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:

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.

Research: Sea-Level Rise in Response to Warming Climate

From the top, I want to include important context for the research results I am presenting.  This research is based on peak warming of only either 1.5°C or 2°C.  It is my educated opinion that such goals are unrealistic.  Prevention of warming past 2°C is no longer a viable option based on the globe’s history of burning carbon-intensive fossil fuels as well as the medium- to long-term future, which doesn’t promise much of a difference.  Furthermore, as I have stated numerous times in the past year, policy discussion would be better served if scientists would conduct research on developments that are much likelier to occur and not the world they want to see (i.e., higher vs. lower emissions scenarios).  That said, this research fulfills an important role in the overall discussion because I think some of the results can be used as a “floor” – conditions are likely to reach higher magnitudes than those found in this and similar papers.

Michiel Schaeffer, William Hare, Stefan Rahmstorf & Martin Vermeer’s Nature paper was published on June 24, 2012.  They examined sea-level rise in response to warming scenarios using a semi-empirical model.  By 2100, global sea-level rise would be ~60cm above the 2000 level if global GHG emissions were zeroed by 2016.  This is an obvious fantasy world, but it provides a useful benchmark for other scenarios the scientists examined.  The reason sea-level rise would continue through the 21st century even if we haled emissions completely in the next 3-4 years is the response of the climate system to the anthropogenic forcing imparted on it through the 20th and early 21st centuries.  If 1.5°C or 2°C warming is not exceeded, global sea-level rise would be 75-80cm above the 2000 level.  The authors also report that unmitigated emissions could result in 100cm rise above 2000 levels.  It is important to note that 20th century sea level rise has been estimated to be ~20cm.  It doesn’t require much thought to realize that the rate of sea-level rise has increased throughout the 20th century and continues to do so in the 21st.  Moreover, it is clear that since we will most likely warm beyond 2°C, the 75-100cm projection can be viewed as a reasonable estimate for a “floor”: actual sea-level rise could be greater than this.

Sea-Level Rise Accounting; Climate Negotations; UK Energy Bill

An estimate of terrestrial water storage changes in the recent past (1961-2003) provides a potential answer for a significant portion of total (~42%) sea-level rise in a new study (summary):

The next round of climate negotiations are in Bonn, Germany this week.  Countries are trying to come up with the next climate agreement, but members disagree over whether and how such a measure would bind them.  I’ve concluded in the past year that international efforts haven’t and won’t work for the foreseeable future.  There are simply too many interests at the table trying to conceive something from scratch and the technological solutions aren’t readily at hand.  I think it would better for interested parties to form smaller groups and work on mutually beneficial goals with an eye toward keeping any agreements flexible and dynamic to accommodate new members and goals as needed.  The focus on a grand global bargain isn’t and won’t get the job done.

The U.K. is working on an energy bill and this article asks the question: will the bill help the U.K. meet its climate (emissions) goals?  Call me Debbie Downer, but the answer is relatively easy: no, it will not.  Nothing that is politically feasible in the UK (or US) right now will meet any kind of emissions goals in any time frame (unless those goals include larger numbers than exist today.)

The government is committed to decarbonising electricity generation by 2030, as well as slashing overall carbon dioxide emissions by 80% by 2050.

The UK will not decarbonize electricity generation by 2030.  Any way you look at it (e.g. here or here), the UK generates most of its electricity with fossil fuels (coal and natural gas).  Renewable sources are responsible for only ~3.5% of the electricity generated.  Is the UK seriously going to replace all currently existing coal and natural gas plants with renewable sources in 18 years, to say nothing of expectations of increasing electricity demand in that 18 year time span?  The scale of that project boggles the mind – it simply will not be accomplished.  And just so I am clear, the same thing holds true for every other nation, including the US.  This is exactly the type of project I worked on late last year – and I promise I will share those results in the future.  I look forward to hearing from my favorite UK blogger (Martin) both now and when I put that future post together on this topic – what think you?

Canadian Glaciers, Ice Caps Melting Too

Glaciers and ice caps in the Canadian Arctic Archipelego have started melting.  This will contribute to sea-level rise for the remainder of the 21st century.  That’s a problem because the area contains one-third of the global volume of land ice outside the ice sheets.

Researchers found that the islands lost about 61 gigatonnes of ice per year from 2004 to 2009, enough to raise global sea levels about a millimeter in that time.

That rate of melt will only increase in the years ahead.  More mass into the world’s oceans and more heat accumulated from global warming means the rate that sea level rise is increasing will also increase.  And because of the out-sized influence of the dirty energy industry and its apologists, we remain unprepared for that situation.  Preparing for it will only become more expensive with time.

