The greenhouse gases emitted, largely due to the human activity of the past two centuries (fueled by burning fossil fuels that add great quantities of carbon dioxide in the atmosphere) are the main responsible for the increase in temperature. These gases are released notably by the use of hydrocarbons (gas, oil, coal), but also methane (used for refrigeration and air conditioning). It is also exacerbated by massive deforestation. The likely results of this phenomenon are multiple and very important: higher maximum and higher minimum temperatures, more intense precipitation events, increase of droughts all over the world, increase of tropical cyclone activity, alteration of the distribution of world’s water resources, changes in the extent of Arctic sea ice and permafrost and finally the sea-level rise which is one of the most important and threatens a lot of coastal cities, wetlands, low lying islands and even countries (Netherlands). Responses to rising temperatures should initiate an effort at global and individual level. Since early 2000’s governments all over the world took many steps and including the issue of new alternative energies (wind, photovoltaic panels ...), stopping deforestations, favor green products, but everyday actions can help lower emissions of greenhouse gases and thus fight against global warming.