Climatologists usually use the term "climate change" to talk about the probable consequences of the enhanced greenhouse effect.
Our planet has adapted to larger variations in temperature and sea levels in the past. This time, however, people may suffer the most. As humanity has developed, it has cleared farmland and built roads, railways and homes with the belief that the water system would remain stable. If sea levels rise and the climate changes, the very foundation of our society could be destabilized.
Without giving in to catastrophic predictions, let's look at some of the probable consequences of climate change.

More severe storms
It is possible that warming will lead to more numerous and violent storms. Hurricanes begin forming over oceans when the temperature exceeds 27°C. A warmer world would probably have warmer oceans. In general, storms are often the result of significant temperature differences.

Higher sea levels

Between 1990 and 2100, the IPCC expects a rise of 18 to 59 cm in the average sea level due in part to melting polar ice and especially to thermal expansion of sea water. Half of the world's population lives in coastal areas. Residents will have to abandon certain islands and find ways to hold back rising water in deltas and low-lying coastal regions.

Impact on ecosystems and agriculture

Climate change could considerably modify rain patterns, leading to drought and flooding unevenly across the planet. Regions with favorable temperatures and rainfall for different types of plants could move, but forests, crops and brush may not be able to migrate fast enough. Not to mention the potential consequences of extreme weathe (drought increases the risk of fire, low winter temperatures favor the development of insects and pathogenic organisms, certain seeds need a period of freezing to germinate, etc.). Forests also store massive amounts of carbon, which is a major contributor to the greenhouse effect. If forests disappear, this carbon will be released.

Risks for human health
Areas where tropical diseases tend to develop could expand towards the north and south, leading to the proliferation of infectious illnesses and certain types of mosquitoes that carry such scourges as malaria, Nile Valley fever, dengue and yellow fever. Populations in regions spared until now would be even more sensitive to these diseases.

What would be the consequences for a country like France?
In the next century, if greenhouse gas emissions continue to rise at their current pace, the temperature in France should be 1 to 2°C higher in winter and more than 2°C higher in summer and fall. The potential consequences, according to the inter-ministerial mission on the greenhouse effect, are as follows:
- There would be less rain in the summer and more in the winter,
- The snow cover above 1,500 meters would last for a much shorter period,
- The sea would infiltrate Camargue and the Languedoc lagoons,
- Beech groves in northern France and pine forests in the Landes region would be threatened by drought,
- New cases of malaria could appear with the return of disease-bearing mosquitoes.

What would be the economic impact?
The IPCC puts the cost of damage related to a 2.5°C increase in temperature at between 1.5% and 2% of global GDP. Industrialized countries would see a smaller decline (1% to 1.5%) than the developing economies (more than 2%).