Climate Science: Roger Pielke Sr. Research Group News

Last year, I testified before a House Subcommittee on the

Pielke Sr., Roger A., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy. Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp. [View PDF of Oral Summary].

I am pleased that my testimony was referred to in the Republican comment on the Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases Under the Clean Air Act issued by the Administrator of the Environmental Protection Agency (EPA). 

More importantly, the comments provide further documentation in the public record as to major issues with regulating CO2 and several other well-mixed greenhouse gases as pollutants. Of particular relevance to my expertise, the EPA Findings are not scientifically robust; e.g. see

Brief Overview Of Several Climate Science Research Findings

Comments On The EPA “Proposed Endangerment And Cause Or Contribute Findings For Greenhouse Gases Under The Clean Air Act”.

As I wrote in the last weblog listed above

“In conclusion, the EPA Endangerment findings is the culmination of a several year effort for a small group of climate scientists and others to use their positions as lead authors on the IPCC, CCSP and NRC reports to promote a political agenda.”

I look forward to reading how EPA responds to the issues that are raised in the comments by the House Members.

There is a very informative summary of a number of the issues raised on my website in a post on weblog The Resilient Earth by  Doug L. Hoffman on june 16 2009.  The post is titled

Seven Climate Models, Seven Different Answers 

The post is worth reading and their website should be bookmarked. The conclusion of their weblog states

“Earth’s climate system is amazingly complex and modeling is fraught with pitfalls and danger for even the most experienced computer scientists. No climate model predicted the current downturn in global temperatures, though many are now scrambling to predict possible decades of unchanging or cooling climate “within the general warming trend.” Still, climate science remains enthralled by its computerized playthings. I have to echo Professor Pielke’s question, how many years of wrong results are necessary before we reject the IPCC reports and the models they are based on?”

The plan to regulate CO2 by the EPA, and the intent of Congress and the President to introduce a “cap and trade” program for carbon emissions, in order to regulate climate, should require that the basis for these policy decisions be scientifcially robust.  It is essential to include all human climate forcings on climate (including land use/land change effects) in assessing the ability of their plans to actually alter climate.  They clearly have ignored doing this, and we will have a costly yet ineffective climate policy as a result.

SECOND UPDATE: See the May 20 2009 article by Jayne O’Donnell and James R. Healey in USA Today titled

“Safety could suffer if we boost mileage by making cars smaller”

Updated pm May 19 for clarity at the beginning of the first sentence of the paragraph below the bullets

Today, President Obama is announcing the establishment of a new car fuel mileage standard of 35.5 miles per gallon ( see Automakers, Obama announce mileage, pollution plan by Ken Thomas and Philip Elliot).  Their article includes the new framework for this standard where they report

“Historically, the program was a fleet average,” said Browner, who headed the EPA during the Clinton administration. “What we’re doing here is proposing standards for every category of car.”

 This increase in the standard could be achieved by one or more of the following:

• technology could improve the efficiency of the combustion process
• technology could provide/permit the use of alternative energy sources such as hybrid and electric engines
• vehicles could be made smaller and/or lighter

The first approach would use the current type of combustion engine and make it even more efficient than it is at present. The second method reduces tailpipe emissions of the combution products from the vehicle, although the emissions from the source of the energy (i.e. power plants) needs to be included in the assessment of mileage. The third approach could use lighter materials to build the cars and/or they could be made smaller.

I agree that the technology improvements in the first two bullets would be a win-win for both the environment and for the reduction of the import of foreign energy sources, and should be achievable without a reduction in safety.

However, if the approach is just to make cars smaller and/or lighter, the potential increase in injuries and deaths as a result makes this a poor approach; e.g. see

Another Example Of An Environmental Tradeoff - Reduced CO2 Emissions And Lower Fuel Cost Versus Personal Safety

Congress should require that the fuel standard not be achieved by simply reducing the size and/or weight of cars, but through technology improvements.

I have generally supported most EPA actions which have been designed to support environmental improvement. These regulations have resulted in much cleaner water and air quality over the past several decades; e.g. see

National Research Council, 2003: Managing carbon monoxide pollution in meteorological and topographical problem areas. The National Academies Press, Washington, DC, 196 pp.

