Research: Climate Change Permanency

I’ve written a couple of posts on climate change basics (Gases, Forcing & Surface Temperature and Energy & Projections) that described how energy enters and moves through the climate system and some physical ramifications of emitting greenhouse gases.  This post will build on those in an important way by examining what is very likely to happen to the base climate system in response to increasing carbon emissions.  The operative word that is used throughout is: permanency.  The climate system has so far been slightly altered by our species’ emissions.  Most of the effects of that alteration won’t go away for hundreds of years.  As humans emit additional emissions, the effects grow.

For all intents and purposes, as far as our species is concerned, the climate system’s alteration will not go away for a long, long time – on the order of thousands of years.  That’s permanency as far as we’re concerned.  Or, as the paper I cite puts it: it’s irreversible.  Conditions will very likely not return to those we’ve experienced in our lifetimes and in the past few thousand years for many thousands of years into the future.  That’s the cold, hard scientific truth of the situation.  Now, people can decide for themselves whether such irreversibility or permanency is a “good” or “bad” thing – I won’t make normative judgments for anyone else but myself.  I don’t consider such a change a “good” thing.  The effects I will describe here are significant, but they are only those that are easily projected.  Many other effects that haven’t been considered or experienced by our species will almost certainly fall out as a result of projections discussed here.  Our civil institutions are not well equipped to handle even the first-order effects, let alone the compounding influence of effects upon effects.

On a personal note, I will not describe things as ‘catastrophic’ anymore.  I have hinted at this in some posts I’ve written in the past few months without much explanation.  The primary reason for this is using such language simply turns people off from considering the material.  I think we need more people engaged on this topic, not less, and will consider scientific results of language and framing as much as I consider climate science results (a post dealing with this specifically is in the works).  That said, I will continue to not spend many resources to engage the ideologically driven skeptic community.  They simply have a different worldview than I do and neither party will convince the other that their side is “correct”.  One goal of this blog is to inform those who are interested and to have civil, productive discussions of peer-reviewed climate science and the political/policy implications of that science.

So, before I delve into some details, words like `permanency` and `irreversible` will be used more frequently on this blog in the future.  I will not use words like catastrophic.  On that note…

Susan Solomon and her coauthors published a paper in 2008 entitled, “Irreversible climate change due to carbon dioxide emissions.”  The primary finding: climate change resulting from anthropogenic carbon dioxide emissions is largely irreversible for 1,000s of years after the emissions stop.  As a result, atmospheric temperatures are likely to remain higher than present-day values, rainfall reductions during dry seasons are likely to occur across the planet, and sea level rise is likely to continue to occur for thousands of years even though the models they used did not include every physical process involved in the hydrologic cycle in addition to the noted lack of all first-order forcings.  The study gives us an idea of the type of temperature trends we are likely to experience for the next few thousand years as well as a conservative estimate of how high average global sea level rise will be.

In similar fashion as other modeling work, Solomon et al. allow CO2 concentrations to rise, then halt suddenly at some level in the future (reflecting a dramatic shift in human behavior such as radical technological innovation, etc.  I characterize this treatment of behavior as “magical” because there is never robust reasoning to adequately describe such behavior shifts).  Concentrations in the study rose at 2%/year to peak CO2 values of 450, 550, 650, 750, 850, and 1200 ppmv, followed by zero emissions after hitting each peak.  For reference, current annual CO2 concentrations average just over 390pppmv.  What occurs after the peaks is the interesting part of this paper, as the following graph shows:

The x-axis shows time in years out to the year 3000.  Pre-industrial CO2 concentrations are indicated by the dashed line near the bottom of the graph.  Without any effort at emissions’ mitigation, any one of these peaks is well within the realm of possibility. What happens after each peak?  An extended period of time during which CO2 concentrations remain much higher than pre-industrial levels.  Concentrations remain at levels between ~300 to ~800ppmv for the next thousand years, decreasing at decreasing rates during and after they reach their respective peaks.  What effect might this have on temperature?  The next graph in the paper demonstrates the simulated effects:

Each curve in this graph corresponds to the emissions lines in the previous graphs.  Temperatures remain at least 1°C warmer (and up to 4°C warmer) than those of the year 1800 for the next thousand years.  Temperatures do not decline at nearly the rate that CO2 concentrations do in the latter part of the millenium.  While CO2 concentrations remain higher throughout the period, “permanency” is evident by temperature trends through the year 3000.  What does that mean for the real world?  Whatever temperature shift takes place through the end of rising emissions stays in place for all intents and purposes for our species permanently.

