This graph seems to me to reconcile aspects of legitimate skepticism with a devastating reality. Here’s the earth’s temperatures going back 11,000 years – far further than the 2,000 years previously viewed in popular culture as the “hockey stick”. You can see that stick at the far right of the following graph:

So, yes, the earth has been warmer than it now is while humans inhabited it. Yes, climate has shifted over the millennia, depending on a variety of non-human factors which could also be affecting us now. Yes, in the last half a millennium, we hit what was described as a mini-ice-age, bringing temperatures down to record lows for ten millennia. In 1683, for example, the river Thames was frozen completely for two months. Here’s a painting of the river in 1677, as the Little Ice Age, as we now call it, set in:

I can remember a cover-story in the New Republic predicting a new ice age in the 1980s – based on the long-term chilling of the planet. So you can see why those urging against hysteria have some historical climate variety to argue that change has always been here and that humans have lived on the planet for 2000 years and adapted to similar temperature variations before. So chill out, and keep drilling.

The problem with that reassuring scenario, as Tim McDonnell points out, is that we have never before experienced this sudden rate of heating before ever – certainly not since humans developed agriculture. It’s getting close to a vertical line now, which suggests to me that the likelihood of feedback loops actually intensifying the heat has also gone up.To put it mildly, I can see no external reason why the earth’s temperature would have suddenly gone haywire in the last 500 years, without factoring in carbon, capitalism and the industrial revolution. For a while, that carbon actually warmed us up out of a millennial-long cooling. But now, it’s out of control. And if you begin to imagine the impact of every Chinese or Indian reaching the same level of prosperity as Western Europe, using the same carbon sources of energy, we are clearly putting the planet through a stress test never before imposed by its inhabitants.

To be perfectly frank, this graph shows our civilization to be unsustainable unless we dramatically alter its source of energy. Maybe we can adapt – in ways our ancestors did. But they were able to do so over much, much longer periods of time, and were not actually creating the situation.

We have become gods. And we are destroying what we inherited as a species. I do not have an answer, and suspect only a technological breakthrough in energy resources will make a difference real enough to stop this looming catastrophe. But that this isn’t the priority of every government on Earth right now (apart from Russia and Canada) is beyond me. And a carbon tax – the simplest clearest inhibitor of turning our planet into an oven – would be a start.