|Updated June 01, 2013
The "macro organism" Earth is feverish and panic all humanity, each flood, storm, tsunami and other earthquake pushed the anguish of men. The effects of global warming as announced, may well be felt sooner than expected. The estimates are alarming: a warming of 1.4 to 5.8 degrees Celsius is foreseen by the end of the century, it will be the largest increase in temperature known what the Earth from about 10 000 years. In the cooler period experienced ago our planet 20 000 years and the hottest period it has known 7,000 years ago, there were only 7. If the Earth's temperature increases with a century of 5.8 degrees Celsius as announced, the living world must adapt very quickly as it has ever had to do and some species will not survive.
The first consequences of this warming are already visible. Indeed we see every day that glaciers are retreating, as floods are becoming more catastrophic that times of drought back more and more frequently, that the Arctic sea ice is decreasing rapidly...
Image: The magnificent Perito Moreno glacier in Patagonia (Argentina).
Energy captured by the Earth
Our star, the sun sends us every day a considerable amount of energy, the average annual energy is in the high layers of atmosphere, of 342 W/m2 per day. The average albedo of the Earth is 30%, about 225 W/m2/j is absorbed by soil and lower atmosphere. By comparison, all humankind consumes very little power (less than 1 / 10 000th of the energy supplied by the Sun). Solar energy comes in the form of electromagnetic radiation. These radiation we face in the form of radio waves, infrared, visible light, ultraviolet, X-ray, gamma ray. Especially in the form of visible light and infrared energy that dissipates over land but 30% of the total radiation is directly reflected back to space. The rest is consumed by our macro organism on Earth, and finally reissued in space as infrared radiation. The greenhouse gases inhibit this radiation in part to leave our atmosphere in returning those that increase the infrared temperature of the planet.
Image: Solar energy comes in the form of electromagnetic radiation.
The greenhouse effect is the phenomenon that allows sunlight and prevents the heat generated is dissipated too quickly to the outside in order to raise the temperature inside the greenhouse.
Does the man may reduce the greenhouse effect to allow time to consider all the negative effects that this will lead?
Image: Launched on 19 October 2006, MetOp is the first satellite in polar orbit in Europe dedicated to operational meteorology.
CO2 carbon dioxide
Carbon dioxide (CO2) is the main greenhouse gases in their natural state, with water vapor.
Image: World production of crude oil and condensate (without gas, ethanol and other liquids which represents about 10 mb / d more).
Thanks to ice cores that we remove the soil of the Antarctic, up more than 3 500 meters deep, that we read in the past.
The satellites do a gain of temperature between 0.05 degrees Celsius and 0.13 degrees Celsius per decade in medium layers of the troposphere, against 0.18 ° C on the surface.
Image: The layers of the atmosphere: it distinguishes the troposphere (0-10 km), stratosphere (10-50 km), the mesosphere (50-80 km), the thermosphere (80-500 km) and above, l'Exosphère.
Greenland: The Alfred Wegener Institute (AWI) in 2007 confirmed the trend of decline in sea ice in the Arctic, both in area and thickness, twice as fine as in 2001, according the results of an international expedition, conducted under the International Polar Year.
The shiny surface of the ice reflects into space, most of the sunlight that reaches. With the melting of ice, shiny surface decreases and a larger amount of solar radiation is absorbed, so the oceans are warming faster and it becomes more difficult for the ice to reform.
Image: Greenland seen from space, thinning sea ice in the Arctic.
Sahara: Analysis of fossil dune formations in Chad by researchers at the CNRS in February 2006 (Science) has determined the age of the Sahara, the largest desert in the world. It would not be 86,000 years old, as we originally thought, but at least 7 million years.
Other clues found in cores made in the ocean off the African continent, suggest the existence in North Africa arid episodes prior to the latter.
Image: Satellite image of the largest desert on the planet, the Sahara (9 million km2).
Antarctica: NASA announced observing satellite early 2005 a melting ice of Antarctica on a surface area of California, a direct result of global warming, according to the U.S. space agency.
The comments of JPL (Jet Propulsion Laboratory) while involved so far, Antarctica had little or no heated with the exception of the Antarctic Peninsula, said Konrad Steffen, director of research institute in environmental sciences at the University of Boulder (Colorado, West), one of the authors of the study.
Image: Image of the Antarctic taken by the QuikScat satellite (the area is 14 million km2).
