10 results found for: “Climate_Change”.

Main result

Climate change

Climate change is the climate of Earth changing. The Earth's climate has been much hotter and colder than it is today. Climate change this century and last century is sometimes called global warming, because the average temperature on the surface has risen. The last decade (2011–2020) was the warmest on record, and each of the last four decades has been warmer than any previous decade since 1850. The climate is now changing much faster than it has in the recent past. This is because people are putting more greenhouse gases in Earth's atmosphere, and they block some heat from escaping from the Earth into space. When people talk about climate change they are usually talking about the problem of human-caused global warming, which is happening now (see global warming for more details). But the climate of the Earth has changed over not just thousands of years, but tens or hundreds of millions of years. Sometimes, before there were people, the Earth's climate was much hotter than it is today. For example about 60 million years ago there were a lot of volcanoes, which burnt a lot of underground organic matter (squashed and fossilized dead plants and animals became coal, gas and oil). A lot of carbon dioxide and methane went up in the air. At times in the past, the temperature was much cooler, with the last glaciation ending about ten thousand years ago. Ice Ages are times when the Earth got colder, and more ice froze at the North and South Poles. Sometimes even the whole Earth has been covered in ice, and was much colder than today. There is no one reason why there are Ice Ages. Changes in the Earth's orbit around the Sun, and the Sun getting brighter or dimmer are events which do happen. Also how much the Earth is tilted compared to the Sun might make a difference. Another source of change is the activities of living things (see Great Oxygenation Event and Huronian glaciation).