CHAPEL HILL — The earth is cooling!"
Actually it isn't, but we have all heard that so many times recently, we're starting to wonder.
Globally, the last few years have indeed been cooler than 1998 and 2005. But this has no relevance for whether the planet's climate is changing or whether people are the cause. The unemployment rate dipped this summer too, but would anybody credibly argue that was evidence unemployment hadn't risen during and as a result of this recession?
According to NASA, the hottest 10 years since 1880 (when continuous instrument records begin) have occurred since 1996, and the planet's temperature is still increasing. The only way to arrive at the conclusion that global warming has plateaued, as syndicated columnist George Will has suggested, is to begin your analysis in 1998 -- the warmest year on record. In science, the technical term for choosing your data to make a point is "cherry picking."
Like many climate-change skeptics, Will is confusing weather with climate, which encompasses longer time periods, generally 30 years or more. The shorter-term fluctuations he frets about are natural, have been happening for centuries, are well understood by climate scientists and are predicted by global climate models. It is the longer-term progressive warming that began over a century ago -- and coincides with the buildup of greenhouse gases in the atmosphere -- that is cause for concern.
Climate-change skeptics are successfully making the public think the evidence of our impact on the Earth's climate is confusing and contradictory. The details are complicated, but the basic science is actually simple. Have you ever climbed into a closed car on a sunny August afternoon? Pretty hot wasn't it? That is essentially what the growing layer of gases in the atmosphere does to the Earth, trapping in the heat caused by the sun warming up the land, just like it warms up the dashboard in your car.
Here in the world's wealthiest nation the impacts of climate change on most of our lives have been relatively minor. Elsewhere, crops are failing, temperature-sensitive diseases like malaria and cholera are increasing and coastal villages are preparing to move to higher ground. Here, arguing about whether the Earth is warming is political sport. Elsewhere, the argument has moved on to which new technologies might reverse climate change, how societies can adapt to it and who should pay for the costs.
When a coral reef in Papua New Guinea is wiped out by warming oceans, local fisheries collapse and fisherman can't afford to send their kids to school. When Arctic permafrost melts, the physical underpinning of entire Alaskan villages is endangered. Nearly 1 billion people, or 1 in 7 worldwide, live at low coastal elevations and are experiencing flooding, erosion and other direct impacts of climate change.
We haven't experienced impacts of that scale here in North Carolina, but we eventually could. As sea level continues to rise, coastal communities here, too, will be threatened, and economies based on tourism and agriculture will suffer. Some of our fisheries could be affected too. One of the many effects of increasing the concentration of carbon dioxide in the atmosphere is that the oceans are becoming more acidic. This will affect economically important marine life like shrimp, crabs and oysters by making their skeletons more brittle and harder to grow.
Given the clarity and relative certainty of the science, and the scale of the potential social and economic impacts, why do newspapers publish opinion pieces denying that climate change is happening? Social commentators like George Will certainly have freedom of speech and a general license to express their opinions on the editorial page. But would editors publish essays denying other major threats to humanity?
In some countries, you actually do see such lies in the media. To Americans, this seems crazy, which is what the rest of the world thinks when they read denials about global warming in our newspapers. To everybody else, climate change is something they are already experiencing and are trying to find solutions to, rather than just another talking point in a never-ending culture war.
John Bruno is an associate professor in the Department of Marine Sciences at UNC-Chapel Hill. Mark Sorensen is an associate professor in the Department of Anthropology at UNC-Chapel Hill.