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Terms of Endangerment: EPA to Cut Global Warming Pollution

David Doniger

Posted April 17, 2009

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At long last, the Environmental Protection Agency today officially recognized that the carbon pollution from our cars and power plants leads to killer heat waves, stronger hurricanes, higher smog levels, and many other direct and indirect threats to human health. 

With this step, the Obama administration has gone a long way to restore respect for both science and law. The era of defying science and the Supreme Court has ended. 

SPECIAL NRDC LIVE CHAT: Join David Doniger for a live online discussion about the EPA's endangerment determination on Monday, April 20, at 1 p.m. Eastern here on NRDC's Switchboard blog. Click here to join the chat.

Administrator Lisa Jackson issued an "endangerment determination" under the Clean Air Act -- a finding that carbon dioxide and other heat-trapping air pollutants "may reasonably be anticipated to endanger public health or welfare" and that motor vehicle emissions of those pollutants "contribute" to that dangerous air pollution.

Jackson's EPA and the Obama White House actually have acted quite quickly, producing the endangerment determination less than 90 days into the new president's term.  But it has been a long wait.  The simple acknowledgment that global warming pollution is dangerous to our health and our environment proved to be too much for the Bush administration.  Eight years of scientific and legal denial -- our "little ice age" in Washington -- are finally over (see my previous post "See No Email").  

Ten years ago, in the Clinton administration, EPA's general counsel ruled that CO2 is an air pollutant just like any other air pollutant, and is subject to regulation under the Clean Air Act -- the nation's most effective environmental law -- if the administrator makes an endangerment determination.  But in 2003 the Bush EPA revoked that legal ruling and announced that the Clean Air Act simply does not apply to global warming pollution from motor vehicles.  The next year, EPA took the same position on global warming pollution from power plants. 

NRDC played a leading role in a grand coalition of states and environmental organizations that challenged the EPA rulings.  It took a while, but in 2007 the Supreme Court issued a landmark ruling, Massachusetts v. EPA, flatly rejecting the Bush administration's position.  The Court ruled that CO2 and other greenhouse gases from motor vehicles are air pollutants.  The Court further held that EPA must determine, based on scientific considerations alone, whether those emissions are dangerous to health or welfare, and if so, issue standards to cut their emissions from new cars with available technology. 

Today EPA has issued a bullet-proof scientific review, based on reports from the Nobel prize-winning Intergovernmental Panel on Climate Change, the National Academy of Sciences, and a host of other studies.  The EPA review catalogues the full range of human health and environmental harms attributable to global warming pollution.

The endangerment determination issued today has important consequences.  It requires EPA to follow up with standards under the Clean Air Act to curb emissions of carbon dioxide and other heat-trapping pollutants from new cars.  While EPA has not said exactly what it will do and when, there are strong indications the administration is working on a plan to issue national standards for vehicles that equal or exceed those set by California ("Smile and Waive" ) -- that would be a great achievement.

EPA also will soon have to address whether power plants' CO2 emissions "contribute" in the same way to dangerous global warming pollution.  Since power plants are responsible for twice as much heat-trapping emissions as cars, the answer is obvious. 

To be sure, today's announcement is a proposal, and everyone - including the dwindling ranks of climate deniers - will have a chance to comment on EPA's scientific conclusions.  The final determination will likely be issued in conjunction with the final national vehicle standards next year.  But given the state of the science, there's not the slightest doubt about the outcome. 

The Chamber of Commerce and others will claim that using the Clean Air Act against global warming pollution will lead to economic disaster.  But those are just scare tactics (see "The Phony 'Train Wreck'"). 

We have the technology to cut global warming pollution from our cars, power plants, and other sources, mainly by making and using energy more efficiently, and by adopting renewable and cleaner energy sources.  The energy technology revolution will help our economy recover, create millions of green jobs, save consumers billions of dollars, and cut our dangerous dependence on foreign oil.

NRDC salutes President Obama and Administrator Jackson for their actions to tackle global warming.  We will work with them to carry out the existing Clean Air Act, and we'll work with them and with leaders in Congress, including Henry Waxman and Ed Markey, to enact comprehensive new climate legislation ("'First Read'"). 