However, the EPA Endangerment Findings for CO2 as a climate forcing falls far outside of the boundary of the type of regulations that this agency should be seeking.

The EPA on April 17, 2009 released this finding in “Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act”.  

This report is a clearly biased presentation of the science which continues to use the same reports (IPCC and CCSP) to promote a particular political viewpoint on climate (and energy) policy).

The text includes the statements

“The Administrator signed a proposal with two distinct findings regarding greenhouse gases under section 202(a) of the Clean Air Act:

Action

“The Administrator is proposing to find that the current and projected concentrations of the mix of six key greenhouse gases—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)—in the atmosphere threaten the public health and welfare of current and future generations. This is referred to as the endangerment finding.

The Administrator is further proposing to find that the combined emissions of CO2, CH4, N2O, and HFCs from new motor vehicles and motor vehicle engines contribute to the atmospheric concentrations of these key greenhouse gases and hence to the threat of climate change. This is referred to as the cause or contribute finding.”

As Climate Science has shown in the past; e.g. see

New Plans To Regulate CO2 As A Pollutant

Comments On The Plan To Declare Carbon Dioxide as a Dangerous Pollutant

A Carbon Tax For Animal Emissions - More Unintended Consequences Of Carbon Policy In The Guise Of Climate Policy

Will Climate Effects Trump Health Effects In Air Quality Regulations?

Supreme Court Rules That The EPA Can Regulate CO2 Emissions

Science Issues Related To The Lawsuit To The Supreme Court As To Whether CO2 is a Pollutant

the “cause” for their endangerment finding can cover any human caused climate forcing. For just one example, the paragraph above could be rewritten as

The Administrator is further proposing to find that the combined emissions of CO2 and CH4 from agriculture contribute to the atmospheric concentrations of these key greenhouse gases and hence to the threat of climate change. This is referred to as the cause or contribute finding.”

The EPA, by expanding its authority to be able to regulate for climate, will have enormous power to regulate all aspects of society. The seriousness of this grasp for power, using “science” as the tool, needs to be widely communicated and debated.

Further information is given at “Overview of EPA’s Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act”, where it includes the information

 ”After a thorough examination of the scientific evidence on the causes and impacts of current and future climate change, as well as other effects of greenhouse gases, the Administrator concludes that the science compellingly supports a positive endangerment finding for both public health and welfare. In her decision, the Administrator relied heavily upon the major findings and conclusions from recent assessments of the U.S. Climate Change Science Program and the Intergovernmental Panel on Climate Change.”

“The Administrator is proposing this endangerment finding after considering both observed and projected future effects of climate change, key uncertainties, and the full range of risks and impacts to public health and welfare occurring within the United States. The scientific evidence concerning risks and impacts occurring outside the United States, including risks and impacts that can affect people in the United States, provides further support for this proposed endangerment finding.”

What these statements tell us is that their finding includes results from multi-decadal climate predictions, which have never shown regional predictive skill, including any ability to predict past major weather events such as droughts!

Nevertheless, they make claims with respect to the climate risks as if these are certain, despite the absence of skill in predicting them for the 20th century. They claim that

 ”The effects of climate change observed to date and projected to occur in the future include, but are not limited to, more frequent and intense heat waves, more severe wildfires, degraded air quality, more heavy downpours and flooding, increased drought, greater sea level rise, more intense storms, harm to water resources, harm to agriculture, and harm to wildlife and ecosystems. The Administrator considers these impacts to be effects on public health and welfare within the meaning of the Clean Air Act.”

In the document “Frequently Asked Questions on the Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases”, they have the Q&A

 ”On what science was the proposed Endangerment Finding based?

“The Administrator relied heavily on existing, peer-reviewed scientific literature. In particular, she relied on reports and conclusions from the U.S. Climate Change Science Program, the National Research Council, and the Intergovernmental Panel on Climate Change because they represent the current state of knowledge on climate change science, vulnerabilities, and impacts. These studies are authored by leading scientific experts and underwent multiple layers of peer review, including, in many cases, review and acceptance by government agencies.”

As documented in

Pielke Sr., Roger A., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy.Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp.

Pielke Sr., Roger A., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“. 88 pp including appendices.

