2011: 9th Warmest Calendar Year On Record, Even With A La Niña

NASA’s James Hansen and a few of his colleagues released their assessment of 2011 global temperatures recently.  In short, 2011 was the 9th warmest year in the GISS dataset.

Just as importantly, this situation occurred in the midst of a continuing La Niña event that is of moderate strength.  La Niña is characterized by a general cooling of the tropical Pacific waters near the surface; it is frequently referred to as being the opposite of El Niño.  As La Niñas progress, global temperatures tend to cool from their normal state.  This of course has implications as scientists work to differentiate the effects of natural climate processes and those brought about by humans.  If one year’s temperatures are cooler than the preceding year’s (or are warmer), does that mean that global warming has stopped (as skeptics like to say) or does that mean that there are competing forcings that affect the temperatures recorded?

It is the assessment of an overwhelming majority of climate scientists that global warming has not stopped.  Instead, the 2nd half of 2010 and all of 2011 were dominated by La Niña events.  What does this mean?  It means that if the La Niña events had not occurred (and if there were no El Niños either), in other words purely “normal” conditions, 2011 likely would have been warmer than was recorded.  This should become obvious in the next 6 months to 3 years as this La Niña dissipates and conditions across the globe respond accordingly.  It takes ~6 months for downstream effects to show up in observations after ENSO phases start and after they go away.

Here is Hansen et al.‘s updated figure showing global land-ocean temperatures using an index:

Figure 1.  Global surface air temperature anomalies relative to 1951-1980 base period for annual and 5-year running means. Green vertical bars are 2σ error estimates (Hansen et al., 2010). [Source for all graphs: Hansen]

The last black square on the right hand side of the graph is 2011′s temperature index value: +0.51°C.  You can clearly see where the 9th highest ranking comes from when viewing this graph.  You can further see that 2011 was warmer than 2001, 2004 and 2008 (simply comparing the past 10 years of values), as well as every year prior to 2000 save 1998, the year when the last century’s strongest El Niño occurred.

But I wrote above that large changes can occur year-to-year and this is evidenced by the jagged look to the yearly data in the graph above.  So what happens if the data is analyzed in such a way as to remove the yearly signal?  Furthermore, can the ENSO and solar cycle signals be quieted down to get a better idea of what the global temperatures are likely doing?  Yes they can, as the following graph demonstrates:

Figure 2. Global surface air temperature anomalies relative to 1951-1980 base period for (a) the 12-month running mean, and (b) the 60-month and 132-month running means.

The right panel of Figure 2 demonstrates the results of the removal of the ENSO signal (red line, 60-month running mean) and the solar cycle signal (blue line, 132-month running mean).  The addition of more months into the running mean helps to remove more and more noise (to a limited degree, of course).  What is left behind is increasingly the global warming signal in global temperature data.  A key takeaway is this: the same general result can be seen regardless of the specific temperature dataset employed.

To expand on this topic a little more, here is a graph comparing mean temperature anomalies and the Nino 3.4 index (and index used to characterize the ENSO signal as El Niño or La Niña):

Figure 3. Global monthly and 12-month running mean surface temperature anomalies relative to 1951-1980 base period, and 12-month running mean of the Nino 3.4 index.

Paired with the Nino 3.4 index data, it is very easy to pick out the ENSO influence on the temperature data.  Peaks in global temperature anomalies tend to occur during El Niños while troughs in anomalies tend to occur during La Niñas.  As you can see, claims that global warming has “stopped” in the past couple of years are not likely to be correct since a prolonged La Niña has occurred during that time frame.  One good indicator of whether or not global warming has stopped will be what the global temperature anomaly is ~6 months after the next El Niño peak occurs (likely sometime in the next 3 years).

Another good indicator of whether global warming has stopped or not will be what global temperature anomalies register as the upcoming solar maximum descends from its next peak.  As the following graph illustrates, the peak is likely to occur 3+ years from now:

Figure 4. Solar irradiance from composite satellite-based time series. Data sources: For 1976/01/05 to 2011/02/02 Physikalisch Meteorologisches Observatorium Davos, World Radiation Center and for 2011/02/03 to 2012/01/11 University of Colorado Solar Radiation & Climate Experiment. Data are concatenated using the 2010/02/03 to 2011/02/02 period.

