A Free-Market Energy Blog

U.S. EPA is Ill-Equipped to Fight Global Warming

By Chip Knappenberger -- April 28, 2009

Now that the U. S. Environmental Protection Agency (EPA) has announced intent to find that greenhouse gas emissions (primarily carbon dioxide) from human activities lead to the “endangerment of public health and welfare,” the question arises: What could EPA theoretically do about it? (I’ll leave the politics to others.) In other words, can a U.S.-side agency conceptually protect U.S. citizens from the endangerment of their health and welfare from the global issue of  global warming?

It turns out that they cannot do much of anything. EPA is simply saber-rattling to get Congress’s attention. If the agency was forced to actually draw their weapon in battle, they would be holding a rubber sword against a massive and growing global force. The bottom line: the EPA is brandishing only about 0.0033ºC/yr-worth of global temperature influence—and that is only if it managed to shut down all greenhouse gas emissions from U.S. economic activity and keep it that way. All the while, the warming pressure from the rest of the world steadily grows, shrinking the EPA’s already too-small-to-matter arsenal.

This can be understood by simplifying the issue down to the Xs and Os—carbon dioxide emissions and global temperatures.

I’ll cast carbon dioxide emissions in terms of the global temperature change they produce based on a few reasonable (although short of perfect) assumptions and then explore via the back of the envelope the potential impact of any EPA regulations.

Assumption 1: Based on both observations and climate model projections, it takes an increase in the atmospheric concentration of carbon dioxide (CO2) of about 115 parts per million (ppm) to raise the global average temperature about 1ºC. Certainly, there is a lot of quibble room here (like the CO2 effect is logarithmic rather than linear), but this number is not that far off for the current conditions.

Assumption 2:Based upon observations, it takes about 15,500 million metric tons (mmt) of carbon dioxide emissions to raise the atmospheric CO2 concentration 1 ppm. This is based on the observations that show that about half of the human CO2 emissions remain in the atmosphere and that this percentage has stayed relatively constant since good atmospheric concentration measurements began in the late 1950s. The 15,500 number comes from dividing the total global annual CO2 emissions each year by the annual CO2 increase (data available from CDIAC if you want to see for yourself). Again you could nit-pick this (like whether or not global CO2 sinks will continue to grow), but this will work for the time being.

These two assumptions lead to the generality that it takes about 15,500 mmtCO2/ppm times 115 ppm/ºC which equals 1,782,500 mmt of CO2 emissions to produce a global temperature rise of 1ºC.

This is a handy number to have. Every time you see someone touting some action that will lower CO2 emissions (and thus “save the planet” from global warming), you can take their emissions savings (in mmtCO2), divide it by the number above (1,782,500 mmtCO2/ºC) and see just how much of the planet they are saving.

Here I’ll use it to look at what kind of temperature rise is being produced by U.S. emissions and what kind of temperature rise is being produced by the rest of the world (over which the U.S. EPA has no regulatory authority).

In 2006, U.S. CO2 emissions were 5,903 mmtCO2, and the emissions from the rest of the world totaled 23,292 mmtCO2. So that means, roughly speaking, that with its 20% (and falling) world share, U.S. emissions in 2006 caused about 0.0033ºC (5903÷1,782,500) of global warming while emissions from the rest of the world caused about 0.0131ºC (23,292÷1,782,500). Now, the astute among you may point out that the global temperature didn’t increase by 0.0164ºC from 2005 to 2006—but realize that my analysis is aimed at a general characterization of the influence of CO2 emissions from human activities, and does not include other influences on the earth’s temperature, which, as we have seen over the past decade or so are quite large as they have acted to offset all the warming from CO2 emissions during that time.

Figure 1 shows the results from not just 2006 but for the past 10 years (more specifically 1997-2006 since this is the most recent data available from the Energy Information Administration) from the U.S. and from the rest of the world.


Figure 1. Influence on global temperature from U.S. CO2 emissions (blue) and emissions from the rest of the world (maroon). The overall height of each bar represents the total influence from CO2 emissions on global temperatures (emissions data from the EIA).

