Humans cause climate change. Scientists agree we do. This is not news. The fact that they agree was itself first scientifically established back in 2004, when a survey of 928 published papers (pdf) on climate science found not a single one that disputed the consensus. A more recent survey of over 12,000 papers found 97% support among those that took a position.
Yet this week many of the headlines about the latest report from the Intergovernmental Panel on Climate Change—itself just a survey of the scientific literature—were about its finding that scientists are now even more certain that mankind causes global warming.
It’s as if an ever-so-slightly less equivocal scientific consensus might somehow sway the deniers or tip the balance for policymakers. But given past experience, it clearly won’t. Nor will the IPCC’s warnings that temperatures will likely increase, seas rise, and ice-sheets melt even faster than previously thought. Which raises the question: What is the IPCC for, other than to hammer home what’s already to known to those who already know it?
Perhaps, then, the IPCC should broaden its mission: to investigate and publicize the secondary consequences of climate change. This week, for instance, Quartz reported on the plague of Asian hornets that have killed 28 people in China this summer, and are proliferating due to rising winter temperatures. They’re now spreading rapidly in Europe too, where not only people are vulnerable, but also the honeybees on which so much agriculture depends.
Direct proof of such impacts of climate change is often hard to establish. But science exists to solve hard problems. To skeptics and politicians, slowly rising seas and gradually retreating glaciers are easy to ignore. Giant killer hornets: not so easy.—Gideon Lichfield