The world's ice sheets would be sloughing off massive melting chunks four times the size of Manhattan. The cost of bread would be soaring across the world as heat shrivelled the wheat crops. The increased carbon dioxide in the atmosphere would be fizzing into the oceans, making them more acidic and so killing 40 per cent of the phytoplankton that make up the irreplaceable base of the oceanic food chain. The denialists would be conceding at last that everything the climate scientists said would happen – with their pesky graphs and studies and computers – came to pass.
This is all happening today, except for that final stubborn step. It's hard to pin any one event on man-made global warming: there were occasional freak weather events before we started altering the atmosphere, and on their own, any of these events could be just another example. But they are, cumulatively, part of a plain pattern where extreme weather is occurring "with greater frequency and in many cases with greater intensity" as the temperature soars, as the US National Climatic Data Centre puts it. This is exactly what climate scientists have been warning us man-made global warming will look like, to the letter. Ashen-faced, they add that all this is coming after less than one degree of global warming since the Industrial Revolution. We are revving up for as much as five degrees more this century.
Yet as the evidence of global warming becomes ever clearer, the momentum to stop it has died.
The Copenhagen climate summit evaporated, Barack Obama has given up on passing any climate change legislation, Hu Jintao is heaving even more coal, David Cameron has shot his huskies, and even sweet liberal Canada now has a government determined to pioneer a fuel – tar sands – that causes three times more warming than oil. True, the victims are starting to see the connections. The Russian President, Dmitri Medvedev, had been opposed to meaningful action on global warming until he found the smoke-choked air in the Kremlin hard to breathe. But if we wait until every leader can taste the effects of warming in their mouths, the damage will be irreparable...
Johann Hari: How much proof do the global warming deniers need? - Johann Hari, Commentators - The Independent