The climate is too big to be allowed to fail.

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SheldonApr 17 2009 12:59 PM

Mr. Doniger,

What is your preferred approach to addressing global climate change? Regulation by the EPA, federal cap and trade legislation, or some other mechanism?

Sig-Linda JacobsonApr 17 2009 10:25 PM


I heard you on NPR this evening. It's been a long time. Would love to hear from you - e-mail


Devin McDougallApr 17 2009 10:44 PM

I have a few questions about the finding. Thanks in advance!

What was the role of MA v. EPA in the Obama EPA's decision to make the endangerment finding?

Do you think that the Obama EPA would have made the finding (or made it as quickly) without the Supreme Court's remand?

David ShimoniApr 18 2009 01:15 AM

Hello Mr. Doniger,
I support NRDC's climate campaign fully and congratulate you on this recent success. However, I do not understand the lack of a gasoline tax in the climate bill. Relying on increased vehicle fuel efficiencies, low-carbon fuel standards and plug-ins to decrease the greenhouse emissions from transportation would seem to continue to hide the consequences of their actions from the gasoline consumers who are a large source of CO2 emissions. Don't we want to externalize environmental costs? Increased fuel standards will probably raise the price of cars (i.e., a fixed cost) but not the price of gasoline (i.e. the marginal cost of transport). How, then will it discourage driving and encourage use of mass transit, which other parts of the climate bill advocate? Will not gas-guzzling SUVS actually command a premium price in this scenario, since the auto companies will be allowed to make fewer of them? Wouldn't a gas tax be a more clarifying price signal to both consumers and producers? Please illuminate.

David DonigerApr 18 2009 11:00 AM

Time to respond to some comments and questions. Keep 'em coming.


We need action by the Obama administration under the existing Clean Air Act at the same time that we need action by Congress to pass a new amendments to the Clean Air Act to comprehensively curb global warming pollution. The EPA can take some big bites out of CO2 and other heat-trapping pollution with standards for new cars, power plants, and other big sources. (Contrary to Chamber scare tactics, there's plenty of leeway to keep the focus on the big stuff -- no one need worry about his barbeque.) But to do this job right, we also need a comprehensive cap and reduction -- at least 20% by 2020 and 83% by 2050 -- which Congress can best provide. In that legislation, Congress can also create the incentives and transition provisions to help all regions of the country meet these goals. Then what EPA is doing, and what Congress is doing, will merge, and the U.S. can be a partner again in the world-wide fight to avoid disastrous climate impacts.


The Supreme Court's decision was critical. As NRDC's lawyer in that case, I know. For six years, the Bush administration denied the Clean Air Act was there to protect against climate change. And for its last two years, they did nothing. But candidate Obama pledged to carry out the current law, as well as ask Congress to add to it with a new cap and reduction program. And that's exactly what he's doing. The Supreme Court decision did more than get it right. It served to crystalize the issue and elevate global warming in our public and political discourse. So, hats off to the Supremes.


We think a cap that declines each year to the targets I mentioned above, and standards for cars, power plants, and some other big sources, is the combination to get the job done. The cap is carried out with pollution "allowances," and they will show us the price of carbon and give businesses and individuals the signals they need to invest in cleaner, greener technology. The cap is key because it guarantees the environmental result. With a tax, you're just guessing. For more on this, see a blog by my colleague Dave Hawkins:

Jeff LassleApr 18 2009 11:52 AM

What this country needs is more lawyers calling themselves scientists. It is a sad day for America when the EPA becomes a political agency reacting to whomever is in charge rather than looking at basic science. First guess is that the liberal left has nothing better to do than to conduct poorly constructed models of climatic changes and give Man credit to the workings of a natural cycle. For a liberal to make a statement that this biosphere can maintain a constant temperature throughout its existence is just rather silly, but the money received by this newly created field, climatology, is not silly and serious money is being given to study the issue. And new Mercedes's and sports cars are being bought and Al Gore lives in a mansion. Since the scientific community no longer considers the "hockey stick" as the rule of thumb but rather CO2 follows the warming of the earth (makes perfect scientific sense) then how come the liberal left continues to change its hypothesis.

