Oxygen link to climate change
New research suggests oxygen too plays a key role in climate change
OXYGEN IS not a greenhouse gas and that's why it has not been studied in the context of climate change. The proportion of atmospheric oxygen has, however, varied between 10 per cent and 35 per cent over the past 541 million years.
Now, Christopher Poulsen and colleagues at the University of Michigan have developed a model to show how these fluctuations impacted climate. In periods when oxygen levels declined, the resulting drop in atmospheric density led to increased surface evaporation, which in turn led to precipitation increases and warmer temperatures. While not as critical to climate as heattrapping carbon dioxide gas, oxygen plays a key role. Currently, oxygen comprises about 21 per cent of Earth's atmosphere by volume. Science, June 11