The gradual warming of the Earth's surface will have impacts on water availability, ecosystems, food, coastal belts, and health.
The greenhouse effect is the process whereby certain gases, which are components of the planetary atmosphere, retain part of the energy released by the soil after the latter has been heated by solar radiation. These gases are called Greenhouse Gases (GHG).
There are many kinds of GHG besides CO2, such as methane (CH4), laughing gas (N2O), fluorinated synthetic industrial gases (CFC, HFC, PFC, SF6…) and ozone itself (O3). Although many of these gases are much more effective than CO2 in absorbing thermal radiation, carbon dioxide is the main culprit for global warming, as it is more abundant.
Greenhouse gases are necessary to maintain the Earth’s temperature at inhabitable levels (without them, the planet’s atmosphere would be about 33° colder…), but their excessive concentration causes a temperature increase on the planet which can affect life as we know it.
Every year, human activities produce more than 26,000 million tonnes of CO2, the most important greenhouse gas (GHG). This gas remains in the atmosphere for about a century before being absorbed by the oceans and terrestrial ecosystems. Given the long atmospheric life of this particular gas and the increase in human-generated CO2 emissions, the last two centuries have seen a gradual increase in CO2 concentration levels, causing a gradual heating of the Earth’s surface: climate change.