October 8, 2009

The Ups and Downs of Methane

One of the indisputable facts in the field of global climate change is that the atmospheric build-up of methane (CH4) has been, over the past few decades, occurring much more slowly than all predictions as to its behavior (Figure 1). Since methane is a particularly potent greenhouse gas (thought to have about 25 times the warming power of CO2), emissions scenarios which fail to track methane will struggle to well-replicate the total climate forcing, likely erring on the high side—and feeding too much forcing into climate models leads to too much global warming coming out of them.

Figure 1. Atmospheric methane concentrations, 1985-2008, with the IPCC methane projections overlaid (adapted from: Dlugokencky et al., 2009)


June 16, 2009

Does EPA Have the Wrong Gas?

Over at MasterResource.org is an article looking at EPA’s Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Sections 202(a) of the Clean Air Act, and wonders whether or not the EPA has set its sight on the correct gas. The EPA’s focus seems to be on carbon dioxide, but a very strong case can be made that the net effect of increasing atmospheric carbon dioxide concentrations may not be so bad (in fact, it may be quite good). So instead of risking the possibility that if they consider the climate impacts of CO2 alone they very well may not be able to build a case for an “endangerment to public health or welfare,” the EPA has lumped CO2 together with five other greenhouse gases thus watering down the positive aspects of CO2 with the potential negative ones from the other gases.

The MasterResource piece argues that to make a fair assessment of its effect on climate, CO2 should be unlumped and considered on its own.

June 10, 2009

Sulfates and Global Warming

Usually when we think of global warming, we are led to believe that it is caused primarily by increasing greenhouse gases. After all, that is what all the fuss is about in Washington DC these days. But is that entirely true?

After all there are lots of other things going on all the while. For instance, to what degree has the global temperature record in recent decades been influenced by the variability in aerosol emissions?

This question has been the subject of a series of articles in recent years by Martin Wild and colleagues which look at the impacts of (primarily sulfate) aerosols on the earth’s climate. They typically conclude that sulfate aerosols play a larger role in multi-decadal climate fluctuations than the climate models generally give them credit for. And that models’ inability to properly handle the climate aspects of aerosols “may hamper the predictive skills of these models to project near future climate evolution.”


May 20, 2009

No Climate Impact from New National Fuel Efficiency Standards

Recently we worked through the steps required to derive a handy-dandy way to convert carbon dioxide emissions savings to global temperature savings and suggested a few ways in which to apply it. Our primary objective was to put into everyone’s hands a quick-and-easy way for the common man to do what most climate-change-through-emissions-reductions advocates won’t do themselves (or, rather, don’t want you to know the result)—that is, put a climate face on their proposed actions.

The reason that they don’t do this themselves, is that despite all the global warming bluster, their proposed actions have virtually no direct impact on the course of future climate change.

Such is the case with the recently proposed national automobile fuel efficiency standards.


April 16, 2009

Who is Behind the Current Emissions Trends?

There is a lot being made in some circles about how we are currently on an emissions pathway that exceeds even the worst case projections used by the IPCC. This is used to support pleadings that we take immediate and significant action to reduce our profligate usage of fossil fuels, or we risk making the planet inhospitable to human societies.

The problem is that it is unclear who “we” are. Since most of these pleadings seem to be aimed at the current U.S. Congress to get it to pass legislation to limit the lifestyle of those under its control, it would seem like “we” are Americans.

But it this really a very effective course of action? Are Americans the reason that the current pathway of total global carbon dioxide emissions exceeds the IPCC’s wildest expectations? Or is there a more appropriate target audience?

To help you decide for yourself, we plot below the annual (energy-based) carbon dioxide emissions from various portions of the world for the past 10 years (through 2006, the last data available from the Energy Information Administration).

Figure 1. Annual energy-related carbon dioxide emissions from various portions of the world, 1997-2006 (source: Energy Information Administration)

Notice that one of these things is not like the others. And that thing is…China.

The emissions growth in China over the past 10 years (actually over the past 6-7) is simply astounding. Since 2000, China has increased its CO2 emissions by nearly 50% more than the rest of the world combined. In fact, had China’s CO2 emission changes for the past 10 years paralleled those of the United States (which was responsible for only a few percent of the global emission growth since 2000), the world would be on an emissions pathway that would lie very near the lowest scenario considered by the IPCC.

If other words, “we” (Americans) have little responsibility for “our” (global) emissions growth during the past 5-10 years.

Here is another way to look at it.

