Climate Change: Degrees of Trepidation

by Sidney G. Winter on January 23, 2012

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There is an ongoing, intense and highly politicized discussion going on in the U.S. about the reality and implications of climate change.   With Jon Huntsman’s withdrawal from the race for the Republican nomination, there is now no candidate remaining in that race who squarely affirms that climate change is a reality, much less one who concedes that human activity is causing it, or that some policy response might be needed.   Of the candidates who contended in the South Carolina primary, one (Santorum) is a steadfast denier, while Gingrich and Romney are recent converts to the skeptical position.  The possibility that the latter might revert to their former stance is viewed with alarm by those whom they now court and as a source of solace for those who hope that even a Republican victory in November might not directly imply a disastrous turn in energy and climate policy.  It is increasingly clear that climate change has turned into an ideological litmus test.

There are many indications of the dismal state of the discussion, assuming it deserves to  be called that.  Last summer, an article in  Science, reported on an effort to require school science teachers in grades K-12 to approach climate change in a “balanced” way – an effort that parallels, in its political appeal and style, earlier efforts to get evolution vs. creationism taught in a “balanced” way.[i]   It seems that  a substantial segment of the American polity lumps climate change with evolution, and sees both as entangled with questions of religious belief.   For  poignant testimony on what it’s like to be “in the middle” in such an environment, see this interview with Katherine Hayhoe, who describes herself as a Christian and a climate scientist; she was scheduled to provide a climate change chapter for a Newt Gingrich book –  until the plan for such a chapter was abandoned; see also  http://climateforchangethebook.com/

 As this is written, the Obama Administration has announced opposition to the proposed Keystone Pipeline – and thereby provoked a chorus of indignant response, invoking the cause of “jobs” and that perennial will-of-the-wisp, “energy security” or “energy independence.”  Critics of the proposal argue that it would produce  damage to the environment going well beyond that which would attend  the use of an equivalent amount of crude oil from existing sources.  The Administration, while apparently responding to environmentalist concerns about the project, has yet to articulate opposition in those terms. 

This polarization and politicization is obviously a direct threat to hopes for prudent policy on climate change, but it may also have a significant indirect consequence:  It may tend to pull the attention of informed and concerned individuals away from some very important questions  — questions for which answers are indeed quite  speculative, or  non-existent at this time.  This note represents  an effort to expand the domain of the discussion to its proper size, allowing the reader to find his or her own preferred position on the trepidation scale – and also to calibrate what others are saying.  For that purpose, consider this scale:

0. The Earth Isn’t Getting Warmer.   It is widely acknowledged, even by many  “deniers” and “skeptics”, that there is massive evidence against this position. [ii] Nevertheless, the zero position still has strident advocates.  More important,  it seems to serve as a benchmark or “null hypothesis,” leading to over-emphasis on the (established) fact that the planet is warming and an under-emphasis on future-oriented  questions such as, “How much warmer is it going to be ten years from now?”

1.  The warming may be real, but it is not human-caused (“anthropogenic”); and in particular, it is not caused by the accumulation of greenhouse gases (GHGs) in the upper atmosphere.

      a. Rather, the warming is a typical short-term climate fluctuation and may soon go away.

      b. Or, the warming may be a longer-term phenomenon – e.g. because we are still emerging from the last Ice Age — but there is no plausible role for public policy in coping with it.

2.  The question of whether the warming is real, long-term and anthropogenic is far from settled.  It would, therefore, be premature to undertake public policy interventions that could be unnecessary or conceivably counterproductive, but can reliably be assumed to be expensive – and to expand the role of government.   More evidence is needed.

3.  It is reasonable to conclude on the existing evidence that global warming is a real, long-term problem caused by GHG increases that are in turn attributable, in various ways, to human activity — but it is developing relatively slowly, is primarily a matter of higher temperatures and slowly rising sea levels, and can be countered by relatively cheap and/or slowly-evolving  policy interventions aimed primarily at CO2  emissions.  We can expect that such interventions that will ultimately be made, as evidence becomes clearer and the political consensus swings in favor of intervention.   

Prominent economists in the climate change debate (Nicholas Stern, William Nordhaus) seem to take essentially this position.  Their note of urgency relates to the initiation of a more balanced  policy trajectory, not to where the current trajectory is headed – and how fast.

