Jean-Louis Etienne
 
 
 
Jean-Louis Etienne - Alone on Ice pack
How man copes with the cold
 
Communications - Safety - Emergency assistance
 
Jean-Louis Etienne - Atmosphere & weather
The earth’s atmosphere  
 
Weather forecasting and modeling  
 
The climate and the north pole  
 
The solar energy balance  
 
The greenhouse effect  
 
Jean-Louis Etienne - Arctic ice
The ice pack: frozen saltwater  
 
Ice pack observation satellites  
 
Icebergs : frozen seawater  
 
The arctic ice: climate archives  
 
Ice ages and landscapes  
 
Jean-Louis Etienne - The ocean and marine life
The Arctic Ocean and the ocean currents  
 
Genesis of the arctic ocean  
 
Arctic plankton  
 
Oceanic biodiversity and the food chain  
 
Whales and other cetaceans  
 
Seals and walruses  
 
Jean-Louis Etienne - Life on land
Arctic flora  
 
Arctic fauna  
 
Polar bears  
 
Birds of the arctic  
 
Evolution of species and climate  
 
Jean-Louis Etienne - History and geography
Geography of the Arctic regions  
 
Geographic North Pole and magnetic North Pole  
 
Who owns the arctic ?  
 
Exploring the deep north  
 
The Inuit people  
 
The other peoples of the deep North  
 
The Arctic today  
 
Jean-Louis Etienne - Man's impact
Man and arctic biodiversity  
 
Pollution in the arctic  
 
Climate warming: the natural cycles  
 
The increase in the greenhouse effect  
 
The impact of global warming  
 
 
 
Man's impact
Climate warming: the natural cycles
 
 

A climate that might seem stable…
The Earth’s climate varies, and this is a natural phenomenon, but it changes so slowly that human beings with their short life-span do not notice it. The greatest variations can only be measured in terms of tens of millions of years, which is the time-scale of continental drift. Other changes, those due to fluctuations in the Earth’s orbit, are measured in terms of tens of thousands of years, and the most rapid changes would require data over centuries or at least decades.

Climate during the early ages of the Earth’s existence
We know very little about the climate during the Earth’s first few billion years, but scientists think the Earth was warmer and the Sun less powerful than it is today. Subsequently, even if the overall climate was warmer, there were at least four periods of extreme cold between 1.7 billion years ago and 600 million years ago.

Palm trees once grew at the North Pole
During the Secondary era, when dinosaurs roamed our planet, the temperature at the poles sometimes reached 20°C. There was no ice cap, and the position of the continents at that stage meant that the ocean currents could circulate more freely, so the heat exchanges were greater than they are today. Then 65 million years ago, the Earth’s climate became colder, and over the last 2-3 million years ice ages and warmer periods have alternated.

Understanding the past in order to predict the future
How can we learn more about the long history of our planet’s climate? By analysing the ice layers at the poles, by studying sediments and rocks, by examining fossils, by observing the growth of corals, etc.
And a better understanding of how climate changes were caused in the past is a vital step towards predicting how that climate may change in future.

 
Jean-Louis Etienne
Jean-Louis Etienne
 
 
 
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