What is the impact of climate change on food security?

Climate change or the spread of pests and diseases threaten food security.

It is found that climate change will increase the risk of pest transmission in agricultural and forestry ecosystems, especially in the cold Arctic, northern, temperate and subtropical regions. In addition, some pests, such as beet armyworm, are also spreading due to climate warming. Other species, such as desert locust (the most destructive migratory pest in the world), are expected to change their migration routes and geographical distribution due to climate change.

Studies have pointed out that half of all emerging plant diseases are spread through global travel and trade. According to statistics, in the past ten years, global travel and trade volume have increased dramatically. Weather is the second major factor affecting the spread of plant diseases.

Five factors affecting climate

1, latitude position. Usually the equatorial region has the most precipitation, and the precipitation near the poles is the least. Near the Tropic of Cancer, there is more precipitation on the east coast of the mainland and less precipitation on the west coast. Because the earth is a big sphere, the sun shines at different angles at different latitudes. Some places are direct, some places are oblique, and some places have not been exposed to the sun all day or for months. Generally, the lower the latitude, the higher the temperature; The higher the latitude, the lower the temperature.

2. Atmospheric circulation. It is the main factor that forms various climate types and weather changes. The manifestations of atmospheric circulation include planetary wind system, monsoon circulation, land-sea wind and valley wind. What people usually call atmospheric circulation mainly refers to planetary wind system. Under the control of different pressure belts and wind belts, the climate characteristics, especially the changes of precipitation, are significantly different. In addition, the wind belt and pressure belt move with the seasons, thus forming various climate types.

3. Land and sea distribution. The distribution of land and sea changes the zonal distribution of temperature and precipitation. Due to the different physical properties of the ocean and the land, under the strong sunlight, the ocean heats up slowly and the land heats up quickly; After the sun weakened, the ocean cooled slowly and the land cooled rapidly. In temperate regions, there is more precipitation in coastal areas and less precipitation in inland areas. At the same latitude, controlled by the same pressure belt or wind belt, the climate characteristics are different because of the different land and sea positions.

4. Terrain. Terrain is a non-zonal factor, and different landforms have different effects on climate. In the same latitude zone, the higher the terrain, the lower the temperature, and the precipitation increases with the height within a certain height range. Usually, there is more precipitation on windward slopes and less precipitation on leeward slopes in mountainous areas.

5. Ocean current factor. Ocean currents also have a certain influence on the climate along the coast of the continent through which they flow. Warm current plays a role in warming and humidifying the climate in coastal areas. For example, the formation of maritime climate in western Europe directly benefits from the warm and humid North Atlantic ocean current. The cold current plays a role in cooling and dehumidifying the climate in coastal areas. For example, the cold current on the west coast of the mainland (southern hemisphere) played a certain role in the formation of desert environment on the west coast of Australia and the Pacific coast of Peru.

Light. Com-FAO: Climate change or the spread of pests and diseases threaten food security.