The last time America was this climate-friendly, carbon dioxide wafted up from smokestacks to the smooth sounds of All-4-One and Boyz II Men.
Not since 1994 have U.S. CO2 emissions been as low as they were in 2012, according to a new report by Bloomberg New Energy Finance. Output of the heat-trapping gas fell 13 percent in the past five years, putting the country well on its way to meeting President Obama's target of cutting emissions 17 percent from 2005 levels by 2020. By the end of last year, U.S. CO2 emissions were already down 10.5 percent from the 2005 baseline.
While economic woes have helped suppress global CO2 emissions in recent years, that trend has already begun to fade. And as Bloomberg analysts see it, America's 2012 dip is much bigger than some statistical blip or side effect of the recession.
"A revolution is transforming how Americans produce, consume, and even think about energy," BNEF explains in an executive summary of the new report. "Traditional sources are in decline, while natural gas, renewables and energy efficiency are on the rise. These changes, which show no sign of abating, have far-reaching implications for U.S. economic and national security interests. They are increasing the diversity of the country's energy mix, improving our energy security, and rapidly shrinking our 'carbon footprint' — a major positive development for addressing climate change."
This shift is unfolding on several fronts. For one thing, the U.S. has become increasingly efficient lately, pushing down its total energy use by 6.4 percent from 2007 to 2012, even as GDP grew 3 percent in the same period. The country's energy portfolio is also changing, making Americans less reliant on carbon-heavy fuels like coal and petroleum. Coal represented just 18.1 percent of all U.S. power sources in 2012, down from 22.5 percent in 2007, while slightly cleaner natural gas has surged in popularity, thanks largely to the advent of hydraulic fracturing. Gas-fired power plants supplied 31 percent of U.S. electricity in 2012, according to BNEF, up from 22 percent five years ago.
While natural gas releases less CO2 than coal and oil, though, it's still dogged by problems like methane emissions and water pollution, not to mention its volatility in pipelines. It's often referred to as a "bridge fuel," and as BNEF notes, the U.S. energy sector is starting to focus not just on the bridge itself, but also where it leads. U.S. generation of clean, renewable energy has grown from 8.3 percent to 12.1 percent since 2005, representing "the largest single source of new capacity growth in 2012," according to the report.
U.S. energy-related CO2 emissions, 1974-2012 (in million metric tons):
U.S. electricity generation by fuel type, 2007-2012 (in percentage):
All this bodes well for Obama's credibility on climate policy, especially after the failure of cap-and-trade legislation in 2009 and the prolonged suspense over the Keystone XL oil pipeline. It could also help at U.N. climate talks, giving U.S. diplomats something to point to when negotiating with carbon-intensive developing nations like China, India and Brazil.
But despite recent progress, the overall problem remains enormous. The U.S. is still No. 2 worldwide in net CO2 emissions, trailing only China, and is still No. 10 per capita. Global emissions have also soared in recent years as economies recover, and as the accounting firm PricewaterhouseCoopers reported in November, even today's notable successes aren't nearly enough to prevent climate disasters down the road.
"It's time to plan for a warmer world," PwC partner Leo Johnson wrote in the report's introduction. "Even doubling our current rate of decarbonisation would still lead to emissions consistent with 6 degrees (Celsius) of warming by the end of the century. To give ourselves a more than 50% chance of avoiding 2 degrees (Celsius) will require a six-fold improvement in our rate of decarbonisation."
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