Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-twentieth century, and its projected continuation.

The average global air temperature near the Earth's surface increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the hundred years ending in 2005. The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic (man-made) greenhouse gas concentrations" via an enhanced greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward

These basic conclusions have been endorsed by at least thirty scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. While individual scientists have voiced disagreement with some findings of the IPCC, the overwhelming majority of scientists working on climate change agree with the IPCC's main conclusions.

The Oceans are also warming @ 0.05^oF each year. Rising CO₂ in the atmosphere, large scale accidental and industrial discharges of petroleum products are an important cause of heat in ocean, devastating many aquatic organisms.

Due to Global warming, faster melting of Glaciers form Himalayas, Alps & other mountains and also arctic ice is increasing the sea level and in last 100 years it has risen by 1.8 mm annually and is likely to increase further by more than a 1/2 meter by the end of his century.