4.  There are important dimensions of the problem that are more immediate and severe than rising  global temperatures and sea levels; in fact they are currently consequential.  The long-standing prediction of “extreme weather events” as a principal implication of climate change is being borne out right now – particularly in the form of the increased frequency and severity of floods, droughts, hurricanes and tornados.[iii]  Although attributing an individual, local weather event to climate change is an abuse of the concept of “climate” (meaning average patterns of weather, or the systemic determinants underlying those patterns), a new local record is a valid statistical indicator of climate change in the sense that it would be a low probability event if the climate were stable.  A flurry of new records is a strong indicator of change, and the more so if long-standing records are being broken by substantial margins – and that is exactly what has recently been happening, globally.   When a particular locality has a standing record for high temperature at a given day of the year, and it is then broken by several degrees (as happened many places  in the summer of 2011, including Washington), it is reasonable to ask how many years of that kind of record-setting it takes before things are really serious.[iv]  

5.  The question of how climate change will unfold in the future is subject to large uncertainties in both directions.  The uncertainties on the optimistic side are the thin reed on which rests the rational case for “more evidence is needed.” There are also, however, major uncertainties in the unfavorable direction.  A number of known feedback mechanisms could accelerate the change, possibly pushing outcomes in the next few decades beyond the bounds of the least favorable scenarios examined in the most recent report of the Intergovernmental Panel on Climate Change (IPCC). 

These mechanisms include ones that are relatively calculable for the climate modeling community, such as the effects on the Earth’s albedo of the dwindling of the polar ice caps, and the increasing levels of water vapor (the most important GHG) in the atmosphere as a direct consequence of warming.   In other cases, the mechanism is well understood but the likely pace of its working and the severity of its consequences is hard to estimate.  An example of the latter is the prospective release of substantial amounts of methane from the thawing of the Arctic permafrost.  Methane is a GHG with about 20 times the potency  of CO2, but a half-life in the atmosphere of around 15 years, as opposed to 30-100 years for CO2.  There is a massive amount of methane in the tundra and Arctic seabed, mostly “frozen” in a water molecule cage (methane hydrates).  Warming releases the methane from the cage.   For a recent report on the methane threat see http://www.nytimes.com/2011/12/17/science/earth/warming-arctic-permafrost-fuels-climate-change-worries.html?pagewanted=all, which reports an estimate that thawing in arctic regions could ultimately produce an increase in carbon emission rates of as much as 15% over current levels currently caused by human activity.  See also Hendry, forthcoming, cited in note 4.

There could also be important adverse feedback effects from interventions intended to address the causes of warming.   At present, the warming effect of the GHG is offset to a substantial extent by particulates in the atmosphere, such as those from coal burning, forest fires and jet contrails, as well as volcanic eruptions.  Some have argued that this effect is large and inadequately accounted for in the climate models.  If so, actions that reduce the amount of particulates in the atmosphere (for whatever reason) may reveal the true strength of the underlying warming trend and produce further acceleration via the other mechanisms of positive feedback.  

In addition to potential positive feedback mechanisms that are difficult to assess, there are what might be called “lurking trends” — contributions from factors that are rising from a low base to levels that may be highly consequential.    An example of such a trend is the increase in nitrous oxide emissions, which is driven in part by the increased use of nitrogen-based synthetic fertilizers in developing countries.  Nitrous oxide is a GHG that is 300 times more potent than CO2 by weight, and as of 2004 accounted for about 8% of anthropogenic  GHG emissions in CO2  – equivalent terms (IPCC 2007).

6.  The perspective described above as degree 3 rests on hopes that corrective policy will allow us to avoid a climate catastrophe, assuming that such a catastrophe is now threatening.  The realism of these hopes is open to question, however, and the contrary hypothesis deserves serious attention.  The contrary hypothesis is this:  While the threatening trend of the climate may ultimately be reflected in widespread recognition of the need for intervention, the potentially favorable effect of such recognition may be overbalanced by the increasing difficulty of taking action.   In a world of finite resources and limited budgets, climate policy competes with many other needs, almost all of which are expressed with relative strength derived from their apparent immediacy.  In particular, interventions aimed at the long run situation will compete with a range of demands arising from climate-related emergencies – from relieving famine in Africa to the response to flood and tornado damage in the American Midwest, and on to enhanced efforts to control national borders against the onslaught  of desperate  immigrants that climate change produces.  Extreme weather events are already destroying productive assets, and relief and reconstruction efforts are already absorbing significant resources.  (Some of this reconstruction may well be wasteful, as authorities fail to absorb the fact that the status quo ante is no longer sustainable, even if it can be restored temporarily.   See, arguably, New Orleans after Katrina.  Where there is room for policy, there is room for mistaken policy.)