Climate Tipping Points Better Defined: Likely Nearby; Strong Action Critical

NASA’s James Hansen and Makiko Sato have a new draft paper that brings potential climate tipping points into more focus and the results are incredibly important.  They examine some differences between two recent geologic times, the Eemian and the Pliocene, and today.  During the Eemian, sea levels were 15-20 feet higher than today.  During the Pliocene, sea levels were 82 feet higher than today.  If we maintain our business-as-usual (BAU) greenhouse emissions path, the authors state that multi-meter sea level rise within this century becomes “almost dead certain” because of nonlinear responses to that forcing.  To be clear, that means that future temperature increases will not be equal for the same amount of future emissions.  Instead, future emissions will cause a radical and unreversable jump in global temperatures, which will lead to radical jumps in sea level rise.  We won’t have a 1″ per year increase in sea level.  The difference year after year will be greater and greater as the climate system attempts to find a new stable region.

I want to point out that Hansen and Sato use extremely strong language for climate scientists.  Will it be strong enough to generate the political will necessary to take us off that path?

Will Work To Clean Up Everglades Matter?

Back in 2000, the Comprehensive Everglades  Restoration Plan was initiated by the Army Corps of Engineers.   Consisting of over 50 major projects to bring the Everglades back from the brink, the program has thus far mostly been a success.  It’s cost more than originally planned, but measurable progress has been made.

My question is, how much is the multi-billion dollar project worth to Floridians and Americans?  What I mean by that is, within a few decades, the Everglades will be sitting at the bottom of the Atlantic Ocean if nothing is done to slow down global warming.  Will those billions be wasted in trying to save the Everglades from fresh water flow problems while sea levels continue to rise?  How many more billions would Americans be willing to spend to build and maintain infrastructure to keep the sea water out of the Everglades?

We can continue rumbling down the dangerous path we’re on and refuse to take the threat of global warming seriously or we can choose to acknowledge the reality we’re facing and do something about it now, while we still can.

21st Century Sea-Level Rise: More Than IPCC 4AR Projected

New research was published a few months ago that provides additional evidence that sea-level projections made by the IPCC’s 4th Assessment Report are likely too conservative: sea-levels are more likely to be 1 meter higher than they were in 1990 (Vermeer and Rahmstorf), rather than only 0.5m higher, as projected by the IPCCs multi-model ensembles.

There was nothing inherently bad about the IPCC’s 4AR; I and others simply feel that their final report had to include more conservative estimates and projections in order for world governments to sign off on its language.  That does the world’s citizens an injustice, however.  In order to correctly assess risk, people need best- and worst-case scenarios available to them.  The most likely amount of sea-level rise by 2100 provided by the 4AR came out to between 0.2m and 0.6m.  Those estimates have implications to world societies, conservative though they were.  Additional implications will enter into our lives if there is 0.4-0.8m additional rise.

I want to stay on the IPCC projections for another moment.  The 2007 estimates included rates of sea level rise between 1980 to 1999 and 2090 to 2099 in metes and mm/yr.  The mm/yr rates in particular interest me because they allow for both the IPCC projections and the updated projections from the Vermeer and Rahmstorf paper to be placed in context with actual observations.  The six emissions scenarios examined by the IPCC had rates of 1.5, 2.1, 2.1, 1.7, 3.0 and 3.0mm/yr.  Satellite observations indicate that there has been approximately a +3.2mm/yr change in sea level (linear fit since 1993).  Only two IPCC emissions scenarios are close to the observed rate, and both of them underestimate them, albeit very slightly.  It is worth pointing out that the IPCC wrote:

The global average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961-2003.

Averages over longer periods of time like this will, by nature of the averaging, tend to reduce extreme values that are small in number, as in the case of sea-level rise in the past 10 years or so.

Onto the new research findings.  Vermeer and Rahmstorf developed and tested an updated methodology to project future sea levels based on projected changes in temperature that was originally presented by Rahmstorf in a separate paper.  The original technique was based on the assumption that the sea level response time scale was long compared to the time scale of interest.  The updated technique allows for some sea level components to change quickly to a given temperature change.  The updated technique is shown to agree very well with historical data (82% of sea-level rate variance from the year 1000 to 2000).

Applying the technique to future conditions provides another potential case against which real-world observations can be compared.  By the year 2100, three different IPCC emissions scenarios generate a range of sea level projections: 1.0m, 1.2m and 1.4m, as the figure below (from the paper) shows.  That’s a big difference between the AR4 projections, using the same emissions scenarios, of 0.2-0.4m.  That extra potential meter of sea level rise will indeed have large implications across the world.

The figure shows the possible range of sea level rise values for 3 emissions scenarios considered by the IPCC: B1 in green, A2 in blue and A1F1 in yellow.  The observed emissions to date is represented by the red curve.  One important detail to note is our actual emissions rate is currently at the high end of all those considered by the IPCC (Copenhagen Diagnosis Figure 1, after Le Quere et al. 2009).

