Scientists trying to determine how the Earth might change as temperatures rise often look back in time to a period around 3.6 million years ago called the middle Pliocene, when concentrations of carbon dioxide ranged from about 380 to 450 parts per million. (Today they are nearing 400.)

[More]



Add to digg
Add to StumbleUpon
Add to Reddit
Add to Facebook
Add to del.icio.us
Email this Article





Source: Ice-Free Arctic in Pliocene, Last Time CO2 Levels above 400 PPM


David Cottle

UBB Owner & Administrator