If you spend any time keeping up with the news on climate change, or even just looking at the occasional graph or two, it’s hard not to come to the reasoned, scientific conclusion that we are, in fact, totally fucked.

Scientists now think that by the end of the century, the planet is very likely to be four degrees Celsius warmer than it was at the start of the industrial revolution — a difference equivalent to that between now and the last ice age — and possibly much more. Even in a mid-range emissions scenario, temperatures could rise by three degrees by the middle of the century. The effects of global warming are already materializing more quickly than expected; it seems that every day a new report emerges declaring that all previous bleak predictions actually underestimated how bad things are, and how soon they will get worse.

Where we used to speculate in terms of centuries and future generations, we now speak of decades and the fate of those already living. We’re treading on treacherous ground, marked by thresholds we may have already crossed and negative feedback loops whose trigger points we don’t understand. A certain amount of warming is already assured, though we’re not sure how much; the window to prevent the certainty of more is rapidly closing. Environmentalism has long been the bearer of bad news and the trumpeter of end times, but this time the wolf really seems to be at the door: if not quite end-of-civilization territory, it’s frighteningly close. After years of putting on a brave face so as not to scare the public into fatalism, even scientists are starting to freak out.