The IPCC projected a higher future rate of sea-level rise than was observed from 1961-2003.  1.8mm/yr equals 0.18m after a century (by linear extrapolation), slightly below the 0.2 minimum projected by all emissions scenarios.  Recent observations of 3.2mm/yr equals 0.32m after a century – well within the IPCC range, but well below the Vermeer and Rahmstorf range.  So what will it take to get 1.0-1.4m of sea level rise by 2100?  10mm-14mm/yr or 3-4X as much per year as is currently being observed.  There are some important details involved with that projection.  First of all, sea level change is not linear.  It varies year to year and decade to decade.  There has to be a transition from today’s 3.2mm/yr to the 10mm/yr necessary to achieve 1m sea level rise by 2100.  The rate of sea level rise would therefore have to increase over time.

Given the state of today’s atmosphere, oceans and cryosphere, a drastic change would have to occur for sea levels to rise by 10mm+ per year by the end of this century.  It is widely known that the IPCC’s science basis did not include a number of processes and feedbacks to the globes’ continental ice sheets, glaciers and sea ice (cryosphere).  Again, that wasn’t their fault – it just happens to be a weak link in the climate community’s research.  Work has been conducted since the IPCC 4AR to rectify those shortcomings.  Much more work will have to be done in the future.  Once that area is fleshed out further, I expect the IPCC’s projections to be more closely aligned with the leading research of today.

h/t RealClimate

http://sealevel.colorado.edu/

Rising Sea Levels: Disappearing Islands & Underestimation

Word came yesterday of an island in the Bay of Bengal that has quietly slipped beneath rising seas.  New Moore Island was a rocky island that was 2 miles long and 1.5 miles wide.  This isn’t the first island to succumb to rising sea levels, nor will it be the last, especially since we continue to belch greenhouse gas pollution into the atmosphere.  Indeed, 10 additional islands in the same area continue to face submersion in the near future.  This news isn’t a surprise to any reputable scientist who has studied climate change, nor to any activist who has followed the state of the science.

Also unsurprisingly, Sen. James Inhofe’s family was not photographed on New Moore Island constructing a building in further efforts to misinform the fringe anti-science crowd.  I’m sure the lunatic Senator would cite his favorite conspiracy of global economic domination as the real topic to be discussed.  It wasn’t his island that disappeared, after all.  You’ll also note that the disappearing islands don’t garner much corporate media attention.  Since the stenographers look for controversy, there must be a lack of dimwits who are willing to go record disputing these events.

Pine Island Glacier Past A Tipping Point?

A major glacier located in West Antarctica could, according to recent research, be near or past a tipping point, beyond which the glacier will inevitably slide into the ocean.  Pine Island Glacier has had its grounding line, the area where the glacier rests either on the ocean or land, pushed back toward land due to increasingly warm ocean temperatures melting it from below.  If it retreats behind a lip on the continental shelf, rapid and irreversible loss of ice will occur.

Investigation into the glacier indicates that the grounding line may have retreated behind the lip back in 1996.

Research indicates that before the next stable grounding line can be reached on the inner slope, half of the land-based glacier will have melted into the ocean.  Melting land-based glaciers result in rising sea levels.  Half of Pine Island Glacier would raise sea levels by 9″ before 2100.  If a nearby glacier also retreats, sea levels would rise by 20″.  Either case would result in the displacement of millions of people worldwide, likely leading to the collapse of stable governments.

Tipping points can no longer be viewed as future abstractions.  We are already passing them, cementing disastrous events in our future.  How many we pass, and by what degree, is up to us.

2009 Copenhagen Climate Summit News 12/11/09: 1st Draft Issued & Wingnuts on Parade

The first official draft on a climate deal has been written and issued.  The expectation is the details won’t be worked out for another 6 months or so, which was what a lot of people were thinking going into this Summit.  Keep in mind that George Bush’s crew did everything they could for 8 years to make sure the climate crisis was worse when they left than when they took power.  President Obama’s administration has had only 10 months so far to undo those 8 years of damage.  That little fact will be very handy when the Cons start screaming that the Summit and the U.S. President are failures.  Gotta love those patriots!  Back to the draft:

A key working group under the UN Framework Convention on Climate Change (UNFCCC) came up with a six-page text Friday. The draft may form the core of a new global agreement to combat climate change beyond 2012, when the present framework, the Kyoto Protocol, expires. However, most figures in the text are shown in brackets – meaning that there is not yet agreement on these specifics. Most importantly, the draft states that emissions should be halved worldwide by 2050 compared to 1990 levels, but it also suggests 80 percent and 95 percent reductions by that year as possible alternative options.

Those two emphasized statements are at the root of a lot of disagreement between parties, as I cover below.