Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Climate change may be due to natural internal processes or external forces, or to persistent anthropogenic changes in the composition of the atmosphere or in land use. Climate Change is define as: "a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods".
The discovery by scientists for more than 100 years ago shows that the increased in atmospheric carbon dioxide heats up the entire planet. The scientist is the French researcher, Jean Baptiste Fourier and the Swedish scientist Svante Arrhenius. Their discovery came to be known as the greenhouse effect, which include natural factors and human activities that contribute to the increase of carbon dioxide in the air.
Without the so-called greenhouse gases, including carbon dioxide, methane, nitrous oxide, and water vapour, Earth would be too cold to inhabit. These gases in Earth's atmosphere absorb and emit heat energy, creating the greenhouse effect that keeps our planet's temperature liveable. Water vapour is the most important greenhouse gas on the planet, accounting for about 60% of the current greenhouse effect. Even ozone helps trap some of the heat that makes life on the Earth possible.
Since the industrial revolution, people have burned vast amounts of coal, petroleum, and other fossil fuels to create heat and power. This releases carbon dioxide, the most plentiful human-produced greenhouse gas, into the atmosphere. The result: more heat is trapped in Earth's atmosphere instead of radiating out into space.