Notice a few things. The amount of global warming each year that the U.S. is responsible for averages about 0.0033ºC per year—an amount that has changed little during this 10-yr period. And, at the same time, the amount of global warming contributed by emissions from the rest of the world has increased from about 0.010ºC/yr in the late 1990s to about 0.013ºC/yr during the past couple of years. This means that the percentage of the total warming that the U.S. is responsible for has been declining—which of course, means that the EPA’s ability to mitigate global warming by reigning in U.S. CO2 emissions is waning. In other words, as total emissions from the rest of the world grow at a pace that far exceeds that of the U.S. emissions, the EPA’s ability to protect Americans from the endangerment of their health and welfare diminishes.

Let’s look at it another way. This time, supposing that the EPA had made its endangerment finding in 1997 and issued regulations that (miraculously) eliminated all U.S. CO2 emissions within the proceeding 10 years (i.e. from 1997 to 2006), the chart in Figure 1 would look like this (Figure 2).


Figure 2. Influence on global temperature from U.S. CO2 emissions (blue) and emissions from the rest of the world (maroon) assuming that the EPA instituted regulations in 1997 that reduced the U.S. CO2 emissions to zero by 2006. The overall height of each bar represents the total influence from CO2 emissions on global temperatures.

The net result of this monumental achievement would have been that the EPA would have managed to hold the rate of global warming (total height of the bars) relatively steady during this period—this is not the actual global temperature, mind you, but just how fast it was warming from one year to the next. And most significantly, in doing so, it would have used up all of its chits! Having eliminated all U.S. emissions (whose reductions were being used to offset emissions increases from elsewhere around the world), total global emissions will once again continue their rise and so too will the rate of global temperature increase. And the EPA will be played out.

The only lasting feather in EPA’s cap would be that it managed to eliminate 0.0033ºC of warming each year if it were successful at completely eliminating all U.S. CO2 emissions, forever. It would be mighty interesting to see a quantification of the endangerment that it avoided by doing so. My bet is that it would be embarrassingly small. And the effort to do so would be embarrassingly large.

It is hard to imagine that the EPA couldn’t serve us in far better ways.


  1. Ed Reid  


    GISS already presents temperatures and anomalies to at least 2 insignificant figures. Your analysis above increases the presentation to at least 4 insignificant figures. You have essentially caused GISS’ insignificance to pale into insignificance. That is quite an accomplishment!

    Based on the NCDC evaluation criteria, the measurement stations used to collect the data which are then massaged by GISS are prone to average errors greater than 2 degrees C, so I am not convinced that the digit to the left of the decimal place in the GISS presentations is significant either.

    I conclude from this that there may be a significant possibility that the issue of AGW might be significant if the reported temperature anomalies are significant; but, that there is a significant chance that the significance of AGW is not really all that significant. Whew!


  2. Andrew  

    AGW policy as farce. Nice work Chip! I’m sure more complicated calculations wouldn’t change the results too much, I’ve seen similar but more complicated analyses which essentially also conclude that no unilateral policy is going to have any effect.


  3. cknappenberger  

    Thanks, Andrew.

    I’ve got a few of those “more complicated” calculations in the works as well…so stay tuned!



  4. C3H Editor  

    I thought the generally accepted influence of doubling CO2 was a temperature increase of 1.2 C.

    And, if pre-industrial PPM was 280 and a doubling meant 560 in future……

    If the above were true, and putting aside the logarithmic issue, would not the average PPM impact on temps be 0.0043c — (1.2c/(560ppm-280ppm))?

    So, to raise the temperature by one degree it would take 233 ppm, not 115 ppm (on average, not logarithmic).

    Where I have gone wrong on computations and/or facts to come up with a different number than you present? (I like your end result better than mine, but yours is the first time I seen someone write that 115 ppm = 1c.


    C3H Editor


  5. cknappenberger  

    C3H Editor,

    I sort of averaged between observations and some model results to get that number. I am not suggesting that it is set in stone, but I think it is reasonable.

    Just looking at the observed end of things, the atmospheric CO2 concentration has increased from about 280 to 380ppm and the global average temperature has incrased about 0.8C. So dividing a 100ppm by a 0.8C increase gets you 125ppm/C–not far from my number.

