Category — Climate sensitivity
The scientific findings of the human influence on the climate system have been, and perhaps will always be, a mixed bag. Assuming strong positive feedback effects, and thus a high climate sensitivity, it certainly can be argued that the bad outweighs the good. But if feedback effects are more neutral, the sign of the externality flips from negative to positive given that, on net, a moderately warmer, wetter, and CO2-fertilized world is quite arguably a better one.
Earth Day 2012 yesterday brought forth predictable cries of doom-and-gloom. But there are plenty of positives on closer inspection on the climate front, developments which have undoubtedly spilled over into making the earth a better place for humanity at large.
Here is my Top 10 list of positive climate developments based on the recent empirical data and the latest scientific literature:
April 23, 2012 45 Comments
“A collection of research results have been published in the peer-reviewed scientific literature in recent months that buoys my hopes for a low-end climate sensitivity.”
One of the key pieces to the anthropogenic climate/environment change puzzle is the magnitude of the earth’s climate sensitivity—generally defined as the global average temperature change resulting from a doubling of the atmospheric concentration of carbon dioxide (CO2).
One of the reasons that the “climate change” issue is so contentious is that our understanding of climate sensitivity is still rather incomplete. But new research efforts are beginning to provide evidence suggesting that the current estimates of the climate sensitivity should be better constrained and adjusted downwards. Such results help bolster the case being made by “lukewarmers”—that climate change from anthropogenic fossil-fuel use will be moderate rather than extreme, and that an adaptive response may be more effective than attempts at mitigation.
In its Fourth Assessment Report (AR4), released in 2007, the Intergovernmental Panel on Climate Change (IPCC) provided this general guidance on the climate sensitivity:
[The equilibrium climate sensitivity] is likely to be in the range 2°C to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement of models with observations is not as good for those values.
In IPCC parlance, “likely” means an expertly assessed likelihood of an outcome or result with greater than a 66% chance of occurrence. “Very unlikely” means less than a 10% change of occurrence.
Visually, the IPCC’s assessment of the climate sensitivity based on its interpretation of the extant literature at the time of its assessment is shown in Figure 1. The IPCC routinely includes studies which conclude that there is a greater than a 10% possibility that the true climate sensitivity exceeds 6°C and some which find that there is a greater than 5% possibility that it exceeds 10°C.
Fig 1. Climate sensitivity distributions retained (and in some cases recast) by the IPCC from their assessment of the literature. Note that the distributions fall off much more slowly towards the right, which indicates that the IPCC considers the possibilities of the climate sensitivity having a very large positive value (that is, a large degree of global temperature rise for a doubling of the atmospheric carbon dioxide concentration) to be not inconsequential (source: IPCC AR4).
If the true value of the climate sensitivity does turn out to exceed 6°C, then we will be in for what will probably turn out to be fairly disruptive climate change. Heck, even if the climate sensitivity lies much above 4.5°C, coming climate change will be substantial. I for one, would hope that it lies below 3°C, and actually turns out to be closer to 2°C.
A collection of research results have been published in the peer-reviewed scientific literature in recent months that buoys my hopes for a low-end climate sensitivity. Here are some salient quotes. [Read more →]
March 19, 2012 21 Comments
“Mounting evidence [of lukewarming] begins to start to make you wonder whether there is some fundamental problem between climate models and reality.”“To me, the most significant thing that the Climategate emails show is that the deck is stacked against the publication of research results that are critical of the established scientific consensus, and the skids are greased for papers that run in support…. Not a good situation for the advancement of science.”
“Lukewarmers” are those scientists (and others) who believe the balance of evidence is middling between “climate alarmists” (who tend to think that the global temperature rise will lie in, or even exceed, the upper half the IPCC’s 1.1°C–6.4°C range of projected temperature rise this century) and ultraskeptics, or “flatliners” (who tend to think that the addition of human-generated carbon dioxide has virtually no impact on global temperatures).
Lukewarmers have found the world to be a lonely place. But favor (think physical processes of global climate) smiled for us in 2011. Several scientific studies produced results, when considered in combination, provide evidence that the general warming of the earth’s climate is proceeding at a rate that lies in the lower half of the IPCC’s projected temperature change during the 21st century.
And with a low-end temperature rise comes along low-end impacts. Seemingly good news for all!
First, let’s review the global average temperature, both at the surface, and in the lower atmosphere since 1979—the year that satellite observations of the temperature from the lower atmosphere become reliably available, and pretty near the beginning of the second warming episode of the 20th century. [Read more →]
January 19, 2012 39 Comments
The numbers are in for this year’s summer sea ice extent in the Arctic Ocean. By most measures the ice loss in 2011 came in a close second to the current and still record holder, 2007.
But the failure to set a new record for the least amount of summer Arctic sea ice observed during the satellite era (which begins in 1979) has done little to alter the overall picture of what is going on there. Summer sea ice has been in decline in the Arctic Ocean since, conservatively, the mid-20th century, and it has been picking up steam. And sea ice declines in the Arctic are now pretty clearly discernible in the other seasons as well. (What has been going on around Antarctica is a different story).