This last point illustrates a broader one:   Recognizing the need for action is one thing, but identifying the action that is appropriate is quite another.  Increasing acceptance of the reality of anthropogenic climate change would not necessarily spell the end of the intense politicization of the issues; it might just shift it to new domains.  The extreme complexity of the problem and the high stakes involved make it quite appropriate to direct intense scrutiny to proposed policies — provided that recognition of this need for  scrutiny does not amount to a tacit vote for the motion to “postpone indefinitely.”

Political and social stresses of a much larger scale may arise as a result of human migration forced by climate change and of international tensions born of the vast disparities in impact and causal responsibility.  There are many very angry people in the world today, and the reasons for their intense anger  — mostly directed at the prosperous, predominantly Christian, West – sometimes seem unclear, at least to those favorably situated in advanced countries.  As climate change proceeds, there will be a great many more angry people and “rational” reasons will become clearer and clearer.  Some of those angry people will have, or could well have, weapons of mass destruction at their disposal.   Of course, using WMD on the “guilty” would not be an instrumental approach to the solution of their actual problem, but psychology, criminology  and history yield little assurance that considerations of instrumentality are powerful shapers of anger-driven  behavior. 

7.  Modern human civilization is at risk.[v]  To provide a benchmark for discussing the risk, I define a “collapse of modern civilization” as a sequence of events in which the global division of labor, and in particular the global food system, suffers a serious breakdown, and as a result the human population of the planet declines over a few decades to a point 30% or more below its previous peak.  As far as I know, such an event would be a disaster that is unprecedented in the history of the species back to its early days, though when viewed in global perspective it is perhaps comparable in magnitude  to the worst outbreaks of bubonic plague (which were more severe regionally, but none of which was itself global).  For the human population as a whole, there may be no precedent  this side of the long “volcanic winter” caused by the Mt. Toba eruption of about 70,000 years ago, which some claim to have reduced the population of modern humans to about 10 to 15 thousand, from a previous peak in the millions.  Thus, my benchmark collapse is from this point of view a very extreme event.  Yet, `applying the 30% decline to a current population of about 7 billion, we come to 4.9 billion.  Somewhat startlingly, this means that the collapse resets the human population clock back only to about 1987.  On an evolutionary timescale it is a hiccup, a dip far surpassed by commonplace fluctuations in animal populations (which include frequent extinctions, of course).[vi]  That is not to say, however, that the human enterprise would quickly return to business as usual – we should expect, and hope, that it would not.

The elements of plausible collapse scenarios are available in the discussion above.  To get evocative  imagery for the presentation, we could turn to the drought-based famine in Somalia and juxtapose it with the story of the Russian embargo on grain exports, which was imposed in 2010 in response to harvest failures caused by drought.    What happens if, under worsening drought conditions in the grain-producing regions of the world,  all the major exporting countries decide to block exports, taking the view that high market prices do not cover the full costs of allowing scarce food to leave the country?  (Meaning specifically, the “full costs” to incumbent regimes for whom domestic unrest brought on by high food prices is a concern.)

While the plausibility of scenarios can be argued, there is one very clear fact that is of crucial importance.   The lag in the climate response to a major policy intervention directed at GHGs would be enormous.  If we could throw a switch right now and stop the further growth of GHG emissions,, global temperatures would continue to rise for decades, with, very likely, a temporary  overshoot of the steady state global temperature that would perhaps ensue.   Before those decades of response lag can begin, we have to come to a degree of collective consensus (across the globe) adequate to support a policy portfolio of that effectiveness, and then phase in that policy.  It is probably optimistic to assess the latter process as requiring only another decade.  As for the consensus-building phase, progress seems to be stuck in a political rut, at least in the U.S., and the timing of a resumption is uncertain.  In the pre-intervention decades, atmospheric GHG concentrations will continue to rise, and so will the temperature. 

The overall system — the climate system plus the various human systems affecting it — has enormous inertia.  Right now, it has a moderate velocity in a catastrophic direction.  The most important question, therefore, is not about the details and timing of the catastrophe, it is what might happen to check the existing velocity and prevent the catastrophe.   Perhaps some currently unrecognized feature of the climate system will kick in and stabilize the temperature at acceptable levels.   Perhaps an upsurge of volcanism, or a quieting of the Sun, will defer the problem for centuries. 