Protecting The IPCC Turf - There Are No Independent Climate Assessments Of The IPCC WG1 Report Funded And Sanctioned By The NSF, NASA Or The NRC.

the conflict of interest (with most of the same individuals leading the reports) is easy to see; i.e. the Federal (non-EPA) expert reviewers for the EPA Endangerment findings (see “Technical Support Document for the Proposed Findings”) are

Virginia Burkett, USGS; Phil DeCola; NASA (on detail to OSTP); William Emanuel, NASA; Anne Grambsch, EPA; Jerry Hatfield, USDA; Anthony Janetos; DOE Pacific Northwest National Laboratory; Linda Joyce, USDA Forest Service; Thomas Karl, NOAA; Michael McGeehin, CDC; Gavin Schmidt, NASA; Susan Solomon, NOAA; Thomas Wilbanks, DOE Oak Ridge National Laboratory.

In conclusion, the EPA Endangerment findings is the culmination of a several year effort for a small group of climate scientists and others to use their positions as lead authors on the IPCC, CCSP and NRC reports to promote a political agenda.

Now that their efforts have reached the federal policy decision level, Climate Science urges that there be an independent commission of climate scientists who can evaluate the assement process that led to the EPA findings as well as the climate science upon which it is constructed.

There is a new paper (which one of authors, Professor Darin Toohey, effectively weblogged on last week; see). The article is

Ross, M., D. Toohey, M. Peinemann, and P. Ross, 2009: Limits on the Space Launch Market Related to Stratospheric Ozone Depletion Astropolitics, 7, 50-82, doi:10.1080/14777620902768867.

and which directly relates to the issue of geoengineering as discussed, for example, in a recent interview by John Holdren who is President Obama’s science advisor (see), and weblogged on by Professor Toohey.

The abstract of the paper reads

 ”Solid rocket motors (SRMs) and liquid rocket engines (LREs) deplete the global ozone layer in various capacities. We estimate global ozone depletion from rockets as a function of payload launch rate and relative mix of SRM and LRE rocket emissions. Currently, global rocket launches deplete the ozone layer ∼0.03%, an insignificant fraction of the depletion caused by other ozone depletion substances (ODSs). As the space industry grows and ODSs fade from the stratosphere, ozone depletion from rockets could become significant. This raises the possibility of regulation of space launch systems in the name of ozone protection. Large uncertainties in our understanding of ozone loss caused by rocket engines leave open the possibility that launch systems might be limited to as little as several tens of kilotons per year, comparable to the launch requirements of proposed space systems such as spaceplanes, space solar power, and space reflectors to mitigate climate change. The potential for limitations on launch systems due to idiosyncratic regulation to protect the ozone layer present a risk to space industrial development. The risk is particularly acute with regard to the economic rationale to develop low-cost, high flight rate launch systems.”

with its press releases at:  http://atoc.colorado.edu/~toohey/PUMA.html.

Clearly, as reported on Climate Science, any attempt for a solution  to an environmental concern which is considered too narrowly (e.g. see also with respect to biofuels), can result in serious unanticipated consequences. For additional discussion on Climate Science with respect to geoengineering; see

Comments On The Physics Today Article “Will Desperate Climates Call for Desperate Geoengineering Measures?” by Barbara Goss Levi.

On Friday, March 6 2009, Professor Gregory R. Carmichael of the Department of Chemical & Biochemical Engineering at The University of Iowa presented one the most insightful talks I have ever attended. The title of this talk was “What Goes Around Comes Around”.

There were several very important findings that were presented, which include

1. “We know that regional control strategies are needed to meet local air quality targets”. [from slide 4]

This perspective recognizes that it is regional weather and climate that needs to be focused on in order to improve air quality.

2. with respect to air pollution ” Large and small sources combine resulting in a global reach of pollution…..The majority of impacts are domestic, BUT Intercontinental transport of PM2.5 is associated with 100,000 premature mortalities world-wide of adults 30 years and older. Intercontinental transport of PM2.5 into USA results in ~1200 excess deaths! (tightening the U.S. 8-hour O3 standard from 84ppbv to 75ppbv, is annually projected to prevent 1,300 to 3,500 premature deaths in the United States at a cost of $7.6-8.8 billion USD each year [EPA, NAAQS RIA, 2008]) [from slide 11]“.

