What is the name of the phenomenon which is increasing earth's atmospheric temperature and causing widespread environmental changes?

Global warming caused by greenhouse gases is a phenomenon that environmentalists warn will severely challenge human existence. There have historically been changes in climate when there has been less or more sunlight due to slight differences in the Earth's axis. However, what is referred to as global warming is a rapid increase in Earth’s average surface temperature that can't be explained by this factor.

Over the past century humans have burned fossil fuels to a dangerous extent, not just for warming themselves, but for driving machinery. The greenhouse gases released has led to this rapid increase in the Earth's temperature. It is not just the 0.6 degrees increase, but the rate of increase that is of concern. This has doubled since 1905.

This is the trapping of the sun's warmth in a planet's lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.
The existence of the greenhouse effect was argued for by Joseph Fourier in 1824. The argument and the evidence were further strengthened by Claude Pouillet in 1827 and 1838 and reasoned from experimental observations by John Tyndall in 1859, who measured the radiative properties of specific greenhouse gases.

The effect was more fully quantified by Svante Arrhenius in 1896, who made the first quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide. However, the term "greenhouse" was not used to refer to this effect by any of these scientists; the term was first used in this way by Nils Gustaf Ekholm.

Greenhouse effect-the gases, which have a tendency of absorbing the suns heat, are called greenhouse gases, for example carbon dioxide (co2). The burning of fossil fuels like coal and petroleum releases a large amount of these gases into the atmosphere. Thus, the amount of heat absorbed by the atmosphere increases. This causes the global atmospheric temperature to rise.

Rising temperatures can cause the polar ice to melt and eventually raise the sea levels across the world. As the water levels rise, low-lying areas will get submerged.