It is important to note that the global temperature response to the solar cycle is delayed by ~18 months.  So in 4-5 years from now, we’ll have a much clearer idea of the effects of global warming in the 1st half of the 2010s were.  That time period will occur after the next solar cycle maximum and after the next El Niño.  It strains credulity to think that global temperatures will be lower after those two milestones than they are today.

My thoughts on this are easily understood: it is more likely that global temperature anomalies will continue to exhibit decadal-scale rises than falls in our future (21st century).  As I’ve stated many times before, it is also likelier that projected temperature increases are underestimated, not overestimated.  We are more likely to read about additional top-10 warmest year on record in our future.  That said, I’d be happy to be wrong about all of this.  The changing environment we’re living in demands changes to the way our societies function.  I don’t believe those changes will be equally catastrophic to everybody around the globe.  But all of us will be affected by this phenomenon in one way or another.  How we decide to handle those changes will be the key.

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.

Climate Change Solutions – Where We Need To Go

Climate change is a monumental problem.  I characterize it by saying that it is our species’ greatest confirmed threat.  Nuclear war?  Possible but unlikely in any given decade.  An asteroid/comet collision with Earth resulting in an extinction level event?  Possible but unlikely in any given decade.  I would, however, rate the asteroid/comet threat above nuclear war.  One day, the former will happen, we just don’t know when; the latter can be held off and eliminated based on our own decision making.  In a way, climate change combines aspects of both of these threats.  Climate change (at a level that will challenge our civilizations) is both possible and likely in a given decade; it is currently happening and its magnitude will only increase each decade during the rest of this century unless and until we decide to do something about it.

It should not be surprising then that, given the sheer magnitude of catastrophic climate change, solutions addressing it are also monumental in scale.  That’s the root of why so many climate change activists have been calling for a “climate-Manhattan Project” or a “climate Apollo Project”.  My view on climate change actions has shifted somewhat from thinking a bunch of personal actions will eventually accumulate enough inertia to reduce our climate forcing to recognizing that the number of actions will require large-scale policy shifts – something that requires governments to act.  That’s why the U.S. Senate’s recent failure to seriously address this developing crisis is so maddening.  The status quo approach to policy will not work with climate change, mostly because we’re dealing with physical systems that respond to forcing, not people’s tender egos and greed.

Hansen Sets CO2 Target; California Sets Aggressive Renewable Target

James Hansen was the lead author of a paper recently, “Target Atmospheric CO₂: Where Should Humanity Aim?“.  It appears in the latest edition of the Open Atmosphere Science Journal.  I just finished reading the paper when an article on it appeared on CNN’s website.  I will have much more on this paper, and others I’ve read recently, in the future.  In short, the article makes the argument that CO2 concentrations are already too high.  To avoid a return to the early Cenozoic Period climate, humanity must act immediately.  350ppm is the target.  We’re currently at 385ppm, and that’s currently going up by 2-3ppm per year.

In related news, California Governor Arnold Schwarzenegger has issued an executive order calling for a 33% Renewable Portfolio Standard by 2020.  That is significant.  If California were it’s own country, it would have the 7th largest economy in the world.  An aggressive goal like this will lead the way for the remainder of the country to establish and improve upon renewable energy sources.  California is looking at a greenhouse gas reduction goal of 1990 levels by 2020 and 80 percent below 1990 emissions levels by 2050 pretty seriously.  Will it be enough?  Certainly not if California acts alone or nearly alone.  The U.S. needs to adopt a similarly aggressive stance.  As Hansen’t paper points out, CO2 concentrations are too high already.  Everything we do today to bring that concentration down is less we have to do tomorrow.

Linkies 1/30/08

James Hansen tells it like it is; Climate Progress has a quote.

A Clean Air Group is suing Xcel over alleged pollution standards. Total estimated cost if guilty? $400 million. Even if Xcel is guilty, there’s no way they’ll end up paying that much money. A settlement is much likelier.

Climate Progress’ take on Bush’s ‘discussion’ of energy during the SOTU.

“The Earth’s climate is now clearly out of balance and is warming.” So says the American Geophysical Union. Any solution? “Mitigation strategies and adaptation responses will call for collaborations across science, technology, industry, and government.” Not going to happen with the Neandertals currently pulling the levers. 2009 and 2010 will be too late. Get ready for a vastly different planet.

More good ideas from Trapper John.