We all know the Earth is getting warmer. Everyone except Republicans knows the increase in temperature is related to carbon emissions from burning fossil fuels. Climate scientists don’t agree on how much average global temperatures will rise. Their best guess is they could go up as little as 1.5º Celsius or as much as 4.5º Celsius (2.7º to 8.1º Fahrenheit).
New research led by professor Peter Cox at the University of Exeter in the UK suggests that the range of likely temperature increase will fall between 2.2º C and 3.4º C, with the most likely number being 2.8º C. In a paper published in the journal Nature Climate Change entitled “Emergent constraint on equilibrium climate sensitivity from global temperature variability,” Cox and his colleagues say they have used new modeling techniques to eliminate the high and low points from current climate models and come up with a range of numbers they believe more accurately predict how much warming will occur. “Our study all but rules out very low and very high climate sensitivities,” Cox says.
The research focuses on a concept known as equilibrium climate sensitivity, which Cox and his colleagues define as “the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level of CO2.” The new research places more emphasis on historical climate data, which indicate the Earth is better able to handle changes in carbon dioxide levels without going into meltdown mode than previously thought.
Two climate scientists who were not involved in the research have commented on the results. “These scientists have produced a more accurate estimate of how the planet will respond to increasing CO2 levels,” Piers Forster, director of the Priestley International Center for Climate at the University of Leeds, tells The Guardian. Gabi Hegerl, a climate scientist at the University of Edinburgh, adds, “Having lower probability for very high sensitivity is reassuring. Very high sensitivity would have made it extremely hard to limit climate change according to the Paris targets.”
So, is it time to uncork the champagne, heave a big sigh of relief, and tell the fossil fuel companies to “Drill, baby, drill?” Actually, no. A rise in global average temperatures of 2.8º C will still be a disaster for the earth and every living thing on it. The extinction of existing species will continue, ocean levels will still rise significantly, and drought will force many millions of people to become climate refugees. “We will still see significant warming and impacts this century if we don’t increase our ambition to reduce CO2 emissions,” says Piers Forster.
The world is already well on the way to the 1.5º C plateau, which has been enough to cause the Arctic ice sheet to melt and weather patterns around the world to shift — drier in some locations, wetter in others. More frequent and more violent storms are occurring, along with intensified forest fires in some locations. Even if Cox is correct, adding another 1.3º C on top of the temperature rise that has already occurred will cause unimaginable changes to the earth’s ecosystems.
The report is comforting. The worst case scenario the world has been fretting about for decades may not come to pass after all. But there is a latent danger associated with this study. The climate denial industry — and it is an industry — could easily seize upon these findings and use them to justify ignoring carbon emissions entirely. They could be fodder for the automakers who resist higher fuel economy and emissions standards, the fracking companies who insist that a few methane leaks never hurt anybody, and all the other business interests who depend on fossil fuels for their livelihood. Expect it to be used to argue against climate action of any sort.
It may be true the Earth isn’t headed for a catastrophic climate event, but that doesn’t mean humanity should continue using the home that sustains us all as a cesspool with no thought of future consequences.