Natural disasters? (from: http://www.guardian.co.uk/world/2011/apr/02/natural-disasters-floods-earthquakes-landslides)

Floods, earthquakes, landslides: 2011 is a year of disasters. Bill McKibben asks: are we to blame?

At least since Noah, and likely long before, we've stared in horror at catastrophe and tried to suss out deeper meaning – it was but weeks ago that the Tokyo governor, Shintaro Ishihara, declared that the earthquake/tsunami/ reactor tripleheader was "divine punishment" for excess consumerism. This line of reasoning usually fails to persuade these days (why are Las Vegas and Dubai unscathed by anything except the housing meltdown?) but it's persistent. We need some explanation for why our stable world is suddenly cracked in half or under water. Still, over time we've become less superstitious, since science can explain these cataclysms. Angry gods or plate tectonics? We're definitely moving towards natural explanation of crises.

Which is odd, because the physical world is moving in the other direction.

The Holocene – the 10,000 years through which we have just come – was by all accounts a period of calm and stability on Earth. Temperatures and sea levels were relatively stable. Hence it was an excellent time to build a civilisation, especially the modern kind that comes with lots of stuff: roads, buildings, container ports, nuclear reactors. Yes, we had disasters throughout those millennia, some of them (Krakatoa, say) simply enormous. Hurricanes blew, earthquakes rocked. But they were, by definition, rare, taking us by surprise – freaks, outliers, traumas that persisted in our collective history precisely because they were so unusual.

We're now moving into a new geological epoch, one scientists are calling the Anthropocene – a world remade by man, most obvious in his emissions of carbon dioxide. That CO₂ traps heat near the planet that would otherwise have radiated back to space – there is, simply, more energy in our atmosphere than there used to be. And that energy expresses itself in many ways: ice melts, water heats, clouds gather. 2010 was the warmest year on record, and according to insurers – the people we task with totting up disasters – it demonstrated the unprecedented mayhem this new heat causes. Global warming was "the only plausible explanation", the giant reinsurer Munich Re explained in December, of 2010's catastrophes, the drought, heatwave and fires across Russia, and the mega-floods in Pakistan, Australia, Brazil and elsewhere were at least plausibly connected to the general heating. They were, that is to say, not precisely "natural disasters", but something more complex; the human thumb was on the scale.

We still have plenty of purely natural disasters – though scientists can posit reasons climate change might make the world more seismically active, tectonic and volcanic forces seem beyond our reach; the great wave that broke over Sendai really did come out of the blue. But even in Japan, of course, the disaster was not entirely "natural". The subsequent fallout was… fallout, the invisible plume streaming from one of our highest-tech marvels, a complex reduced in minutes into something almost elemental, a kind of utility-owned volcano.

In a sense Ishihara was correct when he decried "selfish greed". It is consumerism that has flooded the atmosphere with CO₂: the constant getting and spending, where $1 spent liberates roughly 1lb of carbon. We are remaking the world, and quickly; we are stumbling into a new way of thinking about disaster, where neither God nor nature, but man is to blame.

That changes the valence of catastrophe. Since warm air holds more water vapour than cold, the atmosphere is nearly 5% moister than it was just a few decades ago. That loads the dice for great floods of the kind suddenly so common. I lived through one in my small mountain town in Vermont two summers ago: the biggest thunderstorm in our history dropped buckets of rain in a matter of hours. Our town is almost entirely intact forest; it should have been able to hold whatever nature threw at it. But that rain fell on a different planet from the one the forest had grown up on; every road washed out, and the governor had to visit by helicopter. But at least we had the solace (or self-lacerating realisation) that we'd helped cause this deep change. Americans burn more carbon per capita than just about anyone; what do you say to a Pakistani farmer watching the swollen Indus wash away his life's work? And since global warming seems to take first aim at the poorest places that have done the least to cause it, this is a question we may be asking ourselves a good deal in the decades to come.

Not every natural disaster is unnatural now, and we may be able to fool ourselves a little longer. But these days it's the climate deniers who act like the pious of yore, unable to accept the truth. I was surprised, and impressed, to read a poll of Americans taken recently. By healthy majorities, this most religious of western citizenries said natural disasters were more likely to be a sign of climate change than of God's displeasure.

Which is good news, because for the first time in human history we can prevent a great deal of unnecessary cataclysm in the years ahead. Not all of it – there will always be earthquakes and hurricanes. But every bit of carbon we keep out of the atmosphere is that much less extra energy we add to the system. It's that much less disaster waiting to happen.