 Beyond the “collapse of modern civilization” scenario characterized above, there are obviously less “favorable” outcomes.  A crucial question is whether the combined system has a stable equilibrium point where the human population is still greater than zero.  A decline in the human population of the planet would by itself tend to reduce the velocity toward catastrophe, quite apart from the effects of any policy measures.  If the lag in feedback from population decline and/or collective  action to climatic consequence were three or five years, it would be  hard to imagine that h. sapiens is not sapient enough to ward off an extinction-level catastrophe, even if that required totally unprecedented achievements of collective organization.  But if that lag is thirty or fifty or years or more – it becomes hard, instead, to imagine where the basic political energy for adequate corrective action would come from.  There is some combination of strong short-term attractiveness and strong but long-delayed adverse consequences that almost certainly constitutes a suicide pill for humans.  At the individual level, we “sapient” humans succumb to such temptations on a regular basis.  At the collective level … it is now an open question as to what  precise temptations the environment is offering us, and what our response will be.

 

 

____________________

The relatively informed part of the current public discussion seems to me to be concentrated at around degrees 3 and 4 on my scale.  In a way, that is reasonable, because that is where the relatively solid evidence is, including the part of the evidence that can be experienced directly by individuals.  Beyond that, we have projections and speculations (like mine above), we have advocacy of various kinds – and, most importantly, we have the work of the climate modelers.   The modelers are much concerned with establishing and defending the scientific quality and integrity of their work – which is appropriate, given that they are scientists, and highly understandable, given the attacks made upon them and their work.   This legitimate focus contributes, however, to the unsatisfactory state of the overall discussion:   The crucial component of human values is missing from the scientific conclusions, or left largely implicit.  When conclusions are stated that do rest on value premises, they are typically stated with timidity or bureaucratic equivocation.[vii]   For example, the term “uncertainty” in the scientific accounts (e.g., the IPCC Fourth Assessment) almost always carries the connotation “don’t take this too seriously”  or “not a reliable basis for action.”  In the context of policy decision, however, some uncertainties need to be taken very seriously indeed — and taken to be, as such, a basis for preventive action.

 In my view, the current trajectory and velocity of the climate problem are morally unacceptable in the extreme – because of the risk, not the certainty, that a large scale catastrophe will ultimately ensue, a catastrophe that could ultimately threaten the entire human enterprise on the planet.   We (adult humans today) are not entitled to risk imposing such burdens on future generations, or much less to risk  expunging those generations from potential history.  We are particularly not entitled to do so merely for the sake of trying to maintain standards of living at high levels unseen by our own grandparents.  But that is not a scientific conclusion, and even the more limited problem of assessing the risks in fully objective terms very difficult.   It is not the role of climate scientists, as scientists, to put it all together.   But whose role is it, and how much climate science do they know?




Endnotes

[i] “Climate Change Sparks Battles in Classroom,” Science 333: 688-689.

[ii] There is a pamphlet entitled “The Skeptic’s Handbook,” by science writer Joanne Nova, which can be found on line.  The skepticism presented is focused almost 100% on the claim that warming is anthropogenic and involves carbon, with the refrain “Something else is causing the warming.”  According to the Science  article just mentioned, this pamphlet was mailed to “the presidents of the country’s 14,000 public school boards” by the Heartland Institute – an organization “which has received significant funding from Exxon-Mobil.”

[iii] The apparent paradox of “floods and droughts” is akin to the apparent paradox of increased snowfall due to global warming.  In brief, the level of the temperature is relevant as well as the increase.  Where the temperature level remains low enough for snow to be possible, the temperature increase is reflected in more water vapor in the atmosphere, which precipitates as snow.  Similarly, where air temperature is high enough to produce water uptake from the surface to the atmosphere, higher temperature produces more uptake, i.e. more drying.  When the air reaches latitudes where it is cool enough to produce condensation, the water comes out of the atmosphere as rain or snow.  A sustained warming trend will eliminate the snow, and a long time after that, the rain. 

[iv] Example:  At Dulles International Airport, near Washington, daily temperature records go back to 1963.  The record for July 22 was 98 degrees, set in 1983, and equaled in 1988.  In 2011, that record was re-set to 105 degrees.  http://www.washingtonpost.com/blogs/capital-weather-gang/post/historic-heat-wave-recap-of-washington-dc-2011-sweat-ceiling/2011/07/25/gIQAPrbwYI_blog.html.

