- A new historical record of carbon dioxide levels suggests current political targets on climate may be “playing with fire”, scientists say.
Data came from samples brought up by the drilling ship Joides Resolution
Researchers used ocean sediments to plot CO2 levels back 20 million years.
Levels similar to those now commonly regarded as adequate to tackle climate change were associated with sea levels 25-40m (80-130 ft) higher than today.
Scientists write in the journal Science that this extends knowledge of the link between CO2 and climate back in time.
The last 800,000 years have been mapped relatively well from ice cores drilled in Antarctica, where historical temperatures and atmospheric content have left a series of chemical clues in the layers of ice.
But looking back further has been more problematic; and the new record contains much more precise estimates of historical records than have been available before for the 20 million year timeframe.
Sustained levels
Full storey: news.bbc.co.uk