The global reach of pollution that Professor Carmicheal finds is in agreement with one of the findings in the 2005 NRC report that

“Regional variations in radiative forcing may have important regional and global climatic implications that are not resolved by the concept of global mean radiative forcing. Tropospheric aerosols and landscape changes have particularly heterogeneous forcings.”

3. “As air quality standards become more stringent the importance of distant sources increases. [The] contribution of Asia pollution to  [the] USA is growing — we estimate that it is nullifying 15% of our emission reduction efforts !!”

This conclusion also supports the 2005 NRC conclusion that is presented under #2.

4. “Full application of advanced emission control technologies can reduce health impacts in China by 43% in 2030; optimized saves 80% of costs”.

Professor Carmichael showed that this benefit also results in an 8% decrease in greenhouse gas emissions even with a focus on air quality benefits 

This conclusion shows that by focusing on improving air quality can also result in a reduction of greenhouse gases. However, as shown in #5, delaying the reduction of certain types of aerosols (e.g. sulphates) in order to retain a global average radiative cooling will result in early deaths than otherwise would not occur.

5. “350,000 excess deaths per year in India and China due to outdoor exposure risk for each 20mg/m3 (of fine aerosols of less than 2,5 microns). In addition to a WHO estimate of 381,000 and 407,000 (deaths) for China and India, respectively, from indoor air pollution caused by solid fuel use.”

This conclusion documents the immediate benefit of reducing fine particles in the atmosphere regardless of the impact on the emissions of greenhouse gases.

The only part of his talk which I disagreed with was his conclusion to decrease black carbon emissions faster than sulfates [from slide 19]. As Professor Carmichael reports in #4, excess deaths can be reduced if fewer fine particles are emitted into the atmosphere that is breathed. It does not matter if these are sulphates or black carbon (or other aerosols).  A delay in reducing sulphates simply to retain their globally cooling effect would condemn many people to an early death.

Thanks to Mike Smith for alerting us to this news article

 New Jersey, Pennsylvania farmers don’t like the smell of a federal ‘cow tax’ by Bill Wichert on Sunday, December 28, 2008 in The Express-Times

The article includes the text

“The rear end of a cow could become the next source of financial hardship for farmers.”

“Facing lower milk prices and higher operational costs, dairy farmers in New Jersey and Pennsylvania say they couldn’t afford the so-called cow tax, a suggestion made by federal officials to charge permit fees for livestock as a way of regulating greenhouse gas emissions.”

“The U.S. Environmental Protection Agency raised the concept in a recent report on possible greenhouse gas regulations under the Clean Air Act. Those regulations also could be extended to small businesses, schools, hospitals and churches.”

“In its comments on the EPA proposal, the U.S. Department of Agriculture said the regulations might force permitting requirements on dairy farms with more than 25 cows, beef cattle operations with more than 50 cattle, swine facilities with more than 200 hogs and farms with 500 or more acres of corn.”

“The permit costs would mean $175 per dairy cow, $87.50 a head for beef cattle and $20 per hog, according to Liz Thompson, a research associate with the New Jersey Farm Bureau. A herd of 75 dairy cows would carry a price tag of about $13,000.”

This is the type of pandora’s box that Climate Science has weblogged on in the past; e.g. see

Has The IPCC Produced A Hydra?

The clear answer is that a wide range of consequences, with serious environmental, economic and social effects, are going to result as a result of the inappropriately narrow IPCC focus on carbon as the currency for a wide range of climate effects.

The weblogs ICECAP and Watts Up With That have alerted us to the plan to list carbon dioxide as a pollutant by the EPA where they report on an article titled “Obama to Declare Carbon Dioxide Dangerous Pollutant” by Jim Efstathiou Jr. of Bloomberg.

Climate Science has weblogged on this subject in the past; see

Will Climate Effects Trump Health Effects In Air Quality Regulations?

Supreme Court Rules That The EPA Can Regulate CO2 Emissions

Science Issues Related To The Lawsuit To The Supreme Court As To Whether CO2 is a Pollutant

What the listing of carbon dioxide as a pollutant would do is to implicitly declare that any human activity that affects climate could be considered a pollutant. This would logically mean, for instance,  that the EPA could regulate land use since, as extensively documented in the peer reviewed literature (e.g. see), landscape change is a human climate forcing.

