
In recent years, it has become increasingly common to frame the climate change problem as a kind of countdown each year we emit more carbon dioxide, narrowing the window for fixing the problem, but notquite closing it yet. After all, something could still change. Emissions could still start to plunge precipitously. Maybe next year.
This outlook has allowed, at least for some, for thepreservation of a form of climate optimism,in which big changes, someday soon, will still make the difference. Christiana Figureres, the former head of the United Nations Framework Convention on Climate Change, recently joinedwith a group of climate scientists and policy wonksto statethere are 3 years left to get emissions moving sharplydownward. If, that is, were holding out hope oflimiting the warming of the globe to below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial temperatures, often cited as the threshold where dangerous warming begins (although in truth, thats a matter of interpretation).
Yet a battery of recent studies call into questio n even that limitedoptimism. Last week, a group of climate researcherspublished researchsuggesting the climate has been warming for longer than we thought due to human influences in essence, pushing the so-called preindustrial baseline for the planets warming backwards in time. The logic is clear: If the Earth has already warmed more than we thought due to human activities, then theres even less remaining carbon dioxide that we can emit and still avoid 2 degrees of warming.