China has increased its national emissions since 2000 by an amount equivalent to about half the total annual U.S. emissions. That means, just to offset Chinese emissions growth, each and every one of us (Americans) would have had, on average, to have reduced our CO2 emissions by 50% during the same period. And this would only to be to offset China’s growth! Give China a few more years (although the global recession will slow things down a bit—temporarily) and China’s emissions growth will have exhausted our (Americans) potential to effect any more offsets—in other words, even it we (Americans) in 2000 had eliminated all our CO2 emissions, China, by the end of this decade, would most likely have completely replaced them through growth of its own. In only 10 short years, our (Americans) tremendous sacrifice would be forever erased by China’s growth.

The bottom line is clearly thus:

The loudest the pleas to limit carbon dioxide emissions should be being made in Chinese (rather than English), for without reigning in China’s emissions growth, America’s impact on future global climate change will be minuscule. So the alarmists should quit pestering us (Americans) about our energy usage until they have made some serious inroads with China. Recent trends show that “we” are not the problem.

April 15, 2009

Climate Models: Better Clouds=Less Warming?

While all the attention has been focused on a paper by Warren Washington and colleagues that has just been accepted by the scientific journal Geophysical Research Letters (GRL), whose conclusions can perhaps best be summarized by “Yes, Virginia, there is something you (acting together with 7 billion of your closest friends) can do to lessen climate change,” another paper has been published by GRL that seems to argue that if climate models had a better handle on the true behavior of clouds, that they may project less warming than they do now.

So, perhaps Virginia, if you wait for the scientists to get things right, there may be less that you actually have to do in the first place (which is a good thing, because according to the Washington et al. results, you are way behind already).


April 14, 2009

The Cato Climate Ad, Joe Romm, and Swanson&Tsonis

For another look at how the results of the latest work by Kyle Swanson and Anastasios Tsonis—which show, among other things, that the earth’s climate most likely shifted into a state which could result in a slowed rate of global warming lasting for another decade or so—are impacting the processes (both scientific and political) of climate change, see this piece over at MasterResource.org.

April 8, 2009

Has the climate recently shifted?

“Has the climate recently shifted?” is the title of a just-published paper in Geophysical Research Letters by researchers Kyle Swanson and Anastasios Tsonis from the University of Wisconsin-Milwaukee. Their examination of this topic was undoubtedly prompted by the recent behavior of global temperature which shows that the rate of warming has dramatically slowed during the past 7-12 years.

Updating a methodology that they had previously developed and used to identify several changes in the climate state that occurred during the 20th century, Swanson and Tsonis examined the temperature data from recent years to see if another state change had taken place:

Here, a new and improved means to quantify the coupling between climate modes confirms that another synchronization of these modes, followed by an increase in coupling occurred in 2001/02. This suggests that a break in the global mean temperature trend from the consistent warming over the 1976/77–2001/02 period may have occurred.

In other words, the authors think that they have identified another in a string of break points that signal a change in the general state of the earth’s climate.


March 5, 2009

Feedbacks and Climate Sensitivity

A week or two ago, Andrew Dessler and Steven Sherwood published a “Perspectives” (largely opinion) piece in Science magazine that argued that the water vapor feedback was unassailably strong and positive. This means that the warming from the increase in greenhouse gas concentrations leads to more water vapor in the atmosphere which leads to even more warming (water vapor is a strong greenhouse gas itself). This positive feedback results in roughly twice as much warming as would occur from anthropogenic greenhouse gas increases alone.

Dessler and Sherwood concluded:

There remain many uncertainties in our simulations of the climate, but evidence for the water vapor feedback—and the large future climate warming it implies—is now strong.

This conclusion has drawn a lot of attention within the community of researchers investigating the behavior of water vapor and the role of water feedback in climate change—and most of it has been highly critical.


May 2, 2008

China is #1!

Thousands of websites present the usual view of global warming claiming that greenhouse gases are increasing in atmospheric concentration, this is causing the planet to warm, and if we don’t act immediately, an endless number of calamities are certain to become reality. These sites then make every effort to make you believe that much of the problem can be placed at the feet of President Bush, Vice President Cheney, and just about anyone associated with the gas, oil, and coal companies in the United States. There are mentions here and there of contributions from other countries, but you will constantly be reminded that the United States is the largest emitter of greenhouse gases, that the relatively small population of the USA has an immoral per capita emission level, and that no one on the planet should feel more guilty about global warming than folks who voted for the current administration.

To be fair, there have been news reports recently that China’s total emission of carbon dioxide (CO2) has surpassed the emission from the United States. Along these lines, an important article has appeared in Geophysical Research Letters that shows China is now our global leader in CO2 emission, which is certainly newsworthy, but other results presented in their article may be received as bad news by the global warming alarmists. The research was conducted by three scientists at the University of Maryland, the Oak Ridge National Laboratory, and Austria’s International Institute for Applied Systems Analysis; a portion of the research was funded by the U.S. Department of Energy, Office of Science, Biological and Environmental Research Programs.


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