But for those who lose sleep at night over the implications of the Arctic sea ice loss to both the local, regional, and global environments, there is a silver lining. The rapid loss of sea ice, coupled with the slowed rate of global temperature increase, is a potential indicator that the earth’s climate sensitivity may be lower than climate model determinations. If true, this means less warming per future unit of greenhouse gas emissions.
Sleep easier. [Read more →]
October 11, 2011 5 Comments
“In any case there is an irony: environmental policy in the name of countering the human influence on macro climate is creating a substantial human influence on micro climate. If the natural climate is optimal, as some but not all ecologists believe, then industrial wind turbines add to the problem of man versus nature.”
I have long heard of micro-climates, isolated areas that have slightly different weather patterns than the surrounding larger area. I best remember hearing of the micro-climate of Northern California’s Napa Valley, a micro-climate that makes the area so good for growing grapes.
For the last several years, Somnath Baidya Roy has been pushing the concept that wind farms can affect the weather. While at the department of civil and environmental engineering at Duke University, Roy said:
“Large wind farms can significantly affect local meteorology.” He studied these massive machines and believes wind farms can actually impact our weather because wind turns the blades of the turbine around a rotor, which helps generate electricity the blades create a lot of turbulence in the wake.”
Roy also said at that time:
“It’s something like the wake from the propeller of a boat. Now this added turbulences mixes air up and down and creates a warming and drying effect near the ground.” He says the affects can be felt for miles and could have an impact on air conditioning costs and more money may have to be spent on irrigation of nearby crops.”
Wind farms tend to impact the weather more at night, which is when the wind is usually stronger and the most energy is generated.
WHAT THEY FOUND: Large groups of power-generating windmills could have a small influence on a region’s climate. All large wind turbines disrupt natural airflow to extract energy from wind. During the day, the effects from the disturbed airflow are negligible, since natural turbulence mixes the lower layers of the atmosphere. But the researchers found that in the predawn hours, when the atmosphere is less turbulent, a large windmill array could influence the local climate, raising temperatures by about 2 degrees Celsius (about 4 Fahrenheit) for several hours. The rotating blades could also redirect high-speed winds down to the Earth’s surface, boosting evaporation of soil moisture.
“Wind Farms Impacting Weather: Environmental Engineers Detect Turbines’ Turbulence Effects” Science Daily, 2005 October 1.
Roy is now atmospheric sciences professor at the University of Illinois at Urbana-Champagne and is continuing his research, but with some different findings. A study “Impacts of wind farms on surface air temperatures,” published in late 2010 in the Proceedings of the National Academy of Sciences, written by Roy and Justin J. Traiteur now shows: [Read more →]
August 2, 2011 3 Comments
[Editor’s note: The following material was supplied to us by Dr. Richard Lindzen as an example of how research that counters climate-change alarm receives special treatment in the scientific publication process as compared with results that reinforce the consensus view. In this case, Lindzen's submission to the Proceedings of the National Academy of Sciences was subjected to unusual procedures and eventually rejected (in a rare move), only to be accepted for publication in the Asian Pacific Journal of Atmospheric Sciences.I, too, have firsthand knowledge about receiving special treatment. Ross McKitrick has documented similar experiences, as have John Christy and David Douglass and Roy Spencer, and I am sure others. The unfortunate side-effect of this differential treatment is that a self-generating consensus slows the forward progress of scientific knowledge—a situation well-described by Thomas Kuhn is his book The Structure of Scientific Revolutions. –Chip Knappenberger]
- Richard S. Lindzen
The following is the reproduction of the email exchanges involved in the contribution of our paper (Lindzen and Choi, “On the observational determination of climate sensitivity and its implications”) to the Proceedings of the National Academy of Sciences. The editor of the PNAS follows the procedure of having his assistant, May Piotrowski, communicate his letters as pdf attachments.
These attachments are part of the present package. Attachment1.pdf is simply a statement of PNAS procedure. Note that members of the NAS are permitted to communicate up to 4 papers per year. The members are responsible for obtaining two reviews of their own papers and to report the reviews and their responses to the reviews. Note, as well, that rejection of such contributions by the Board of PNAS is a rare event, involving approximately 2% of all contributions.
The rejection of the present paper required some extraordinary violations of accepted practice. We feel that making such procedures public will help clarify the peculiar road blocks that have been created in order to prevent adequate discussion of fundamental issues. It is hoped, moreover, that the material presented here can offer the interested public some insight into what is involved in the somewhat mysterious though widely (if inappropriately) respected process of peer review.
This situation is compounded, in the present example, by the absurdly lax standards applied to papers supportive of climate alarm. In the present example, there existed an earlier paper (Lindzen and Choi, 2009) [we covered that paper here -CK], that had been subjected to extensive criticism. The fact that no opportunity was provided to us to respond to such criticism was, itself, unusual and disturbing. The paper we had submitted to the PNAS was essentially our response which included the use of additional data and the improvement and correction of our methodology. [Read more →]
June 9, 2011 83 Comments