Nearly 5% of the sun's energy is emitted in the form of UV radiation. Those UV rays are classified into three categories according to their wavelength: UV-A, UV-B and UV-C. However, due to the absorption of UV by ozone in the atmosphere, 99% of UV light that reaches the surface of the land belongs to the range of UV-A. UV through the atmosphere even in cold weather or cloudy (they have nothing to do with the sensation of heat provided by the sun, which is due to infrared). UV rays are reflected by water (5% UV), sand (20% UV), grass (5% UV) and especially snow (85% UV). They are more numerous between 12 and 16h and high altitude as they crossed a finer layer of the atmosphere, and are less intercepted by ozone molecules. The hole in the ozone layer is potentially dangerous because of the harmful ultraviolet important. In the upper atmosphere of Earth, the ozone layer is a concentration of ozone that filters some of the ultraviolet rays emitted by the sun. This protective layer is threatened by pollution, especially by emissions of gases CFCs (chlorofluorocarbons), which rise into the upper atmosphere and catalyze the destruction of ozone, thus giving rise to the hole in the layer of ozone. As a measuring instrument, we can see the instrument GOMOS satellite Envisat. Antonio Ruiz de Elvira, Professor of Physics at the University of Alcala de Henares (Madrid), is optimistic about the evolution of the ozone layer.
According to him, the hole in the ozone layer has stabilized over the past fifteen years thanks to a 90% drop in emissions of chlorofluorocarbons.
Image: Image hole in the ozone layer 24/09/2006: credit NASA
In 2007, the size of the hole in the ozone layer is below that of 2006, "Although the hole is smaller than usual, we can not conclude that the ozone layer is recovering already," said Ronald van der A, a specialist in the Royal Netherlands Meteorological Institute (KMNI).
Image: Image hole in the ozone layer 18/11/2007: credit NASA
Since the 1950s, the sun has a phase of extraordinary activity. It is this conclusion reached that researchers at the Max Planck Institute for Research on Solar System, in collaboration with scientists Finnish, in an article published in the journal Physical Letters Revew. The development time of solar activity seems to follow very closely that of the mean temperature in the Earth's surface, which reflects the influence of the sun on the Earth's climate. Researchers have shown that the warming of the past 30 years can only partially be attributed to solar activity.
They can analyze it from several angles: oscillations, electromagnetic radiation, plasma and solar wind.
Image: Protuberances solar satellite views of Soho in January 2000 to May 2001. Credits: SOHO / EIT (ESA & NASA)
Overall ecological footprint
The global ecological footprint, established in the 1990s by MM. Mathis Wackernagel and William Rees, two researchers at the University of British Columbia in Vancouver, is the pressure exerted by mankind on nature. It assesses the productive surface necessary for a population to meet its consumption of resources and needs to absorb waste. This demand exceeds the limits in 2007 capacity of recovery.
Image: above, the ecological footprint by world region (productive area per person needed to meet its consumption of resources).
World energy demand
World oil demand will most likely continue to grow in the next thirty years. According to the International Energy Agency (IEA), this growth could be 60%, a forecast that remains fraught with uncertainties, as it is difficult to assess the evolution of populations, economies, ways of Life, technology and even geopolitical developments.
Image: tep (ton oil equivalent)
All volcanic eruptions affect the climate of local and regional to some, particularly important, discharging dust into the stratosphere and altering the global climate for a few months.
Volcanism implies a fall in temperatures in the short term but has been a powerful factor warming at the upper Cretaceous, there are about 80 million years. The temperature was 6 ° C higher than we know today, it was the hottest period of Earth's history marked by a major volcanism.
Image: Eruption of Krakatoa in 1997, projected volcanic dust in the atmosphere affect the Earth's climate for several years with a fall in mean temperatures of 0.25 ° C.
Image: article on volcanoes
The satellite altimetry can measure accurately (of the agenda mm), changes in average global sea from the center of the Earth.
It never fade since its formation. As against a warming would produce the opposite effect is to say that because of snowfall more abundant, the volume of ice would increase.
Image: The WWF 2009 report entitled "Climate feedbacks in the Arctic: global implications", provides a higher level rise of 1 meter by 2100.
Displacement of population
A study published in the journal Environment and Urbanization "of April 2007, identifies people facing the greatest risk because of the rising sea level and the increased intensity of hurricanes, as a result of change climate.
- On average, 14% of people in developed countries live in the area of 0-10 meters.
