What is climate change? The earth’s climate has always been changing all over its evolution. Indeed, the earth’s temperature went through icy or warm period. So, the climate change is a long modification of the climate over many millenniums. For examples 20 000 years ago all of Northern Europe was covered by a thick sleep of ice. In Europe it was 15 degrees colder than now but the average it was 5 degrees.

Today, computers can measure the climate’s variation, that’s to say observe currents, atmosphere, wind, clouds, temperature, greenhouse effects… Thanks to these calculations, scientists can compare the behave of the climate. Thus, regarding the actual tendencies, they conclude that temperature is increasing and will continue to increase over the next centuries. That’s why we can wonder why there is a climate change and for what reasons. •The causes of climate change [1]Natural causes or human activities? The climate change is basically due to a natural long-term cycle of warming. However, since the 19th century and the industrial revolution, humans activities have induced an acceleration of the global warming. Indeed, with the development of the polluting industries and transports, the global temperature has quickly speeded up for 150 years. In fact, the average temperature on earth has risen from (15) fifteen to (15.8) fifteen point eight Celsius degrees. The concentration of CO² in the atmosphere has increased too, owing to the demographic explosion and industrialization; indeed, now, we use more energy, and we burn more gases, more coal than two centuries ago. Thus, if we compare the growing of the population, the development of the polluting industries since nineteen hundred and the rise of the temperature, we can clearly see, that human activities and climate change are linked; even though the natural tendencies are also responsible but to a lesser extent. The greenhouse effect

Our planet is