The United States gave Old King Coal a bloody nose last week, with proposals to regulate fossil-fuel emissions that would effectively ban new coal-fired power plants as long as they could capture and store carbon dioxide.
Don’t be equipped with the technology to do it. In the short term the impact may be minimal: opposition to plans for separate new coal power stations and the dash for shale gas as an alternative energy source have forced coal back into the energy pecking order.
But, with federal inaction on the climate change question likely to continue, the Environmental Protection Agency’s move is a welcome one. The agency is finally using the power granted by the Supreme Court in 2007 to treat carbon dioxide as a pollutant.
At the same time, the United Kingdom, which likes to think of itself as an international leader on global warming, seems to be weakening its resolve at home.
The Conservative-Liberal Democrat coalition has loosened similar plans to restrict greenhouse-gas emissions from gas-powered electricity generation, although rules effectively enforcing carbon capture at new British coal power stations remain in place. And, given the government’s concomitant failure to announce new mandatory carbon reporting for British business, as required by the Climate Change Act of 2008, it is clear that voters in the UK were told that they had to Green government.
As the politics of global warming swirl, climate science moves on. This week, two papers in Nature outline what we thought we knew about the problem, as well as offer such surprising results that show why research should continue to accelerate.
First, as Jeremy Shakun and his colleagues at Harvard University in Cambridge, Massachusetts show on page 49, carbon dioxide increases atmospheric warming. Noncontroversial things, perhaps, are nonetheless questioning the link by those who would reduce the risk of human greenhouse-gas emissions.
Questions resurfaced in 2006, when former US Vice President Al Gore showed a graph of historical carbon dioxide levels and temperatures in his film, An Inconvenient Truth, and was accused of shedding light on the relationship between the two.
So there should be no confusion: The new study confirms that, as Earth emerged from the last ice age about 19,000 to 10,000 years ago, rising global temperatures preceded an increase in global carbon dioxide in the atmosphere. was – a result that emphasizes the role of carbon dioxide in driving global change in the present day. This relationship is a cornerstone of climate science and policies to regulate greenhouse-gas emissions, and it is solid.
Quayle Surprise! Climate skeptics may chime in—scientists find proxy data and use computer models to seal the plot, in order to get the answers they want. Then show this week’s second paper shows that modern science is anything but self-serving results to support existing ideas. In a paper published online, Ben Booth at the Met Office Hadley Center in Exeter, UK, and his colleagues used a different model to question conventional wisdom on how the climate of the North Atlantic Ocean operates (BBB Booth et al. al. Nature http://dx.doi.org/10.1038/nature10946; 2012).
This study looks at the effect of aerosols – such as sulfur dioxide particles ejected by volcanoes and those associated with the burning of coal – on sea surface temperatures. Aerosols that reflect sunlight and can promote brighter cloud formation have been known to affect climate for some time, but the idea has gained traction in the media under the tag ‘global dimming’ during the past decade. Appeal has been received.
The study suggests that the warm and cool periods observed in the North Atlantic Basin over the twentieth century may have led to global dimming – a variability known as the Atlantic Multidecadal Oscillation (AMO). And because AMOs have been implicated in global processes, such as the frequency of Atlantic hurricanes and droughts in the Sahel region of Africa in the 1980s, the findings expand the potential reach of human activity on global climate.
Furthermore, if true, the study effectively dispels AMO as it is currently believed, in which multidecade oscillation is neither truly oscillatory nor multidecadal.
This has great implications for both the study of the climate system and the impact of policies to control aerosol emissions. It also shows that solid science doesn’t necessarily need systematic science, and that’s not a bad thing.