The heat’s beginning to get to us

How seriously should we take scepticism over global warming and climate change? “Two per cent of climatologists can’t be wrong,” as the joke goes, deftly making the point that while there are still some who question the evidence — and so give succour to the world’s carbon-producers — the majority of learned observers have no such doubts. The latest section of data to support those concerned by the uncertain consequences of climate change is published this week in Nature. It comes from 740,000 years ago, in sections of ice drilled from three kilometres below the surface of Antarctica over the past eight years.

At first glance the evidence from the ice column… reveals a record of the world’s climate that alternates between ice ages and temperate periods of warmth called “interglacials”. The good news is that if the current interglacial lasts as long as the period in the past that most closely matches our own, then we perhaps have 15,000 years before the next ice age. But the more worrying discovery is the analysis of air bubbles from the ice, which found fluctuating but stable amounts of carbon dioxide — until the beginning of the industrial revolution, when the amount of carbon dioxide started to rise sharply. It is now at by far the highest level on record. Given the link between increases in greenhouse gases and global warming, the current rate of increase in greenhouse gases is 100 times faster than the environmental records revealed by the ice core, and suggests that climate change is on the way.

Excerpted from a leader in ‘The Guardian’, June 11