climatic change: climate and greenhouse effect

B. An alarming report > The global warming

The Warming up waited at the end of the 21st century

The summaries weather report confirms the rises of temperature bound to the emissions of gas to greenhouse effect in relation to the temperatures measured since 1861...

> Middle rise to the surface of the globe of 0,7°C since the beginning of the XXe century, but not non-stop. Since 1976, the rise accelerated, reaching 0,18°C per decade. The period 1997-2006 is marked by a middle rise of 0,53°C in the northern hemisphere and 0,27°C in the southern hemisphere, always in relation to the normal calculated for 1961-1990 (OMM, 12/2006).
> 11 of the last 12 years (1995-2006) were the hottest years ever recorded since 1850. Thus, the year 2005 is closely the hottest, consistent by 1998. The year 2005 is also the most expensive as regards to the meteorological natural disasters with more of 200 billions of dollars of damages.
> The year 2002 was the second year hottest after 1998 and 2005, since 1861.
> The year 2003 was the third year hottest since 1861.
> September 2005 was the hottest month ever recorded on the planet. While the fall 2006 beat many records of heats in Europe.
> The temperature of the tropical waters increased 1,2°C during the XX century (against 0,5°C on average for the oceans), dragging a scalding of the reefs coralliens appeared in 1997. In 1998, the warming up prolonged of water destroyed the half of the coral reefs of the ocean Indian. Besides, the temperature in the tropical zones of the five oceanic basins, where form themselves the cyclones, increased 0,5 Celsius degree of 1970 to 2004, however powerful cyclones appeared in the Atlantic North in 2005 (Katrina, Rita, Wilma), while they were more numerous in the other left of the world.
> The temperature in the Alps to 1800 m during the winter increased 1 to 3 degrees in the 40 years most recent (Weather report-France, 02/2005)

These phenomena and climatic anomalies intensify, some data:

On average, 200 millions of people are touched every year by the natural disasters and about 70 000 perish.
> The middle level of the seas rose of 12 cm since 1880 (5 cm due to the thermal dilation and 7 cm to the melting of the glaciers). Consequences: the disappearance of 100 km² of marshes in the delta of Mississippi, every year. And since 1990, the level of the seas increases 3 mm per year against 2 mm in the middle of the XXth century.
"In the biggest part of Alaska, the pergélisol In the Arctic regions, frozen soil permanently. won 1,6°C since the beginning of the years 1980 and until 3,3°C in some zones. Consequence: of the holes, named thermokarst (definition?), do appear suddenly.
"End December 1999, two successive storms crossed a part of Europe generating winds passing the 140 km/h on the half of France.
"August 2003, a heatwave without precedent touches Europe and mainly the damaged France with 15 000 deaths.
"2000, big precipitations and floodings in numerous regions of the globe: Italy, Switzerland and England of the months of October to December, Indochina with the rises in the water level of the most important Mekong in forty years, in Nagoya, to Japan, the rains of September, reached a level ever recorded since 1891, Texas recorded during the summer, 66 days without rain, of the seen ever since the observations of 1898
"Since the end of the years 1960, the world snowy cover decreased of about 10 to 15%. The wintry waves of cold weather in a big northern half of the northern hemisphere last two weeks of less that 100 years ago. For as much, the glaciers of mountain, although in regression almost everywhere in the world, are topics to strong multi-temporal variations that return the forecastings on this difficult point according to some specialists.
"The polar glaciers as those of the Spitzberg (to about hundred km of the North pole) move back since 1880, freeing big quantities of water (Laboratory of Géodynamique of the natural habitat and anthropisés, Clermont-Ferrand, 01/2004).
"The Arctic loses about 10% of his/her/its permanent ice layer every ten years since 1980 (NASA, 2003). In this region, the middle temperatures increased to a speed two times faster than elsewhere in the world during the last decades (ACIA, 11/2004).
The melting of the Arctic floe results in a loss of 15% of his/her/its surface and 40% of his/her/its thickness since 1979.
Finally, the floe reaches some records in term of surface loss: in September 2005, the floe represented 5,32 millions of km² only, for 7,5 millions km² in 1978 (National Snow and Ice Data Center, 09/2005). All models predict the disappearance of the Arctic floe in summer from here some decades, what won't be without consequence on the climate in Europe.
"The cyclonic season 2005 in the Atlantic North beat some records at a time in number of storms and in power of the cyclones.
"The intensity of the deep and slow oceanic circulation that redistributes the energy in the oceans decreases appreciably since 5 years.
"July 2006, some heatwaves touch a part of Europe and the lively North America notably a tension on the energy.
These observations depend on the systems of meteorological summaries that only exist in a number enough limited of country with statistics that rarely go back up beyond one century or one century and half. Moreover, the scientists work hard to represent the climatic variations of the two last thousands of years that could act as reference in the projections.

Of the alarming forecastings

All potential scripts of broadcasts foresee an increase of the concentrations of CO2, an elevation of the world middle temperature and the sea level during the 21 century. Indeed, the most optimistic hypotheses (stabilization of the broadcasts of GES to the level of 1990) reveal an increase all the same of about 1,5°C.
Considering the way of which develops himself the industrial activity, 2100 are the one where the concentration in CO2 will have doubled in relation to the pre-industrial era to rise to 560 ppm. The temperature of the Earth will rise then on average of 3°C of here to 2100.

Source: GIEC, 1995-2007	Evaluations in 1995 (in relation to 1990)	Evaluations in 2001 (in relation to 1990)	Evaluations in 2007 (in relation to 1980-1999)
Rise of the middle temperatures in 2100	+ 1°C to + 3,5°C	+ 1,5°C to + 5,8°C	+ 1,1°C to + 6,4°C
Elevation of the sea level until 2100	+ 0,15 to + 0,95 m	+ 0,08 to + 0,88 m	+ 0,18 to + 0,59 m
Concentration of CO² in the atmosphere until 2100	500 ppm	540 to 970 ppm	600 to 1 550 ppm

The climatic models
The different models of modelling of the climate found on the mathematical formulation of the physical principles that governs the interactions enter the continents, the oceans, ices and the atmosphere. These computer programs are sufficiently reliable to believe in their forecasting.

Toward climatic changes ?
The scientific community is unanimous: the aggravation of the greenhouse effect is mainly in progress at the origin of the climatic change that represents "a disruption anthropique dangerous of the climatic system". GIEC

One speaks therefore of global climatic change because his/her/its geographical extent is global and his/her/its features and consequences are varied and drag multiple repercussions on the human societies and the ecosystem of the Earth as the multiplication of the climatic anomalies.

Whereas he/it was recorded a few less than 50 meaningful events per year on the period 1970-1985, since 1995 one counts some about 120.