How Much Does Global Warming Affect Agriculture?


Develop contingency measures to mitigate warming The average temperature of earth rose 0.74 degrees Celsius in the past century, but it could rise another 1.8 to 4 degrees in the next century, according to the United Nations Intergovernmental Panel on Climate Change (IPCC) forecast in 2007. And the Central Weather Bureau statistics in 2009 showed that the average temperature in Taiwan rose 0.8 degrees Celsius in the past 100 years but rainfall decreased drastically with more single-day rainfall and more days of heavy rains. Because of higher temperatures, sea levels in the Kaohsiung coastal area rose 6.79 mm every year in the past 10 years, much higher than the average 1.8 mm increase of sea levels around Taiwan. With an annual land subsidence rate of 7.89 mm, land in southwest Taiwan is slowly disappearing. Academia Sinica Vice President Chao-Han Liu mentioned these astonishing numbers when addressing the opening of the Policy Conference on Adjusting Agriculture in Response to Climate Changes in June 2010.

Metropolitan area temperatures rose 1.4 degrees Celsius in the past century, with the average lowest temperature rising 2.1 degrees. In the evening, which should be cool, temperatures are even higher than in the daytime because of the warming effect. The incidence of heat waves and their duration increased significantly in the past 50 years, with temperatures in northern Taiwan changing more drastically.

Climate changes have warmed Taiwan and changed rainfall patterns, thus affecting agricultural production. For instance, rising sea levels will flood or cause high salinity of coastal farmland, and rainfall changes will lead to drought or affect the supply of water resources. In the next 30-60 years the average evaporation in the rice growing season will increase 2.1% and 6.8%, according to research. In other words, crops will consume more and more water resources. Global warming has risen sea levels and seriously affected the agricultural production base in southwest Taiwan. The affected agricltaml areas are estimated at 1,246 square kilometers, almost equal to the 1,290.84-square kilometer whale land area of Yunlin County, an important agricultural pmduetion area. In addition to slow down global warming, we have to formulate contingency measures in response to climate changes.

Therefore, the experts made several proposals when discussing the subject of “strategic adjustment of Taiwan’s agricultural resources and ecological environment.” The first is strategic adjustment of water resources which are closely related to agricultural production. When there were abundant water resources, convenient and free of charge water supply provided by Taiwan’s good irrigation and water conservancy facilities often led to waste of water resources. Now the experts have reminded us repeatedly to face the problem of agricultural water resource shortage. Such problems as dry season caused by climate changes or agricultural water shortage in the time of drought, forced diversion of water used by industry or families, as well as efficient utilization of irrigation and water supply facilities and water resources have to be planned in advance. Otherwise, farmers will become “unemployed” when a lot of farmland is forced to lie fallow due to the water shortage. The Policy Conference on Adjusting Agriculture concluded that in addition to establishing the “agricultural water distributing operation fund,” increasing the efficiency of diverting water for industrial or family use and protecting farmers’ rights and interests, farmers should also take into consideration the production mode of conserving energy and reducing emissions.

Irrigation systems and drought contingency measures should be established, and to review the water and water storage facilities While the agricultural water resource system should have contingency measures against drought, farmers should also review water facilities in their farmland, ranches or fish farms. For example, paddy fields used to be flooded with water as well as vegetable gardens and orchards which require irrigation should plan for water conservation. Such measures being promoted by the government as alternate irrigation, spraying dry land and reusing recycled fish farm water are the new policy measures farmers should consider to adopt.

Fishermen may develop desalination techniques learning from countries with large deserts and establish in the future a coordinated supply system for desalinated sea water. They should develop sea water aquaculture for food production in response to water resource deterioration caused by climate changes, while promoting aquaculture using recycled freshwater to decrease reliance on freshwater resources. In addition, fish farms not suitable for aquaculture should be turned into wetland, ecological education grounds, eco ponds or flood detention basins.

The livestock industry can improve ventilation, temperature control facilities as well as water supply in its animal or poultry house, reduce water consumption and set up a purification tank for liquid waste or increase reusing of recycled waste water.

Adjusting agriculture in response to climate changes for us is to understand the problems agriculture may encounter in the future and completely prepare in advance to minimize possible damages and prevent farmers from becoming climate refugees.