For environmental wonks like me, one of the biggest casualties of the government shutdown was the brief loss of the U.S. Energy Information Administration (EIA), the invaluable federal agency that crunches detailed statistics on U.S. and international energy use. Thankfully the EIA came back online with the rest of the government last week, and today it released a new report finding that U.S. energy-related carbon dioxide emissions declined by 3.8% in 2012 to reach the lowest level since 1994. Energy-related CO2 emissions are now down over 12% since the prerecession peak in 2007 — and remarkably, emissions have kept dropping even as the economy has continued to grow, albeit slowly:
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A few other takeaways from the EIA report:
- Climate change may have helped reduce carbon emissions: About half of the overall decline in energy consumption came in the residential sector. And some of that decline was due to an incredibly warm winter in 2012, which led to a 22% reduction in cumulative heating degree days compared with 2011. Warmer weather means less demand for heating, which in turn reduces energy consumption — at least in the winter.
- Energy efficiency rules the day: The single biggest factor in the emissions drop was a more than 5% decrease in the energy intensity of the U.S. economy — the amount of economic value it gets per unit of energy. That’s largely about energy efficiency, as businesses and households reduce energy waste, though the long-term shift from energy-intensive manufacturing to an economy based around energy-light services and technology helps as well. Industrial output was 2.7% lower in 2012 than in 2007, and manufacturing output was 5% lower in 2012 than in 2007.
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- More reasons to pay attention to carbon intensity: Another way to look at this critical metric is how much carbon dioxide is emitted per million dollars of economic value. Getting more energy-efficient and taking the carbon out of your energy supply — by switching to cleaner fossil fuels like natural gas or carbon-free sources like renewables or nuclear — reduces carbon intensity. According to the EIA, in 2012 carbon intensity fell to 389 metric tons per million dollars — the lowest level on record, going back to at least 1949.
- Fracking is winning, and coal is losing: That’s the big story in U.S. energy generation, and it accounts for much of the fall in carbon emissions. The U.S. produced 215.2 billion kilowatt-hours less of electricity from coal in 2012 — and 211.8 billion kilowatt-hours more of electricity from natural gas, thanks chiefly to cheaper shale gas. Though experts disagree on the specifics, the Environmental Protection Agency calculates that natural gas has about half the carbon footprint of coal. More gas plus less coal equals less CO2.
- We drove less and got more mileage when we did: I’ve written before that the U.S. may have already reached “peak drive,” as fewer and fewer people choose to drive regularly, and drive less when they do. Total vehicle miles traveled in 2012 were 3.3% lower than in 2007, and vehicle fleet efficiency is up 16% over those same years, thanks to tougher gas-mileage standards and persistently high fuel prices. Given that transportation is the second biggest source of CO2 emissions after industry, driving less and driving efficiently add up.
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