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 that cuts off their supply of fresh air. Long-term exposure to nitrous oxide may cause vitamin B deficiency. It inactivates the cobalamin form of vitamin B by oxidation. Symptoms of vitamin B deficiency, including sensory neuropathy, myelopathy, and encephalopathy, may occur within days or weeks of exposure to nitrous oxide anaesthesia in people with subclinical vitamin B deficiency. Symptoms are treated with high doses of vitamin B, but recovery can be slow and incomplete. People with normal vitamin B levels have stores to make the effects of nitrous oxide insignificant, unless exposure is repeated and prolonged (nitrous oxide abuse). Vitamin