This plan to regulate CO2 as a pollutant (since it is a human climate forcing) would give them the legal rationale to permit the implementation of additional federal regulations for other human climate forcings including the zoning of how land is developed.  Everyone should realize the implications and significance of this potential expansion of federal authority.  There may be societal benefits to such broad climate regulation authority, however, this issue should be more effectively discussed and debated than it has been up to the present.

UPDATE: It has been pointed out to me that the EPA does not have the “legal” rationale (i.e. precedent or law) to permit the  implementation of additional federal regulations for other human climate forcings. Hence, I have removed”legal” (by the strike out).

The Website Science Debate 2008 has the following information on the positions of Senators Obama and McCain on climate. The question and their responses follow:

Climate Change.  The Earth’s climate is changing and there is concern about the potentially adverse effects of these changes on life on the planet. What is your position on the following measures that have been proposed to address global climate change—a cap-and-trade system, a carbon tax, increased fuel-economy standards, or research?  Are there other policies you would support?

Senator Barack Obama’s response:

“There can no longer be any doubt that human activities are influencing the global climate and we must react quickly and effectively. First, the U.S. must get off the sidelines and take long-overdue action here at home to reduce our own greenhouse gas emissions. We must also take a leadership role in designing technologies that allow us to enjoy a growing, prosperous economy while reducing greenhouse gas emissions by 80 percent below 1990 levels by 2050. With the right incentives, I’m convinced that American ingenuity can do this, and in the process make American businesses more productive, create jobs, and make America’s buildings and vehicles safer and more attractive. This is a global problem. U.S. leadership is essential but solutions will require contributions from all parts of the world—particularly the rest of the world’s major emitters: China, Europe, and India.

Specifically, I will implement a market-based cap-and-trade system to reduce carbon emissions by the amount scientists say is necessary: 80 percent below 1990 levels by 2050. I will start reducing emissions immediately by establishing strong annual reduction targets with an intermediate goal of reducing emissions to 1990 levels by 2020. A cap- and-trade program draws on the power of the marketplace to reduce emissions in a cost- effective and flexible way. I will require all pollution credits to be auctioned.

I will restore U.S. leadership in strategies for combating climate change and work closely with the international community. We will re-engage with the U.N. Framework Convention on Climate Change, the main international forum dedicated to addressing the climate change problem. In addition I will create a Global Energy Forum—based on the G8+5, which includes all G-8 members plus Brazil, China, India, Mexico and South Africa—comprising the largest energy consuming nations from both the developed and developing world. This forum would focus exclusively on global energy and environmental issues. I will also create a Technology Transfer Program dedicated to exporting climate-friendly technologies, including green buildings, clean coal and advanced automobiles, to developing countries to help them combat climate change. ”

Senator John McCain’s response:

“We know that greenhouse gas emissions, by retaining heat within the atmosphere, threaten disastrous changes in the climate. The same fossil-fuels that power our economic engine also produced greenhouse gases that retain heat and thus threaten to alter the global climate. No challenge of energy is to be taken lightly, and least of all, the need to avoid the consequences of global warming. The facts of global warming demand our urgent attention, especially in Washington. Good stewardship, prudence, and simple commonsense demand that we act to meet the challenge, and act quickly.

To dramatically reduce carbon emissions, I will institute a new cap-and-trade system that over time will change the dynamic of our energy economy. By the year 2012, we will seek a return to 2005 levels of emissions, by 2020, a return to 1990 levels, and so on until we have achieved at least a reduction of sixty percent below 1990 levels by the year 2050. In doing this, we will transition into a low carbon energy future while promoting the technological innovations that keep us on a course of economic growth. The purpose of this approach is to give American businesses new incentives and rewards to seek cheaper emission reductions, instead of just new taxes to pay and new regulations to follow. This approach gives people time to adapt, instead of causing a sudden jolt to electricity bills and potential shutdowns of tradition coal-fired plants.

I have long supported CAFE standards - the mileage requirements that automobile manufacturers’ cars must meet. Some carmakers ignore these standards, pay a small financial penalty, and add it to the price of their cars. But I believe that the penalties for not following these standards must be effective enough to compel all carmakers to promote the development of fuel-efficient vehicles. I will strengthen the penalties for violating CAFE standards, and make certain they are effectively enforced.

