U.S. Emissions Reach 20-year Low, But We Still Have Work To Do

Climate scientists are getting their fair share of surprises this year, from the record-breaking ice melt in the Arctic to the fact that first-quarter U.S. carbon dioxide (CO₂) emissions have hit their lowest point since 1992. CO₂ emissions from energy consumption for the January-March period fell to 1.34 billion metric tons, down 8 percent from a year ago. While the depressed economy and rising renewable energy generation have contributed to emissions reductions in the past few years, the early 2012 low-point is due mainly to a combination of three factors: the relatively warm winter, reduced gasoline demand, and the continued decline in coal-fired electricity.

The declining demand for coal power is especially significant. Although emissions from natural gas and petroleum each dropped nearly 3 percent from the same period in 2011 (mainly because of lower heating demands in the mild winter), coal emissions fell 18 percent, to their lowest point since 1986.

The first half of 2012 also saw significant additions of new renewable energy capacity, although natural gas plants accounted for the vast majority of new capacity in states that traditionally rely on coal power. The low price of natural gas, bolstered by the U.S. shale gas boom, has driven many power producers to shift from dirtier coal generation to cleaner natural gas-fired power plants. When burned, natural gas emits around half of the CO₂emissions as coal combustion.

But it’s not time to sit back on our “we-just-solved-climate-change” laurels just yet. A recent article in Yale Environment 360 cautions strongly against getting caught up in a frenzy of U.S. natural gas development. The authors, researchers at the Colorado-based Renewable and Sustainable Energy Institute, argue that throwing all of the nation’s weight behind a natural gas-centric power sector could risk price increases for gas, and that banking heavily on high estimates of recoverable gas reserves links U.S. fuel security to very uncertain assumptions.

While replacing coal-fired generation with natural gas-fired power is certainly a first step toward climate change mitigation, it is important to ensure that natural gas and renewable energy generation become cooperative, not competitive, as both sectors grow.

It’s also important to consider the decline in U.S. CO₂ emissions in a global context. Even though U.S. emissions may have dropped significantly, China’s energy demand and emissions continue to grow. Declines in 2011 emissions in both the United States and Europe were negated as global emissions rose 3 percent to an all-time high of 34 billion tons. And while total U.S. CO₂ emissions may be at a low, U.S. emissions per capita are still well above most of the rest of the world. In 2011, the United States produced 17.3 tons of CO₂per capita, compared to China’s 7.2 tons.

In the environmental arena, one learns to celebrate the small victories—and this certainly counts. Replacing coal generation with natural gas is arguably a step in the right direction in achieving a clean energy sector, but it will not be the end-all-be-all of climate change solutions. Rather than throwing all of our efforts into natural gas generation, we must focus on developing natural gas resources in conjunction with, and in support of, renewable energy. Cooperation between the two sectors is vital to creating a stable clean energy system and reducing emissions on more than a temporary basis.