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 careful heating of ammonium nitrate at about 250 C, which decomposes into nitrous oxide and water vapour. The addition of various phosphate salts favours formation of a purer gas at slightly lower temperatures. This reaction may be difficult to control, resulting in detonation. The decomposition of ammonium nitrate is also a common laboratory method for preparing the gas. Equivalently, it can be obtained by heating a mixture of sodium nitrate and ammonium sulfate: Another method involves the reaction of urea, nitric acid, and sulfuric acid: Direct oxidation of ammonia with a manganese dioxide-bismuth oxide catalyst has been reported: cf. Ostwald