Climate Change Research Shows Rising Levels of CO2
Byline: John von Radowitz
Carbon dioxide in the atmosphere is at its highest level for more than two million years, scientists revealed yesterday.
The spike in CO2 levels coincided with the start of the industrial age, according to the US study, which suggested Earth was going through a period unique in its history.
It means scientists will have to search back further in time to find conditions comparable with those driving modern-day climate change.
Studying previous climate change trends can help experts understand what is happening today - and what is likely to occur in the future.
Scientists had thought that decreasing levels of carbon dioxide in the atmosphere caused a major change in Earth's glacial cycle some time between 1.2 million and 500,000 years ago.
Previously, the planet underwent an ice age roughly every 41,000 years.
After the transition, the cycles of freezing and warming grew to 100,000 years. At the same time, ice sheets covered more of the Earth's surface than they had for several million years - a change too great to be explained by orbital variation alone.
One likely reason for the change was believed to be lowering levels of carbon dioxide in the atmosphere. …