Human activities contribute to
climate change by causing changes in Earth’s atmosphere in the amounts of
greenhouse gases, aerosols (small particles), and cloudiness. The largest known
contribution comes from the burning of fossil fuels, which releases carbon
dioxide gas into the atmosphere. These fossil fuels are used in transportation,
building heating and cooling and the manufacture of cement and other goods. Deforestation
also releases carbon dioxide, and reduces its uptake by plants. Carbon dioxide
is also released in natural processes such as the decay of plant matter.
Another greenhouse gas is ozone, this is continually produced and destroyed in the atmosphere by chemical reactions. In the troposphere, human activities have increased ozone through the release of gases such as carbon monoxide, hydrocarbons and nitrogen oxide, which chemically react to produce ozone. Halocarbons released by human activities destroy ozone in the stratosphere ad have caused the ozone hole over Antarctica meaning that the Antarctic area is more vulnerable to UV rays, thus making the temperature warmer. Since the start of the industrial era (about 1750), the overall effect of human activities on climate has been a warming influence. The human impact on climate during this era greatly exceeds that due to known changes in natural processes, such as solar changes and volcanic eruptions. |
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