    Your 233ppm/C is based on theory (assuming no feedback) while mine is a bit more empirical (although, to get my 115 number I did incorporate some climate model (theory) results).



  6. C3H Editor  

    Thanks, Chip. That explanation helps explain why my calculations produced a different result.


  7. Sean  

    I think the rubber sword is a poor anology. The EPA ruling is the initial challenge in a game of chicken the executive branch is doing with the legislative branch — reduce emissions through legislative action or the executive branch will do something stupid. If the EPA wields its weapon because the legislative branch does not do the “right thing”, the weapon will do serious damage, just not to the problem at hand.


  8. cknappenberger  


    The rubber sword is the EPA’s weapon to attack global warming (i.e. the climate aspect of the issue). As you point out, it wields a much mightier sword with which to wreak havoc on the non-climate aspects.



  9. Sean  

    I think a better analogy is using a shotgun to rid your home of ants. If you point it at the wall where the ants are coming from you’ll kill a few, scatter most and do much more damge to your home than the ants ever would.


  10. C3H Editor  


    Thought some more about your response and have to “quibble.” You’re attributing +0.8 C exclusively to CO2. Your close associates suggest that socioeconomic, land-use and UHI effects are a big part of that +0.8. Taking those factors into account would reasonably lower the +0.8 to +0.4 instead. If these other factors are taken into account, then that 115 ppm that causes a 1C change becomes 225 ppm to make the same 1C change, much closer to theoretical calculation.

    Since you have a big megaphone on this blog (which is good), you might consider the very influential impacts of your assumptions when discussing important points. If you believe that there are other factors that have “caused” the 0.8 increase, then start your calculation with an assumed CO2 causal increase that is lower. Of course, if you believe 100% of the +0.8 C change was due to CO2, then keep on Hummer-ing (trucking)!

    C3H Editor


  11. Andrew  

    C3H Editor-There is a thing called arguing from your opponent’s assumptions-or being generous-which adds strongly to the force of the argument-it is true whether Chip’s associate’s claims are true or not (and many reject that possibility outright). In other words ~regardless~ of what one believes about climate, even the strong view of advocates of catastrophic AGW, the EPA is totally ineffectual-it doesn’t come close to doing what it is supposed to.


  12. Andrew  

    Chip, I see that you have done a more in depth analysis over at WCR. There is still something missing, however, which would have been easy to calculate. How much money you’d have to spend in offsets to prevent a whole degree of temperature rise. Based on the values given, it works out to about $25,000,000,000,000 per degree C (a simple linear regression of the coordinates (3.11*10^-12, 84) and (1.36*10^-11, 364) extrapolates out to about this figure (actually higher)). Now I think that is way too much, don’t you? 🙂


  13. Andrew  

    Although I should note it is actually a bargain compared to Kyoto:


  14. Deamiter  

    So… the entire argument is that because the US generates only part of the pollution, the US should do nothing domestically because the country can’t solve the problem on its own?

    I get the feeling this could only make sense to somebody who utterly denies any AGW. If you step back for a moment and assume (as this entire argument does) that this warming is a problem, saying that we should do nothing just because if we act alone we will accomplish little is just silly!

    No, the EPA is probably not the best agency to regulate CO2 emissions in the USA, but the article doesn’t even make THAT point as it assumes that ALL emissions are eliminated, a result that would not depend on the source of the regulation.


  15. alena  

    US contribution of CO2 emissions in 2006 looks to me like 25%, not 20%, given your numbers in the article. Unless you are eliminating the emissions from liberals.


  16. SS  

    These are great examples of how insignificant we are in the whole scheme of climate change. One more point – temperatures are going DOWN! The whole AGW argument is a red herring.


  17. cknappenberger  

    C3H Editor,

    Granted it is probable that all the warming in the past 150 years is not from CO2 increases, but it is also probable that all the warming from CO2 increases to date has not yet been realized. Lacking a good quantification of these, I am happy to call it a wash.

    I develop this concept a bit further over at World Climate Report in a just-posted article What You Can(‘t) Do About Global Warming .

    Check it out.



  18. cknappenberger  


    But I am only a climatologist, not an economist! :^)



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