What is Global Warming?
What is global warming? Here we discuss the science of global warming, its causes and effects, and why it is one of humanity's biggest challenges. Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. IPCC Climate Change 2007 Report Global warming is quite a recent phenomenon that came to international prominence only by the end of the 20th century. But man-made pollution was known to affect the climate system of the planet as long ago as the middle – end of the 19th century. It was first suggested in 1863 that changes in the composition of the atmosphere due to pollution could lead to climate change. In 1896 the Swedish scientist Svante Arrhenius made first actual calculations of the effect of greenhouse warming in which he estimated that a doubling of carbon dioxide [in the atmosphere] would increase the global avera...