Changes in the climate are not new. In fact, changes in climate are as old as our planet. The overall tendency of the global temperature over the course of geological time shows that the climate has been rather hot, except for the 5 ice ages. The last one of which is the Quaternary Era, in which we are currently living.
However, the current changes in climate cannot be considered as ordinary. Because of its scale and rapidity, this warming of our climate can only be described as extraordinary in the history of our planet.
« Klima »
Le The word climate comes from the Greek "klima" meaning "inclination", refferring to the major role of the inclination of solar rays on the earth's surface. The etymology of the word reminds us that the average temperature of our planet is affected, at least partially, by the natural cycle of our king, the sun.However, the current rise in temperature is too great to be exclusively linked to solar activity..
The evolution of temperature and the concentration of CO2 since the year1000
The greenhouse effect
Our life style and daily consumption patterns emit large quantities of greenhouse gases (GHG). The worsening of this greenhouse effect plays an important role in climate change. Each one of us has to be aware that today we have to reduce our greenhouse gas emissions.
Causes of climate change
The current climate change is linked mostly to greenhouse gas emissions resulting from human activities. These emissions of anthropogenic origin are by themselves responsible for more than 3/4 of the carbon dioxide (CO2). The consumption of fossil fuels (energy production, fuel for vehicles, home heating, industry) is by far the most incriminating factor. But we should not forget that changes in land use, including deforestation, occupy second place in term of responsibility for the worldwide increase in greenhouse gas emissions (17% of global emissions).
The effects of climate change: the unequal distribution of the impact
Global warming introduces an additional factor of inequality and disparity between the different geographical regions of the planet. The populations of the world's poorest countries are more vulnerable when faced with the effects of climate change even though they are less responsible for it. The developing countries are not able to protect themselves against the impact of this phenomenon nor adjust to it. Climate change increases the precarious situation of the poorest populations (food security, access to health care, water and energy, housing...), widening even further the socio-economic divide between the North and the South.
Because of their location, their low incomes, the insufficiency of their resources and institutional capacities, and because they mostly count on climate dependent sectors like agriculture, populations of the poorest countries are the first victims of current and future climatic changes.
To go one step further
> Lire le livre "L'odyssée du climat", Gaël Derive, Editions Terre vivante, 2008.
> Lire le livre "Le climat à découvert", ouvrage collectif, CNRS éditions, 2011.