Geography of New Zealand are generated by greenhouse gases, mainly methane and nitrous oxide, which come from farming and agriculture. Organisms that grow inside of grazing animals' stomachs turn New Zealand's grass into methane. The increase of carbon dioxide in the air helps the plants to grow faster, but the long-term effects of climate change threaten farmers with the likelihood of more frequent and severe floods and droughts. Growers of kiwifruit, a major export in the horticulture industry of New Zealand, have experienced difficulties as a result of climate change. The recent warm winters are not providing the adequate cool temperatures needed for the
Nitrous oxide and thus creates foam. Used in this way, it produces whipped cream four times the volume of the liquid, whereas whipping air into cream only produces twice the volume. If air were used as a propellant, oxygen would accelerate rancidification of the butterfat, but nitrous oxide inhibits such degradation. Carbon dioxide cannot be used for whipped cream because it is acidic in water, which would curdle the cream and give it a seltzer-like "sparkling" sensation. The whipped cream produced with nitrous oxide is unstable, however, and will return to a more liquid state within half an hour to one hour.