Word: co2
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...study just published in Science, there may not be any mystery after all. By looking at the chemistry of fossilized foraminifera - tiny sea creatures no bigger than a grain of sand - a team led by Aradhna Tripati, of University of the California, Los Angeles, has detected a significant CO2 bump during both warming episodes...
Some of the best evidence linking rising carbon dioxide levels to a warmer world comes from the coldest places on earth. Samples of ancient air extracted from deep inside the Antarctic and Greenland ice caps make it clear that CO2 is scarce in the atmosphere during ice ages and relatively abundant during warmer interglacial periods - like...
...relationship between CO2 and climate is clear going back about 800,000 years. Before that, however, it gets murkier. That's largely because ice and air that old haven't yet been found. So scientists rely instead on indirect measurements - and these have led to a climate mystery: some episodes of past warming, including a planetary heat wave about 15 million years ago and another about 3.5 million years ago, seem to have happened without a rise in CO2. No one quite understands why. Maybe other greenhouse gases were the cause - methane, for example. Or maybe...
...they're right, it could be pretty bad news, even for those who already worry about rising CO2. It's generally agreed that during the earlier warm period, known as the Miocene Climatic Optimum, which occurred 15 million years ago, the global temperature was high enough to make sea levels between 80 ft. and 130 ft. higher than they are today. According to the new study, CO2 levels in the atmosphere at that time hovered at from 390 to 430 parts per million (p.p.m.). Today's CO2 level: 387 p.p.m. and rising...
...course, an increase in CO2 (or any other heat-trapping greenhouse gas) can't lead to that kind of sea-level rise unless the CO2 level stays high for a while. The latest projections suggest a rise of 6 ft. at most by 2100, even if CO2 continues to increase at the current rate. But the new study implies that failing to tamp down emissions could eventually lead to a disaster worse than most climate Cassandras have dreamed of. (See pictures of the effects of global warming...