Carbon emissions: Trend improves, but …

Sometimes what’s bad for the economy can be good for the planet. Or so argued Lester Brown, president of Earth Policy Institute, yesterday. This environmental trend spotter pointed to several developments that may have escaped our attention as the global economy alternately sputtered and entered periods of freefall throughout the past 18 months.

Trend one: U.S. emissions of carbon dioxide, a leading greenhouse gas, have taken a tumble. They’re down 9 percent since 2007, Brown notes, fueled in part by a couple other developments.

Such as trend two: Americans are buying/keeping fewer cars. During the mid- to late-1990s, automakers sold more than 15 million cars a year. “Then, in 1999, [sales] jumped up to 17 million a year, and remained there for about eight years or so,” Brown says. This year: Those sales slumped to a measly 10 million. Meanwhile, U.S. motorists are on track to scrap about 14 million cars this year. So the U.S. fleet could shrink this year by nearly two percent.

Trend three: New cars tend to have a smaller carbon footprint than those now being scrapped — a trend that will only continue. There is already a rapidly expanding population of gas-sipping hybrids on the roads, and some moderately affordable, super-efficient electric and plug-in hybrids are slated to roll off assembly lines in about a year. (To help consumers find out how various cars compare in their fuel economy, the Environmental Protection Agency today released its 2010 passenger-car mileage guide.) And by 2016, thanks to a new White House policy issued in May, new U.S. cars must get an average 35.5 mpg. That’s four years earlier than the 2007 Corporate Average Fuel Economy law would have driven such a 40 percent boost in average mileage.

Trend four
: The weight of U.S. cars has been diminishing as increasing amounts of steel have been replaced with lighter-weight structural materials. The result: “The amount of steel in the cars being retired is at least 40 percent larger than in the new cars being sold.” That’s contributing to a “steel surplus,” Brown says. Virtually every gram of steel in a retired car is recycled, he explains. Because it requires only about one-third as much energy to reuse steel than to produce it from scratch, pre-owned steel not only costs less but also contributes far fewer carbon emissions to the atmosphere.

Trend five: Phasing in considerably lighter, fuel-efficient cars might help the United States ditch its reputation as the world’s marathon gas guzzler. Currently, Brown notes, “the United States consumes more gasoline than the next 20 countries combined.” Already, the smaller, lighter U.S. fleet and recent reductions in annual driving distances per household have contributed to a drop in U.S. oil consumption. It fell five percent last year, Brown notes, and another five percent this year.

Trend six: Also contributing to the downturn in U.S. carbon emissions has been a drop in domestic coal consumption. This fuel is plenty dirty as it’s burned today, spewing huge quantities of carbon dioxide and other pollutants. Increasingly, communities have been rebelling at the idea of a new soot-belching generating station being sited in their backyards. The result, Brown reported yesterday, coal use fell one percent last year and another 10 percent this year. Another telling stat: “In July,” he says, “the Sierra Club — coordinator of the national anti-coal campaign — announced the hundredth cancellation of a proposed [coal] plant since 2001. This battle is leading to a de facto moratorium on new coal plants.”

Brown acknowledges that most of these trends reflect America’s sour economy. But he also sees signs that some of these trends might continue, if not quite at the same dramatic pace. Many utilities are investing in renewable energy sources for an increasing share of their electricity generation and many companies are choosing to make their production processes less carbon intensive and polluting.

Concludes Brown: “For years we’ve been hearing that it’s difficult, if not almost impossible, to substantially cut carbon emissions. In fact, it’s not all that difficult.”

Ummmm. I think millions of out-of-work Americans and huge numbers of companies in receivership would argue otherwise. It’s been a very painful and difficult transition.

And the worst is yet to come, Brown and others concede.

In December, formal negotiations commence on a successor treaty to the Kyoto Protocol, that ill-fated blueprint for limiting the release of carbon dioxide and other climate-warming pollutants. The new treaty’s crafters face a tough challenge.

On Sept. 29, White House science adviser John Holdren noted that the best available data from Earth and atmospheric scientists indicate that to prevent wholesale havoc as the planet warms, “global emissions of carbon dioxide and other heat-trapping pollutants should level off by about 2020 and shrink thereafter to something like 50 percent of the current levels by 2050.”

Brown, in his new book — Plan B 4.0 (W.W. Norton: New York, released Oct. 5) — argues that what Holdren outlined constitutes an anemic goal. Earth is already running a small fever, and to prevent it getting dangerously higher, nations “need to cut net carbon dioxide emissions 80 percent by 2020,” Brown contends.

If carbon emissions dropped only 10 percent — despite the help of the worst economy since the Big Depression — how is the world going to average changes eight times that big over the next decade? “Turning this situation around will take a worldwide, wartime-like mobilization,” Brown predicts in chapter 10 of his new book. That sounds like it’s going to be pretty difficult and painful.

Unfortunately, nature is increasingly suggesting that dramatically cutting energy use and pollution may also be non-negotiable.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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