Critical feedbacks were largely kept out of climate model runs leading up to the 4AR.  There is nothing intrinsically wrong or manipulative about this.  Those feedbacks remain less researched and therefore less understood than other processes included in state-of-the-art model efforts.  That situation is improving, as feedbacks are coming under increasing scrutiny.  This is where politics intrudes: somebody has to fund that research.  There was a strong effort during most of the past 10 years to slow down or stop this kind of climate research.  Budgetary pressures moving forward will cause potential future research to be shelved when it’s needed most.

Back to the IPCC 4AR.  One of the problems with relying on scenarios that don’t accurately reflect the true state of the climate system is projections are starting to look overly cheerful.  Take Arctic sea ice extent as an example.  From the 2009 Copenhagen Diagnosis, we can see that not only does the mean of the IPCC models over-project the extent of September Arctic sea ice only a few short years after making the projections, but the worst-case scenario wasn’t able to capture how low sea ice extent would get prior to 2010 (data through 2008); [h/t msobel for reminding me this graph existed].

September 2009′s extent was similar to 2008′s.  2010′s looked more like 2007′s, which is represented by the lowest point of the red line in the above graph.  In other words, the observations time series continues to record values substantially lower than the bottom of the IPCC models’ range.  Scientists (and others) love to ask, “Why?”  So, the question should be, “Why were the IPCC models so far off on this projection?”  A quick note: a growing number of other kinds of projections are showing similar signs of being worse than projected much sooner than was thought to be the case.  I will discuss some, but not all, of the factors involved in this phenomenon.

I’ve already shown the annual growth of CO2 emissions over the past 50 years.  That, of course, is only part of the story.  Since CO2 isn’t scrubbed from the atmosphere very quickly, CO2 concentrations have risen with that growth of CO2 emissions.  Here is the state of atmospheric CO2 concentrations measured at Mauna Loa, Hawai’i as of early February 2011:

(Courtesy Tans et al., NOAA/ESRL web site)

Up and up it goes.  2010′s average CO2 concentration was 389.69ppm.  That will be the last time in a long time that the concentration will be below 390ppm.  Today’s concentration is higher than at any point during the past few hundreds of thousands of years.  Oh yeah, I almost forgot, the last time concentrations were above 400ppm for an extended period of time (somewhere between 400 and 560ppm), the Greenland ice sheets collapsed.  That’s because there is a melting ice/warmer air feedback that occurs around Greenland.  The problem?  Nobody knows exactly where the tipping point leading to collapsing ice sheet exists.  Since we’re only 10ppm  and 5 years away form 400ppm, does anybody seriously want to continue gambling?  After all, it’s going to take quite some time to get that concentration back below 400ppm; more time will be required the longer we wait.

CO2 is being emitted into the atmosphere faster than it is being removed.  The concentration of CO2 is therefore increasing.  As a result of very basic physical laws, more and more solar energy is accumulating in Earth’s climate system.  Part of this energy is manifesting as increased surface temperatures:

This graph shows 5-year and 11-year running averages of global temperatures as analyzed by NASA’s James Hansen.  Within this data, something interesting is occurring.  And it didn’t become obvious until Hansen published a different kind of temperature anomaly graph.  Instead of averaging the entire globe’s temperatures together, Hansen averaged temperatures over different latitude bands together:

If it’s too hard to make out all the little details, check out this web page, where you can click on a PDF which shows a much larger version.  I’m going to concentrate on the top two boxes in this graph, which show temperature anomalies for five zones (upper-left) and for the two polar zones (upper-right).

The first thing I want to point out is the period between 1940 and 1980.  This period has been cited recently by climate zombies as one reason not to listen to climate scientists.  According to the zombies, predictions were made in the 1970s about global cooling.  Nothing exists in the scientific literature supporting this claim, of course.  What scientists did say in the 1970s was the recent warming trend was no longer evidenced and they wondered what could be causing it.  Without getting further into the minutiae, the top two time series show where the global signal originated from: the Arctic.  It was the zone that showed the strongest signal that looks similar to the signal seen in the global temperature anomaly time series.  Since the 1970s, the Arctic’s surface temperatures have warmed more than any other zone.  You can see that in 2010, the Arctic temperature anomaly was greater than 3.6F (2C).  The northern mid-latitudes (23.6°N to 64.2°N, or the zone in which most of us live) has “only” warmed by just under 1.8F.  The northern mid-latitudes showed a slight cooling from the mid-1960s to the mid-1970s, but if you look at the time series on the bottom-left, the scale is much smaller than the Arctic graph in the upper-right.

So that’s what’s happened in the lowest part of the atmosphere above the Arctic: the greatest warming of any zonal area on Earth since the 1880s.  Arctic sea ice, of course, rests on water – the Arctic Ocean, to be precise.  Something has been occurring to the Arctic Ocean at the same time that the atmosphere above the ice has been steadily warming.  Unfortunately, it’s the same phenomenon: water entering the Arctic from the Atlantic is warmer than it has been at any point in at least the past 2,000 years.  This water is 3.5F warmer today than it was one century ago.  It is 2.5F warmer today than it was during a favorite time period for climate zombies, the Medieval Warm Period, during which Europe warmed while most of the rest of the globe didn’t see much change.  But even if the effect was global, as they wish it was, conditions are warmer today by a substantial margin.  Not only that, but the volume of water entering the Arctic from the Atlantic has also increased over the past century.  If the same volume of water that was warmer was the situation, that would be bad enough.  But significantly more water that is significantly warmer than similar water was 100 years ago is a double whammy.  What this mean is Arctic ice has a harder time forming along the edge of the ice pack on a year-to-year and decade-to-decade basis.  This is evident in the following graphic:

(courtesy Robert F. Spielhagen, Science)

The red arrows represent flow direction of Atlantic water entering the Arctic Ocean at depth.  The white arrows represent flow direction of ice exiting the Arctic Ocean at the surface.  The solid white line represents the average sea ice coverage for April from 1989 to 1995.  The broken white line represents the average sea ice coverage for April from 1963 to 1969.

