An Effect of Climate Change
Climate change poses a major threat to world agriculture. The climate's NORMAL patterns are vitally connected to where, how, and when food is grown. But with climate change, many farmers can't keep up with the constantly changing climate. For example, the National Climate Assessment in the United States of America has recently concluded that the U.S. Southwest can expect less precipitation, hotter temperatures, and drier soils in the future, meaning that by 2060, there could be as much as a 35 percent increase in water demand. Along with that comes a 25 to 50 percent increased risk of water shortage. Part of this water demand is for agricultural usage. The necessary water for growing crops is going away because of climate change, and this could have a drastic effect on world hunger.
Unpredictable extreme weather also has an effect on the agricultural growth of certain regions. As I previously stated, normal climate patterns are connected to food growth. While extreme weather has been on earth forever, it is more intense than before, and that is caused by climate change.
Climate change also causes the air to be warmer. This may be good for some plants, but it causes pests to have more breeding and growing cycles, which is harmful to plants. In addition, certain research has shown that climate change may alter the development of diseases that are harmful to plant growth.
Climate change also creates a longer growing season, but that growing season is accompanied by frost. This kills the small growing plants which in turn destroys productivity. And while the growing season is longer, the intensity of the sun does not change. And in fact, the sun is actually cooling (this also refutes climate deniers' main arguments). This has nothing to do with climate change, but it just shows that the plants will not have increased productivity, but, because of the frost, decreased productivity.
Swings in weather also affect agriculture productivity.