Climate 411

Environmental Groups Put EPA on Notice

By Bill Chameides / Published: May 22, 2007

In 2005, California petitioned the U.S. Environmental Protection Agency (EPA) for permission to establish its own, stricter tailpipe emissions standards. Nearly two years have passed, and EPA still has not ruled on the request – despite a recent Supreme Court ruling that EPA has the authority to regulate tailpipe emissions.

Today, Environmental Defense and NRDC sent a letter to EPA warning that they will join California to in a lawsuit to compel "EPA’s unreasonably delayed and unlawfully withheld final action on California’s waiver request" if the agency does not make a decision within 180 days.

Also posted in Cars and Pollution, Clean Air Act, EPA litgation / Read 1 Response

What is a Carbon Footprint?

By Bill Chameides / Published: May 10, 2007

You hear a lot of talk these days about "carbon footprints". But what is a carbon footprint, anyway?

Carbon dioxide (CO2), while not the only greenhouse gas, is the most abundant. CO2 is emitted into the atmosphere when we burn fossil fuels, and most of the energy in this country comes from burning fossil fuels. Thus, anything that requires energy to manufacture, transport, or operate causes the emission of CO2 (see my previous post, The Carbon Footprint of… Everything).

A "carbon footprint" is the amount of CO2 released by an activity or entity. So what’s your carbon footprint?

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Also posted in Economics / Read 12 Responses

Slicing the greenhouse gas pie: Where from?

By Bill Chameides / Published: April 26, 2007

In the previous post, I described which gases are important and what activities they come from. But we can also learn a lot by looking at regional patterns in how those gases are emitted.

For example, most deforestation occurs in poor tropical countries (in fact, in many of these countries deforestation is a much larger source of CO2 than fossil fuel use). In contrast, most CO2 emissions from fossil fuel use come from the developed countries.

As I described in an earlier post, the U.S. is the largest emitter in the world, both today and historically. Next let’s take a closer look at the U.S. greenhouse gas pie.

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Posted in Greenhouse Gas Emissions / Read 5 Responses

Slicing the greenhouse gas pie: What gases?

By Bill Chameides / Published: April 26, 2007

We keep talking about the need to reduce the greenhouse gas we produce. But how do these gases get in the atmosphere? To answer that question we need to look at what I like to call the “greenhouse gas pie,” and it turns out there are lots of ways to slice it up.

One way is to slice the pie up by the type of gases we’re talking about. There are dozens of human-produced greenhouse gases, three of them get special attention: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Here’s why.

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Posted in Greenhouse Gas Emissions / Read 6 Responses

Supreme Court Reverberations

By Bill Chameides / Published: April 9, 2007

Last week’s Supreme Court ruling on Massachusetts versus EPA was a landmark victory for Planet Earth, but there’s still much work to be done. The ruling doesn’t demand any specific action – it just sets the stage for future rulings. Case in point: California’s petition to EPA to use its own, stricter emissions standards rather than federal emissions standards.

In light of this ruling, will the EPA grant California’s petition? On April 5th, a couple of news outlets reported that EPA had approved California’s request. Unfortunately, they got it wrong. EPA simply agreed to take the next to step in considering the California waiver – holding public hearings. We won’t know for months how EPA will rule.

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Also posted in Cars and Pollution / Read 4 Responses

Part 3 of 4: U.S. Emissions Target

By Bill Chameides / Published: March 21, 2007

This is the third installment of a four-part series to be published each Wednesday on Action Needed to Stop Global Warming.

1. How Warm is Too Warm?
2. Worldwide Emissions Target
3. U.S. Emissions Target
4. Technologies to Get Us There

In Part 1 of this series, I defined the global tipping point as the melting of the Greenland ice sheet, which could cause sea levels to rise 20 feet. In Part 2, I showed by how much global emissions of carbon dioxide (CO2) must drop to avoid this tipping point. They must start to decline around 2020, drop 50 percent by 2050, and drop at least 75 percent by the end of the century.

Meeting these global emissions targets will require a global effort. Even if the U.S. and other developed countries were to cut their emissions to zero, global emissions would likely exceed the targets by mid-century. This is because of the rapid rise in emissions from China and other developing countries.

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Also posted in Basic Science of Global Warming / Read 8 Responses