This reminds me of a story whereas a Scripts Institute of Oceanography scientist stated in a news publication that within 20 years Lake Mead would be completely dry as a direct result of AGW. Upon being approached within this publication by real scientists, this Scripts scientist reported back that he revised his findings to 50% chance that Lake Mead would be dry in 20 years. Well at those odds, this particular scientist could not lose that bet.

David, I understand you are a lawyer and maybe you should stick to that so-called profession and the NRDC should consider reporting facts instead of spewing left wing agendas. Use your organization to fight real environmental problems such as pollution and help fund those who are looking for better power sources for the future, not for the fallacy of AGW but for the sake of the environment by pollution. The carbon tax, credits, etc. are nothing more than a liberal way of collecting money and does no good for the environment. Look for the solution, not a band-aid.

Finally, stop watching the liberal Hollywood movies on this subject as special effects can and do mold the minds of those in the world who are gullible and consider the Hollywood movies over real science. The earth has been in warming stages before, without the addition of automobiles and power plants so you as a liberal want to change mother nature. A very dangerous thought, indeed.

Climatology is a very young science and it has a lot of learning yet to do before it can be considered factual. Computer based climate models are not accurate and do not encompass the entirety of the complexities of this biosphere. Consider Okham's Razer.

A prosperous nation is a clean nation, please keep that in mind when developing issues that can and will destroy the fabric of this great nation.

David DonigerApr 18 2009 12:43 PM


The great thing about blogging is that is about the only place left where there's any conversation across the political spectrum.

Respect for science isn't, or shouldn't be, a liberal or conservative thing. Facts are stupid -- I mean, stubborn -- things.

Devin McDougallApr 18 2009 02:51 PM

Thanks! My question, though, was more trying to get at the issue of whether the decision in MA v. EPA was specifically necessary for the Obama EPA to have issued the proposed endangerment finding, given that, as you mention, the Clinton EPA’s General Counsel had written a memo in 1998 finding that CO2 was a pollutant according to Clean Air Act section 320(g), and potentially subject to regulation.

Then this was overturned by the Bush EPA in 2003, which argued that CO2 was not a CAA pollutant. The Bush EPA also claimed that even if it did have the authority to regulate CO2 under the CAA, it would choose not to for policy reasons.

The Supreme Court in MA v. EPA held that CO2 was a CAA pollutant, and ordered the EPA to reconsider its regulation decision based on scientific, not policy, criteria.

However, wouldn’t the Obama EPA have reconsidered the Bush EPA’s climate policies even without the Supreme Court order to do so?

Was the key part of the MA v. EPA decision more the holding that policy considerations could not be injected into decisions on whether to regulate CAA criteria pollutants? This could provide some insulation against industry pressure not to regulate, an important benefit, in light of the CPI’s report on the swelling ranks of industry climate lobbyists. This also provides some teeth to the prospect of administrative regulation of CO2, which provides some leverage for passing new climate legislation.

Craig SydneyApr 18 2009 03:08 PM

There is not one bit of scientific evidence to support "global warming" is caused by anything done by humans.This is another well orchestrated political lie, founded on twisted facts.Out of prox. 18,000 of the worlds best SCIENTISTS,not politicians,and from evidence gathered(scientifically)from locations all over the planet(not just in politically chosen areas),not one(let me repeat that,NOT ONE)found
ANY evidence that supports "global warming"as a result of humans.With the proper
political agenda,I could claim,that darkness at night,is caused by CO2 emissions or other forms of pollution,but we all can see how ridiculous that is.We could also see from a ridiculous claim as this,that I had another agenda.Please people,wake-up,these politi-
cians and their so called "experts",are no smarter than the rest of us.Please start thinking for yourselves and verifying these ridiculous political claims,with their hidden agendas.I simply went to the library,and checked out a book"Unstoppable Global Warming"(every 1500 years)and the proof of this political untruth,is supported by thousands of real scientists with scientific evidence,and not political propaganda with an alternate agenda.Al Gore was paid,and paid well,to use his political clout,to further this claim,and remember this important fact,he is ,was and will always be a politician,not a scientist.We as a people need to put the politicians back in........wherever they came from and let the men and women,our scientists,be the voice of science.

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