[v] By “modern” human civilization, I mean a civilization based ultimately on the achievement of very high labor productivity in agriculture, releasing most of the population to pursue goals beyond securing adequate food.  Regional populations currently supported by subsistence agriculture are also at risk – but not so much from the collapse of the modern division of labor as from the direct impact of the climate change on their means of securing food.  See, for example, Somalia today, and the recurrent terrible problems in the Sahel – which will almost certainly get worse.  Because the subsistence regions are mostly tropical or sub-tropical, they are unlikely to have good luck in the climate change draw and are probably at greater and more immediate risk than the rest of the world.

[vi] In “Climate Change: Lessons for our Future from the Distant Past,” David Hendry points to the evidence for a major role for climate change in the mass extinction events of the past half billion years, noting that it is above all the pace of change that has in these episodes presented  the insurmountable evolutionary challenge to many life forms. The paper also contains a valuable review of much of the relevant background knowledge, and directs attention to the limitations of  existing analytical methods for studying change.  (Forthcoming in The Political Economy of the Environment, Dietz, Michie and Oughton, eds., Routledge )

[vii] See the less-than-resounding conclusion of the IPCC 2007 synthesis report, quoted at the end of this document. 

Robust findings of the IPCC

Some planned adaptation (of human activities) is occurring now;

more extensive adaptation is required to reduce vulnerability to climate

change. {WGII 17.ES, 20.5, Table 20.6, SPM}

 

Unmitigated climate change would, in the long term, be likely

to exceed the capacity of natural, managed and human systems to

adapt. {WGII 20.7, SPM}

 

— Climate Change 2007: Synthesis Report (IPCC Fourth Assessment Report),

    p. 73 (final page).

 

Endnotes

[1] “Climate Change Sparks Battles in Classroom,” Science 333: 688-689.

[1] There is a pamphlet entitled “The Skeptic’s Handbook,” by science writer Joanne Nova, which can be found on line.  The skepticism presented is focused almost 100% on the claim that warming is anthropogenic and involves carbon, with the refrain “Something else is causing the warming.”  According to the Science  article just mentioned, this pamphlet was mailed to “the presidents of the country’s 14,000 public school boards” by the Heartland Institute – an organization “which has received significant funding from Exxon-Mobil.”

[1] The apparent paradox of “floods and droughts” is akin to the apparent paradox of increased snowfall due to global warming.  In brief, the level of the temperature is relevant as well as the increase.  Where the temperature level remains low enough for snow to be possible, the temperature increase is reflected in more water vapor in the atmosphere, which precipitates as snow.  Similarly, where air temperature is high enough to produce water uptake from the surface to the atmosphere, higher temperature produces more uptake, i.e. more drying.  When the air reaches latitudes where it is cool enough to produce condensation, the water comes out of the atmosphere as rain or snow.  A sustained warming trend will eliminate the snow, and a long time after that, the rain. 

[1] Example:  At Dulles International Airport, near Washington, daily temperature records go back to 1963.  The record for July 22 was 98 degrees, set in 1983, and equaled in 1988.  In 2011, that record was re-set to 105 degrees.  http://www.washingtonpost.com/blogs/capital-weather-gang/post/historic-heat-wave-recap-of-washington-dc-2011-sweat-ceiling/2011/07/25/gIQAPrbwYI_blog.html.

[1] By “modern” human civilization, I mean a civilization based ultimately on the achievement of very high labor productivity in agriculture, releasing most of the population to pursue goals beyond securing adequate food.  Regional populations currently supported by subsistence agriculture are also at risk – but not so much from the collapse of the modern division of labor as from the direct impact of the climate change on their means of securing food.  See, for example, Somalia today, and the recurrent terrible problems in the Sahel – which will almost certainly get worse.  Because the subsistence regions are mostly tropical or sub-tropical, they are unlikely to have good luck in the climate change draw and are probably at greater and more immediate risk than the rest of the world.

[1] In “Climate Change: Lessons for our Future from the Distant Past,” David Hendry points to the evidence for a major role for climate change in the mass extinction events of the past half billion years, noting that it is above all the pace of change that has in these episodes presented  the insurmountable evolutionary challenge to many life forms. The paper also contains a valuable review of much of the relevant background knowledge, and directs attention to the limitations of  existing analytical methods for studying change.  (Forthcoming in The Political Economy of the Environment, Dietz, Michie and Oughton, eds., Routledge )

[1] See the less-than-resounding conclusion of the IPCC 2007 synthesis report, quoted at the end of this document. 

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