Rising temperatures have many other effects on different earth systems, including sea levels.  Here are the sea level change projections from the Solomon et al. study:

Again, each line in this plot corresponds to an emissions scenario and a temperature trace in the two previous plots.  Note the y-axis on this plot: it only shows sea level rise due to thermal expansion.  Any additional water entering the world’s oceans resulting from melting glaciers or land-based ice sheets are not included in this projection.  Therefore, the reader can interpret this plot as a minimum of sea level rise through 3000.  The greatest rise obviously corresponds to the highest emissions scenario and the highest temperature rise.  0.4m rise in the minimum projected by this study and 1.9m is the maximum.  Similarly to the previous plots, sea level doesn’t decrease once emissions and temperatures stabilize.  Instead, they continue to slowly increase throughout the next millenium and remain high in essence in a permanent sense.

What’s obviously inaccurate with this study is the instantaneous cessation of CO2 emissions.  Many studies treat future emissions in similar fashion.  How emissions decrease in the future is of course a large unknown and therefore impossible to model with high accuracy.  Solomon et al. do acknowledge that their treatment of emissions is not meant to be realistic, but to “represent a test case whose purpose is to probe physical climate system changes”.  The primary lesson from this paper is relevant no matter the specific future emissions pathway: the longer emissions continue at any level close to 20th century levels, the longer it will take before concentrations stop rising and begin their slow descent in a planet with full carbon sinks, and temperatures and sea levels stabilize.  The point at which all of these conditions peak is, in the end, almost entirely up to us.

The policy implications of this and other studies are obvious and not-so-obvious.  Among the former: the willingness of coastal residents to incur higher infrastructure and other costs in future years versus their desire to implement policies designed to mitigate their situation; the willingness of non-coastal residents to keep funding federal insurance programs that allow others to live in high-risk zones; the way in which municipalities write zoning laws: for developers or for citizens; policy development that will help populations adapt to climate change effects in their region and/or that address mitigation on a larger scale; the priority assigned to programs that may or may not generate technological innovations that would lead to adaptive or mitigative strategies at some undefined point in the future (via government or business); how to address the need that policymakers have for information that will facilitate a balanced approach between short-term gain and long-term risk management.  Other implications exist, as I’m sure most readers can attest.  One result of this study is clear: we have locked in a certain amount of costs just as we’ve locked in a certain amount of warming and subsequent changes in multiple earth systems.

Ocean Acidification: 100X Faster Than Last Similar Event

Last week, I wrote about a study that had found warmer waters reaching the glaciers of Greenland, helping to melt those glaciers from below while warm temperatures melt them from above.  This scenario presents numerous dangers for societies around the world.  Faster melting glaciers means faster rising sea levels, which means more impacts sooner.

Today, I will write about a scenario that is potentially more threatening than glaciers melting faster than expected.  New research demonstrates that the oceans are acidifying more quickly than has happened naturally for tens of millions of years.  The threat that presents is when the last similar acidification event occurred, upwards of 50% of marine life went extinct.  It took hundreds of thousands to millions of years to recover from this catastrophe.  It is known as the Paleocene–Eocene Thermal Maximum, or PETM, and it happened 55 million years ago.  The event saw global temperatures rise by around 6°C (11°F) over 20,000 years, with a corresponding rise in sea level as the whole of the oceans warmed.  To put that warming in context, climatologists are warning that global temperatures could rise by a similar amount over ~200 years.  That’s 100 times faster than the last rapid global warming event of similar magnitude.

How Declining Arctic Ice Volume Affects Northern Hemispheric Weather Patterns

Evidence continues to emerge regarding the effects of declining ice volume and areal extent in the Arctic is affecting weather patterns across the Northern Hemisphere.  In a general sense, some kind of effects are of course to be expected.  But what kind, what are their magnitude, etc. need to be explored.  If it were up to the Cons, science would be defunded and we would have no idea what these emerging trends are.  This is the critical importance that science plays in our society.

I’m going to link to another diary and allow readers to explore the material there.  It’s decently written and links to science centers and refereed journals.  Here is the summary:

Today’s Arctic sea ice extent is hovering at the historic record low level for today’s date observed in 2007. Warm water entering the ice free zone from the Atlantic ocean is adding heat to the Arctic, changing the northern hemisphere atmospheric circulation pattern – the weather of the whole northern hemisphere. Even El Nino is different from what it used to be.

