Global warming

Throughout its long history, Earth has warmed and cooled team and again. Climate has changed When the planet received more or less sunlight due to subtle shifts in its orbit, the surface or the atmosphere changed, or When the Sun's energy varied. But in the past century, another force has started to Influence Earth's climate: humanity Previous versions of this article were published in 2007 and 2002. Archived versions are available as PDF files. (NASA astronaut photograph ISS022-E-6674. ) What is Global Warming? Global warming is the unusually rapid power increase in Earth's average surface temperature over the past century Primarily due to the greenhouse gases released by people burning fossil fuels. How Does Today's Warming Compare to Past Climate Change? Earth has experienced climate change in the past without help from humanity. But the current Climatic warming is occurring much more Rapidly than past warming events. Why Do Scientists Think Current Warming Is not Natural? In Earth's history before the Industrial Revolution, Earth's climate changed due to natural causes unrelated to human activity. These natural causes are still in play today, but Their Influence is too small or too slowly They Occur to explain the rapid warming seen in recent decades. How Much More Will Warm Earth? Models predict That the the world consumes ever more fossil fuel, greenhouse gas Concentrations will proceed to rise, and Earth's average surface temperature will rise with Them. Based on plausible emission scenarios, average surface temperatures Could rise between 2 ° C and 6 ° C by the end of the 21st century. Some of this warming will Occur even if future greenhouse gas emissions are Reduced, because the Earth system has not yet fully adjusted to environmental changes we have made Already. How Will Earth Respond to Warming Temperatures? The impact of global warming is far greater than just Increasing temperatures. Warming modifies