Why are the time series and study results relevant to the comparison of ice extent observations against IPCC model projections?  Because they represent only a small number of examples of how increasing understanding of the Arctic has occurred in recent years and that’s problematic when interpreting the IPCC’s results.  I haven’t covered how the warming observed in the Arctic so far is thawing permafrost both on land and underwater, which is projected to release 1 Billion tons of carbon into the atmosphere yearly by the 2030s – and how such a process likely won’t be included in the IPCC 5AR.  Additionally, most of that carbon will be released as methane, which is 72 times as efficient a greenhouse gas over a 25 year period than CO2.  I haven’t covered how the retreat of Arctic sea ice is causing additional solar energy to be collected by dark sea water instead of being reflected back into space by white ice – and how such a process also isn’t included in today’s climate models.  I haven’t covered how over 80% of the solar energy absorbed in the past couple hundred years is currently stored in the world’s oceans, mostly at depth.  When that warmer water rises to the surface, it will interact with a warmer atmosphere in ways that are not completely understood.  Of course, warmer waters means Arctic sea ice will have even less of a chance of existing year-round in tomorrow’s world.

To some extent, I have talked about the dangers involved with spending most of our research time on moderate emission/warming scenarios, when our actual emission scenario is closer to the worst-case considered in the 2007 report.  But all of the feedbacks I’ve discussed so far are lacking from all of the emission scenarios.  What will happen when those feedbacks are included?  Instead of “5.0 °F with a likely range of 3.1 to 7.9 °F” for the A1B scenario or “7.2 °F with a likely range of 4.3 to 11.5 °F” for the A1FI scenario from the 4AR by 2100, the globe could experience 10-13°F warming by 2100.  Long before then, the Arctic will likely have attained a new stable climate; one that is quite different from the climate present during most of our species’ existence.

The Arctic has entered into a new regime.  Even climate scientists are playing catch-up right now, which means the American public is way behind in understanding what changes in the Arctic mean to them.

Cross-posted at SquareState.


2 Comments

State of the Poles – 10/4/10

The state of global polar sea ice at the beginning of October 2010 was once again very poor compared to climatological conditions (1979-2008). The Arctic ice extent was far, far below average for this time of year.  The Antarctic sea ice extent wass above average, but not nearly so much as was the case in the Arctic.  Unfortunately, global sea ice extent fell to ~17.5 million sq. km., something that has happened in only 2 previous Septembers: in 2007 and 2008.  The Northwest Passage and the Northern Sea Route are largely free of ice, allowing the Arctic Ocean to potentially be circumnavigated.

This post will mostly concentrate on the extremely poor conditions found in the Arctic this fall.  Antarctic conditions are not as extreme, largely and ironically thanks to the ozone hole over the continent which has kept stratospheric temperatures much cooler than they otherwise would be.  Eventually, our forcing leading to global warming will overwhelm the ozone hole cooling effect (and the ozone hole will gradually be “healed” anyway), which will cause long-term changes to Antarctica just like the Arctic.

Continue reading


1 Comment

State of the Poles – 9/7/10

The state of global polar sea ice at the beginning of September 2010 is once again very poor compared to climatological conditions (1979-2008). The Arctic ice extent is far, far below average for this time of year.  The Antarctic sea ice extent is above average, but not nearly so much as was the case at the beginning of August.  Unfortunately, global sea ice extent has fallen to ~18 million sq. km., something that has happened in only 2 previous Septembers: in 2007 and 2008.  The Northwest Passage and the Northern Sea Route are largely free of ice, allowing the Arctic Ocean to potentially be circumnavigated.

Each month and each year that goes by provides additional proof that the Arctic has entered into a new state; a different state than has existed for 1,000 years or more.  Monthly and yearly weather conditions have varied considerably over the past few years, as one would expect, but the end result has been nearly the same regardless of any specific condition: Arctic sea ice is declining year-over-year.  It is declining at a rate that exceeds scientific estimates from just a few years ago.  Climate change deniers keep prattling on about increasing sea ice, in direct contradiction to the physical realities before them.  I think most of the areas that have sea ice this September will not have sea ice by 2020.  Specific weather or geologic events might delay the year that occurs slightly, but I don’t think it will take too much longer to witness an Arctic Ocean that is essentially ice-free.

Continue reading


3 Comments

State of the Poles – 8/7/10

The state of global polar sea ice in July 2010 is somewhat poor compared to climatological conditions (1979-2008).  The Arctic ice extent once again finds itself far below average extent for this time of year.  In contrast, the Antarctic sea ice extent remains significantly above average conditions.  Given those two quite different stories, the fact that global sea ice extent has once again fallen below 19  million sq. km., just as it has the past five consecutive years and eight out of the past nine, speaks to the dangerously poor condition of Arctic sea ice.

A quick aside: it’s not just the regions north of 60 that are experiencing ridiculous warmth this year.  As I’ll detail further in my upcoming post on the NASA & NOAA global temperature datasets, numerous areas across the Northern Hemisphere have experienced record breaking heat this summer.  Washington D.C. has witnessed its warmest June-July on recordMoscow has experienced its warmest temperatures on record, while massive wildfires rage across the Russian countryside – burning both forests and peat bogs (all of which releases even more CO2 into the atmosphere).  All-time record temperatures for country after country has fallen this year – further speaking to the dead seriousness of climate change’s effects now beginning to take hold.

Continue reading

Follow

Get every new post delivered to your Inbox.

Join 247 other followers