Enjoy.

U.S. Record High Temperatures Recorded At Twice The Rate Of Record Lows This Decade

A news release was issued last Thursday that I flat out missed, which was unfortunate (though I’m glad I eventually found out about it).  A study (submitted to Geophysical Research Letters for publication) was conducted by climate scientists at the National Center for Atmospheric Research (NCAR) in Boulder, CO, Climate Central in Princeton, NJ, the Weather Channel, and the National Climate Data Center in Asheville, NC.  They examined trends in record high temperatures and record low temperatures over the past 6 decades, through 2006.  What they found isn’t terribly surprising: the ratio of record highs to record lows became unbalanced in the 2000s.  There were twice as many record highs as record lows across the continental United States.  That’s an increase from 1.36:1 for the 1990s and 1.14:1 for the 1980s.  Climate change is affecting us today.  Not tomorrow, not later this century.  Today.

Even Progressive Senators Don’t Grasp Importance of Climate Change

I read a blog post about progressive Senate Democrats pushing Sen. Reid for a public option.  I wholeheartedly support such a push for a number of reasons.  Because I’m like most Americans, I encourage the push because I want true health care reform legislation to pass.  Not the watered down health insurance “reform” crap that CorporateDems and Republicans have forced in the House, but real reform, which is increasingly more unlikely this year, to the detriment of our country.

Wilkins Ice Shelf Bridge Collapses

The state of the Antarctic ice shelves continues to deteriorate.  Following the end of the 2008-2009 Southern Hemispheric melt season, a bridge holding the Wilkins Ice Shelf to an island off the coast of Antarctica has finally collapsed.  I wrote about the worsening conditions that the Wilkins Ice Shelf was facing here and here (this second post was written just about one year ago, actually).  The Wilkins Ice Shelf will now be able to calve (break up and float away in ocean currents) allowing continental ice to flow to the ocean more quickly.

The National Snow and Ice Data Center in Boulder, CO has the following two pictures – the first from two months ago (Feb 3) and the second two weeks thereafter (Feb 17):

Since the 2nd picture was taken, the ice bridge collapsed.  It was providing stability to the Wilkins Ice Shelf behind it.  In the 1990s, the Wilkins Ice Shelf measured about 5,000 square miles in area.  In 2008 alone, nearly 14% of the ice mass (~700 square miles) melted.  The Western Antarctic area has seen the largest amount of warming of all of Antarctica.  Similar, though much smaller shelves have broken off in recent years as warming air temperatures and warming sea temperatures attack them from two sides.  This BBC article describes the situation:

Many of its ice shelves have retreated in that time and six of them have collapsed completely (Prince Gustav Channel, Larsen Inlet, Larsen A, Larsen B, Wordie, Muller and the Jones Ice Shelf).

When Wilkins calves, it is expected to be the largest calving event seen by modern people.  Once that happens, ice sheets on continental Antarctica nearby this shelf won’t have thousands of square miles of ice holding them back from the ocean.  This acceleration phenomenon and its effects were not included by IPCC) when it made its latest projections on likely future sea level rise. Its 2007 assessment acknowledged that ice dynamics were poorly understood.  More recent studies recognize that warmer polar conditions will also lead to 30% less ice coverage in the Arctic, due in no small part to the very thin ice volume left after recent melt seasons.

These events are occurring many years ahead of recent projections.  The state of the climate system is worse than many assume.  We are running out of time to act and actions like Democratic Senate “moderates” forcing 60 votes to pass meaningful climate legislation clearly are not taking into account the following:

* Staggeringly high temperature rise, especially over land — some 15°F over much of the United States
* Sea level rise of 5 feet, rising some 6 to 12 inches (or more) each decade thereafter
* Widespread desertification — as much as one-third of the land

These impacts and more will be the results we witness by 2100 if we don’t act to stop them today, as I think the Obama administration believes.  Read this quote from Sec. of State Clinton at a two-week conference of parties to the 50-year-old Antarctic Treaty:

“With the collapse of an ice bridge that holds in place the Wilkins Ice Shelf, we are reminded that global warming has already had enormous effects on our planet, and we have no time to lose in tackling this crisis,” she told the first-ever joint meeting of Antarctic Treaty parties and the Arctic Council at the State Department.

