What is happening to weather and climate nowadays?
Our weather is always changing and now scientists are discovering that our climate does not stay the same either. Climate, the average weather over a period of many years, differs in regions of the world that receive different amounts of sunlight and have different geographic factors, such as proximity to oceans and altitude.
Climates will change if the factors that influence them fluctuate (êîëåáàòüñÿ). The heat that enters into the Earth system comes from the Sun. Sunlight travels through space and our atmosphere, heating up the land surface and the oceans. The warmed Earth then releases heat back into the atmosphere. However, the amount of sunlight let into the system is not always the same. Changes in Earth’s orbit over thousands of years and changes in the Sun’s intensity affect the amount of solar energy that reaches the Earth.
Heat exits the Earth system as the Earth’s surface, warmed by solar energy, radiates heat away. However, certain gases in our atmosphere, called greenhouse gases, allow the lower atmosphere to absorb the heat radiated from the Earth’s surface, trapping heat within the Earth system. Greenhouse gases are an important part of our atmosphere because they keep Earth from becoming an icy sphere with surface temperatures of about0°F. However, over the past century or so the amounts of greenhouse gases within our atmosphere have been increasing rapidly, mainly due to the burning of fossil fuels, which releases carbon dioxide into the atmosphere. Consequently, in the past one hundred years global temperatures have been increasing more rapidly than the historic record shows. Scientists believe this accelerated heating of the atmosphere is because increasing amounts of these greenhouse gases trap more and more heat.
The reason studying climate and a changing climate is important, is that will affect people around the world. Rising global temperatures are expected to raise sea levels, and change precipitation and other local climate conditions. Changing regional climate could alter forests, crop yields, and water supplies. It could also affect human health, animals, and many types of ecosystems. Deserts may expand into existing rangelands, and features of some of our National Parks and National Forests may be permanently altered.
Date: 2015-01-29; view: 1664