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Why do small changes in Earth's temperature have a big impact?


Heat, Insect Life Cycles and Animals
Warmer temperatures could mean longer, more frequent waves of mosquito infestations.
Warmer temperatures could mean longer, more frequent waves of mosquito infestations.
iStockphoto/Thinkstock

Temperature plays an important part in the life cycle of insects. Many insects die during the colder winter months. But if temperatures should increase by just a couple of degrees, a number -- perhaps a significant number -- of these insects won't die. This could lead to a jump in insect population. Insects may also breed earlier in the year, which is bad news for crops. The growing season is when plants tend to be the most vulnerable -- if insects breed earlier they may wreak havoc during the crop growing season.

Higher temperatures tend to increase the speed of an insect's life cycle. That means insects will mature, mate and reproduce in a shorter span of time than normal. It also means there will be less time between one generation of insects and the next. Before long, you have a potential plague of pests infesting the area.

Another charming characteristic of insects -- they can carry diseases. Mosquitoes, for example, are known for being carriers of various illnesses, such as malaria. As temperatures increase, these mosquitoes will be active through more of the year and will be able to reproduce in greater numbers. As a result, we can expect to see disease rates rise, particularly in developing countries. The cost of managing illnesses and combating the mosquito populations could be enormous.

Many animals are able to cope with a slight increase in temperatures, but some live in regions that are more vulnerable to temperature changes. A good example is the polar bear. As temperatures increase, polar bears lose large portions of their habitat. Ice melts, and polar bears have fewer places where they can go hunting. Other species may experience similar problems, facing starvation as native plants struggle to survive in a warmer environment.

Ultimately, warmer temperatures can lead to a decrease in biodiversity in certain areas. Why is this important? Biodiversity helps protect the life of a region. As diversity decreases, the remaining populations become more vulnerable to catastrophic events like famine and disease. It's possible that a particularly rough year could wipe out a significant percentage of the organisms in a region.

Let's take a look at how an increase of just a couple of degrees could affect weather patterns and life in the sea.