Image: The rainfall triggered floods, landslides and mud from landslides that kill and forcing the evacuation of hundreds of thousands of people. In July 2007, there were more than 4,000 homes destroyed, 386 000 evacuees and dozens of deaths in the provinces of Yunnan, Chongquing, Shandong and Xinjiang.
According to the study, published in September 2007 in the journal "Science" by American scientists of the Institute of Technology, Georgia and the National Center for Atmospheric Research, the number and duration of hurricanes is generally stable for 35 years on a global scale. However, the number and proportion of hurricanes in categories 4 and 5 (the maximum level Saffir-Simpson reference) have almost doubled since 1970. This phenomenon has been observed particularly in the Pacific Northwest, the Southwest Pacific and Indian Ocean. The temperature in the tropics five ocean basins where hurricanes form, increased by 0.5 degree Celsius from 1970 to 2004. However, one of the prerequisites for the formation of a hurricane is the temperature of surface water which must be at least 26.5 ° C on at least 60 m deep. It is still difficult to assess the real impact of global warming because the strength and number of hurricanes fluctuate naturally every 20-30 years."
Herve Le Treut, director of research at CNRS stated on 1 September 2007 to Agence France Presse that the emergence of hurricanes like Katrina could be the consequence of global warming.
Image: Hurricane Katrina view of the International Space Station (ISS). This is the first hurricane observed in the South Atlantic Ocean near Brazil (26 March 2004). Source Wikimedia commons.
Under the Kyoto Protocol, industrialized countries have to reduce their combined emissions of six key greenhouse gases during the five-year period 2008-2012 below 1990 levels.
Australia and the United States reported that they had no intention of doing so; together, they account for more than a third of greenhouse gases in the industrialized world.
IPCC Intergovernmental Panel on Climate Change's mission is to evaluate how clear and objective information on scientific, technical and socio-economic which are needed to better understand the scientific basis of risk change Climate of human origin. Prevent the possible consequences of this change and consider possible adaptation strategies. Its assessments are based mainly on scientific and technical publications whose scientific value is widely recognized. More than 1,000 scientists have participated in the latest report of the group I like writers (122, selected from a large number of candidates nominated by governments), contributors (515), examiners (420) or publishers (21).
ONERC the National Observatory on the Effects of Global Warming was created by the Act of 19 February 2001 to inform the public and policymakers about the consequences of global warming, and to provide the Government, Parliament, elected to communities and development actors, the elements of knowledge to develop a policy of prevention and adaptation.
IEA the International Energy Agency is an international organization designed to facilitate coordination of energy policies of member countries. The IEA was first provided to ensure the security of energy supplies (mainly oil) to support economic growth. It now intends to accomplish this objective, while contributing to environmental protection, reflection on climate change and market reforms.
Adaptation of ecosystems
Under the influence of rising temperatures, entire ecosystems are modified. Animal species as some butterflies, birds, colonize new territories, located at altitudes increasingly high, evidence of adaptation of species.
The emergence of milder winters encourage sedentary species at the expense of migrant species.
Image: Bohemian Waxwing: migratory that feeds into winter berries. Its food needs are important, a single bird eats 2 times its weight in one day.
The space satellite Envisat's Advanced Along Track Scanning Radiometer (AATSR), shows the confluence of the Rio Negro and Solimões downstream of Manaus, Brazil in the Amazon basin. The Amazon, the longest and most powerful river in the world sank slowly parallel between North 5th and 20th parallel south. The river has its source in the Peruvian Andes in the west of Lake Titicaca and empties into the Atlantic Ocean at the equator after crossing Peru and Brazil. The Amazon is responsible for 18% of the total volume of freshwater discharged into the oceans of the world and its drainage network has over 1000 rivers including the Rio Negro and Solimões. The Rio Negro is named after the color of decomposed plant that carries throughout his career. The Solimões carries him on 1600 km, sand, mud and silt that its water tinged with a yellowish color. The Amazon forest is the largest virgin forest in the world. It absorbs a huge amount of carbon dioxide, conservation of the Amazon forest is one of the biggest environmental problems of the early 21st century.
Virgin forests disappear gradually in the world at an alarming rate while their role is vital in the global climate of the planet.
Image: Manaus is a task seen as white, raised at the confluence of two rivers black and yellow, the Amazon basin.
It seems that scientists have great difficulty in unanimously affirming that global warming is man.
We note at once that nature unleashed more and more violently and at the same time, that the living world is struggling to adapt to these climatic fluctuations abandoning the weakest.
Video: In this accelerated video, there is a dangerously rapid rise in global temperature between 1880 and 2011.