The last two centuries have seen the biggest rise in greenhouse gases in 800,000 years, according to a study of the oldest Antarctic ice core. Air bubbles trapped in ice for hundreds of thousands of years have revealed that humans are changing the composition of the atmosphere in a manner that has no known natural parallel.
Eric Wolff of the British Antarctic Survey who undertook the research said: “Over the past 200 years, human activity has increased carbon dioxide to well outside the natural range and we have no analogue for what will happen next”.
The core shows that carbon dioxide was always between 180 parts per million (ppm) and 300 ppm during the 800,000 years. However, now it is 380 ppm. Methane was never higher than 750 parts per billion (ppb) in this timescale, but now it stands at 1,780 ppb.
But the rate of change is even more dramatic, with increases in carbon dioxide never exceeding 30 ppm in 1,000 years — and yet now carbon dioxide has risen by 30 ppm in the last 17 years. “The rate of change is probably the most scary thing because it means that the Earth systems can’t cope with it”.
So ladies and genetleman, we are the experiment. And we have no idea what will happen.