To bolster research efforts, government must do more by opening new paths of invention and ingenuity. A McCain administration would establish a permanent research and development tax credit equal to ten percent of wages spent on R&D, to open the door to a new generation of environmental entrepreneurs. I am also committed to investing two billion dollars every year for the next 15 years on clean coal technologies, to unlock the potential of America’s oldest and most abundant resource. And we will issue a Clean Car Challenge to automakers, in the form of a tax credit to the American people, for every automaker who can sell a zero-emission vehicle. We will commit up to a 5,000 dollar tax credit to each and every customer who buys that car. In the quest for alternatives to oil, our government has thrown around enough money subsidizing special interests and excusing failure. From now on, we will encourage heroic efforts in engineering, and we will reward the greatest success.

I further propose we inspire the ingenuity and resolve of the American people by offering a $300 million prize for the development of a battery package that has the size, capacity, cost and power to leapfrog the commercially available plug-in hybrids or electric cars. This is one dollar for every man, woman and child in the U.S. — a small price to pay for helping to break the back of our oil dependency – and curb the dangerous effects of global climate change.

I will continue to support the US Global Change Research Program and ensure that the program’s activities support the Nation’s needs for climate related information to help it prepare for the future.”

Three possible descriptions of climate have been discussed on Climate Science; see

Three Climate Change Hypotheses - Only One Of Which Can Be True.

These characterizations of climate are

•  The human influence is minimal and natural variations dominate climate variations on all time scale;
• While natural variations are important, the human influence is significant and involves a diverse range of first-order climate forcings (including, but not limited to the human input of CO2);
• The human influence is dominated by the emissions into the atmosphere of greenhouse gases, particularly carbon dioxide.

Both candidates clearly subscribe to the third hypothesis.

Climate Science’s perspective is that the second hypotheses is correct, which has support from the

National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.

There is an article on geoengineering of the climate system;

Levi, B. G., 2008: Will desperate climates call for desperate geoengineering measures? Earth scientists ponder the wisdom of large-scale efforts to counter global warming. Physics Today, 61:8, 26-28.

Excerpts of the article read

“Concerned that Earth’s climate will change to an unacceptable degree or at an unacceptable rate before economies can shift significantly away from carbon-based energy sources, some scientists have begun casting their eyes in a previously shunned direction: geoengineering, or intentional and large-scale intervention to prevent or slow changes in the climate system.

Geoengineering sometimes refers strictly to techniques for increasing Earth’s albedo, or reflectivity, to lower its temperature and compensate for greenhouse warming. More broadly, the term can include efforts to accelerate some of the natural processes for removal of CO₂ from the atmosphere. Many such ideas have been around for decades. In the past few years, however, the debate over their potential deployment has intensified.”

The figure below, reproduced from their paper (unfortunately, the image is poor), presents different geoengineering approaches and their relative costs and risks.

 (Figure originally from Kurt House, Harvard University.)

Each of these porposals for geoengineering of climate, however, are fraught with very significant risk!

As discussed in an early Climate Science weblog What is the Importance to Climate of Heterogeneous Spatial Trends in Tropospheric Temperatures?

“…..regional diabatic heating due to human activities represents a major, but under-recognized climate forcing, on long-term global weather patterns. Indeed, this heterogeneous climate forcing may be more important on the weather that we experience than changes in weather patterns associated with the more homogeneous spatial radiative forcing of the well-mixed greenhouse gases…”

The proposed options of geoengineering of climate illustrated in the figure would result in new human heterogeneous climate forcing. Since we do not even yet know the consequences of the existing inadvertent non-homogeneous human climate forcings such as land use/land cover change and aerosols (i.e. see), the introduction of deliberate heterogeneous human climate forcings is dangerous and irresponsible.

The claim in the Levi Physics Today article that geoengineering “intervention” [can] prevent or slow changes in the climate system is completely wrong. Geoengineering  would cause changes in the climate system!  The Levi focus almost exclusively on the role of the addition of carbon dioxide into the atmosphere is blind to the importance of altering the spatial pattern of climate forcing as a result of geoengineering.