Plants that thrive on a warmer Earth can produce nitrous oxide from the nitrogen in the air, which has 310 times the greenhouse effect of CO2. As global warming kicks in the same feedback could be initiated.
The last ice age may have ended partly because of the release of vast quantities of laughing gas, or nitrous oxide. A similar release could be on the cards later this century, although we cannot predict how much Earth will warm as a result.
Europe warmed by 5 °C about 14,500 years ago, towards the end of the last ice age, and ice cores show that this triggered a pulse of nitrous oxide. This sped up the warming process, as the gas has 310 times the warming potential of carbon dioxide.
According to Mirjam Pfeifferof the Swiss Federal Institute of Technology in Lausanne and her colleagues, the nitrous oxide came from the plants that prospered as the area began to warm.
"If we have climate change proceeding very quickly, the huge amounts of nitrogen stored in our ecosystem may be released as nitrous oxide," says Klaus Butterbach-Bahl of the Karlsruhe Institute of Technology in Germany.