climate and geopolitical stakes of COP21

It is a conference presented by Hervé Le Treut, who has several functions : he is the director of the Institut Pierre Simon Laplace, a member of the Scientific Academy, and he is climatologist too.
This presentation was interesting within the framework of the conference because the problematic of climate change is totally contemporary : the different effects of economic activities in our societies are the source of a lot of problems, it is consequently important to talk about it and to expose the different aspects of those stakes.
The way in which the climate has been modified had not been considered, and this influences the type of solution that we will seek.
The climatic system is multiple: we are talking about the atmosphere which is a quick system, about the ocean which is the metronome of other systems…
The climate in which our civilisations developed themselves corresponds to a very particular situation: we have known 10 000 years of ‘’nearly stability’’ and some decades of change. The context: The CO2 emissions linked to the hydrocarbon’s combustion do not decrease. This phenomenon started during the 1950’s: the first problems arose during the 1970’s and became mondial in 1992 in Rio (during the Earth Summit). Today, we still are in a great increasing dynamic of the greenhouse gas emissions.
The objective of the COP21 will be to find solutions in order to force things and to think about a stabilization of the global warming into 2° until the end of the century.
There is a very strong pressure because the CO2 remains in the atmosphere a hundred years. As a result, we are getting closer to a saturation, and one day we won’t be able to use CO2 anymore. The decreasing of this gas emissions and our will to diminish the greenhouse gas of 40-60% until 2050 are really necessary.
What are the different types of action considered by the COP21? Is that enough? We need to decrease the use of hydrocarbons and to invent new technologies that will allow us to seek (or to recover) some CO2 in the atmosphere.
The global warming is stronger at the poles. The first observations of the global warming are made today, notably through different changes: the increase of the sea level, the melting of the Arctic glaciers…
We also need to combine the risks linked to the global warming with social and sanitary risks.