I certainly can’t imagine any Bush “administration” officials saying such a thing.  In this sense, change has come to Washington.  Will Sens. Udall and Bennet agree when the time comes to make the hard votes?  Forcing 60 votes to maintain tradition and come across as “bipartisan” sounds really good.  5 feet of sea level rise, desertification of U.S. land and 15°F warmer temperatures do not sound really good.  When the time comes to make those hard votes, not only do I expect Sens. Udall and Bennet to vote to do something concrete, I also expect them to bring more than enough Republican votes over to the same side.  That’s the frame they wanted to work from.  They upped the bid and I’m seeing them.

Cross-posted at SquareState.

Cap and Trade Expenses Overblown

Critics (ideologically driven climate change deniers, mostly) have said that a carbon cap and trade program is too expensive (additional posts on this to follow).  One critical fact these short-sighted do-nothings are purposefully not talking about is that we have already spent billions on the effects of global warming, and it will only get worse.  Indeed, if the deniers have their way and we do nothing, the expenses on our society, what I will start terming the Cons’ Climate Tax, will get much, much worse.

I submit the following three examples for consideration:
- We have lost $1.3 billion as a result of crop loss from Georgia’s drought in 2007.
- It cost $300 million to repair rail transportation after Hurricane Katrina.
- We spent $272 million in 2007 as a result of increasing flood damage.

Those examples don’t include droughts in the rest of the country, wildfires, loss of viable timber, etc.

Is that not convincing enough? Okay, how about this: Four global warming impacts alone — hurricane damage, real estate losses, energy costs, and water costs — will come with a price tag of 1.8% U.S. GDP, or almost $1.9 trillion annually (in today’s dollars) by 2100.  The total cost will cost 3.6% of U.S. GDP.  Contrast that with the cost of a cap and trade program: The median projected impact of climate policy is less than one-half of one percent of U.S. GDP for the period 2010-2030, and under three-quarters of one percent through the middle of the century.

A growing body of studies are clearly demonstrating the damage the Cons’ Climate Tax would introduce to our society.  Unsurprisingly, their concern over deficit spending when it comes to American interests is as false as anything else they’re “concerned” about.  If they were concerned with the costs we’re passing along to future genertions, they would whole-heartedly embrace a carbon cap-and-trade program.  We can spend a few hundred billion dollars for a few years now and alleviate future climate change impacts.  Or we can push this problem off to the next generation and they can pay $4 trillion annually to deal with the effects.

But every time a Con gets to talk to the corporate media, they should be required to explain why taxing future generations for health care isn’t alright, but taxing them for climate change (or the occupation of Iraq or ever-increaing war budgets) is.  Either they’re fiscal hawks or they’re talking point recorders.  Talking point recorders don’t have any business deciding policy.

Four-Corners Tree Die-Off Tied To Global Climate Change Drought

This post will cover a lot of ground.  I’m writing it having just read a PNAS paper from 2005 about a massive vegetation die-off event being tied to global climate change-type drought in the four-corner states.  I have been thinking that such a study should be done as I read and learned about the various pine beetle epidemics afflicting Western North America.  The paper, “Regional vegetation die-off in response to global-change-type drought“  contains the kind of information that is critical in piecing a number of different threads together to weave a coherent story.  The results contained within the paper, which can also be seen at this PNAS website,  provide a profound message about the impacts of climate change.  Such impacts have already occurred.  As I’ve written recently (here and here, for example), they are growing in number and intensity.  We ignore them at our (and the Earth’s) peril.

A series of big messages I got from this paper can be summed up as follows.  With human-forced climate change, warmer droughts are predicted to occur more often.  One such drought has already occurred (and could be continuing to occur) in the southwestern U.S.  That drought has had a profound impact on a large region’s worth of vegetation.  That impact came in two waves: the drought weakened the vegetation which then fell to the beetle epidemic.  The beetles were able to spread due to the warmth that characterized this drought.  With this and other region-wide die-offs, the potential for large changes in carbon stores is real we will face with their consequences.  As a result, carbon-related policies must be prepared to take such die-offs (and their after-effects)  into account.  The failure of region-wide ecosystems, a disaster on its own, would also present a real danger to our society.

The paper identifies regional-scale mortality of overstory trees.  Such events alter ecosystems and land surface properties for decades.  Greenhouse forcings are expected to amplify the periodic, cooler droughts found in previous climate regimes.  The drought that has occurred across the southwest since 2000 offers evidence about how those forcings manifest.  [On a short tangent, the widespread, severe drought in Australia provide additional evidence.]  This paper focused on a Piñon pine die-off.  Additional trees act as overstory species across the four states studied.  At this time, I’m not aware of similar studies detailing the greenhouse-forcing-drought-beetle-die-off relationship as it relates to those species.  It is something I will look for after writing this.

There is one figure in this paper that I want to draw particular attention to:

This figure shows annual average temperatures and precipitation values for all the stations included in the study.  The yellow-shaded vertical bands point out two regional-scale droughts – the first in the 1950s and the second in the early 2000s.  In particular, I want to draw attention to the rise in average annual temperatures from the mid-1990s to the mid-2000s (top panel): from ~10.7C to 12.3C.  Combined with the corresponding drop in precipitation from 380mm to ~250mm, this is what the authors have characterized as a global-change-type drought.  It contrasts with the 1950s drought by being statistically warmer to a significant level.  The bottom two panels also deserve some attention.  Two of the last four years in the study exhibited maximum average annual temperatures at the 90th percentile (panel c).  Three of the last four years in the study exhibited minimum average annual temperatures well above the 10th percentile (panel d).  That information isn’t available from the top panel

The reason I draw attention to the temperature rise in particular is the warning it provides about anticipated future warming across the region as the climate continues to respond to greenhouse forcing.  Under scenarios now considered likely with the “warming in the pipeline”, temperatures across this region are expected to rise another 2-10C.  As I wrote above, this paper demonstrates the impacts that warming has on dominant vegetation types: water stressing the plants and allowing bark beetle infestations to spread unabated.  With even more warming, what effects will ecosystems in the region experience?  I’ve written before about the bark beetle problem affecting the higher elevations of Colorado and other regions across the Rocky Mountains (see list below).  Those trees were impacted in a similar fashion that the Piñon trees were in this study.  How many additional species will be stressed to the point that they will also experience region-wide die-offs?  Under those same climate change scenarios, annual precipitation is expected to continue to decrease.  That decrease will be for all purposes permanent as far as humans are concerned.  Desert-level precipiation amounts are quite possible for hundreds of years.

Now look at the graph more closely.  We’ve seen the devastating effects just a small quantitative amount of warming has already had.  That’s one of the real dangers of climate change: ecosystems are quite used to the climate of the 20th century (in a larger sense, that of the past few thousand years).  There is no way of accurately foretelling how those ecosystems will respond to a significantly different climate, which we might already have entered into.  The die-offs I’ve seen and read about; the shifting climate and ecosystems zones I’ve seen evidence of tell me that the climate at the end of the 21st century could be quite different than the one of the 20th century.

Expanding on this a bit: at what stage would prairie grass die-off?  I can hear the denialist line about tree die-off and small animal die-off not being a big deal and not indicative of climate change.  The level of tree die-off discussed in this paper was unprecedented in scope: all ages, all sizes were affected.  Beyond that though, I wanted to come up with a scenario that would provide more visceral evidence of climate change impacts on human society.  If grass or hay or the like experienced a regional die-off due to an expanding, long-term warm drought, what would we do?  If cattle started dying by the millions due to water stress and epidemics, would more people take notice?  I have to think so.  I hope it doesn’t get to that level, but it might before we all aggressively look for greenhouse forcing solutions.

One additional question I have is what story does the post-2004 data tell?  I will look for additional, related studies to this one to fill out the scene.  It was somewhat surprising that this study was published in 2005 .  Nobody I’ve spoken to about the ponderosa pine die-off was aware of this paper – which is part of the reason I’m writing about it.  If anyone is aware of such a study, I’m all ears.  Otherwise, I’ll write something up on whatever I find.

Cross-posted at SquareState.
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Here is a list of some of the bark beetle epidemic posts I’ve written:

Western Forests Could Become Carbon Source, Not Sink

2008 Pine Beetle Kill: 400,000 acres in CO

Healthy Forests/Vibrant Communities Act of 2009

Wilderness Society’s Aerial Investigation of CO Pine Beetle Kill

Beetle Killed Trees May Be Allowed to Burn

Battling the Mountain Pine Beetles

Catastrophic beetle kill in Colorado