Scientists must end their continuing for twenty years, the reluctance to recognize the link between individual natural disasters: hurricanes, floods and drought, reports of which are so often full of the news — and drastically, from their previous non-committal stance, which today many consider the increasingly untenable.
British, American scientists studying climate, as well as researchers from other parts of the world, have formed a new international alliance that aims to study extreme weather events, which can be attributed to global warming caused by the greenhouse effect of carbon dioxide emissions.
According to scientists, is now unacceptable to claim that extreme weather events just "meet" climate change. Now they are going to evaluate every abnormal weather phenomenon in terms of the likelihood that it is aggravated or even caused by the global temperature rise observed in the past century.
Perhaps this would be quite difficult, since science "explanations weather" is still in the early stages of its development, and it is likely that the conclusions will be attacked "skeptics", calling into question what else the relationship between industrial emissions dioxide carbon and an increase in global average temperatures.
In the past, scientists are extremely reluctant to link individual weather anomalies to climate change, arguing that the natural variability of the weather conditions make it virtually impossible to establish any definite connections other than a possible general conformity with the situation expected according to research based on computer models.
Currently, however, a growing number of scientists involved in the study of climate change, are ready to take a much more proactive stance, arguing that the climate has changed sufficiently that it can affect the likelihood of extreme weather events, whether it's a hurricane, flood or unusual destructive drought.
"Of course, we have moved away from the position of the claim that nothing can be said about the relationship of natural disasters to climate change" — says Peter Scott (Peter Stott), a leading scientist and meteorologist in the weather service Hadley Center in Exeter.
"It is clear that climate change is happening now, which means that the moisture content in the atmosphere has increased, and obviously there is the possibility of more violent storms and heavy precipitation more rainfall."
Kevin Trenberth (Kevin Trenberth), an authority, a senior fellow at the National Center for Atmospheric Research, USA (NCAR) in Boulder, Colorado, also believes that it is time to pay attention to the link between extreme weather events and global climate, in which they arise .
"The environmental conditions in which hurricanes are formed, changed by human activities, in particular, has become warmer and humidity increased, compared to what it was 30-40 years ago," — said Dr. Trenberth.
"The additional water vapor is invisible until it starts to form a hurricane, and the moisture and heat, contributing to the development of hurricanes, are now much higher. According to this model in the sub-tropics will become drier and in the monsoon troughs and high latitudes — more humid. This scheme we observe in reality. "
Weather Center and NCAR have joined forces with other organizations involved in climate issues, including the influential National Oceanic and Atmospheric Organization USA (NOAA), to carry out detailed studies extreme weather events such as last year's flooding in Pakistan, to identify possible "signal" climate change as the likely cause of these disasters.
A group of researchers from these organizations has organized a coalition, known definition of climate-related events (Attribution of Climate-Related Events), which is preparing a report on the subject, it is assumed that it will be released at the end of this year at a meeting in the framework of the study of global climate change ( World Climate Research Programme) in Denver. Scientists suggest in the future to assess each unusual natural phenomenon in terms of the possibility that it is linked to global warming, and put the results on the Internet.
"If you look at the situation in the world, you can see a lot of evidence that there is an increase heat waves, and floods and droughts, and increased rainfall, and sharp fluctuations in temperature," said Dr Stott.
"The records of observations around the world quite clearly indicates a change in extreme temperature and precipitation limit. But we can not do this immediately jump in and say that this or that particular event directly caused [climate change], because, as you know, natural variations can also play a significant role. "
"We develop our science, introducing quantitative measures to assess the connections to be able to make more definitive statements about how much the risk. These things need to look closely, to justify a change or risk the chance of such an event. "
Dr. Stott and his colleagues have conducted a study of the unusual heat wave in Europe in 2003, when due to heat-related illnesses claimed about 35,000 people; carefully studied them and devastating floods in the UK in 2000, when insurance policies were paid 1 , 3 billion pounds and destroyed ten thousand dwellings in the year in England and Wales has been registered with the most rainy autumn 1766.
In both cases, scientists have found that the contribution of greenhouse gas emissions that are the product of human activity, significantly increased the risk of such disasters. The group also examined unusually warm weather in the UK in April this year, in April this year was the warmest recorded since 1659 in central England record, and 0.5 degrees Celsius warmer than the previous warmest April.
In addition, this year, an unprecedented number of tornadoes struck the southeast coast of the United States, add to this the flooding of major rivers such as the Mississippi and Missouri. Many people wonder, is not there due to global warming. Previously, scientists did not want to link these separate natural disasters to climate change, but Dr Trenberth believes that this view is mistaken.
"I will not say that we can not bind a separate event with these things. Instead, say something else: change the environment in which there are all these storms, "said Dr Trebert The Independent.
"This is not a direct result of the greenhouse effect, the memory system, and the main memory is stored in the oceans, oceans is hot at depth, and we can measure it. I say that to any event affecting climate change, and for the most part we notice when they are outside of the old natural fluctuations, and since natural fluctuations are very large, very often we do not notice. "
"When what used to take 4% of the time, began to occupy 10% of the time, we are starting to notice. The main way to detect climate change is changing the emergency disasters — when we register a new record level. "
From the report of the insurance company Munich Re is clear that 2010 was one of the worst in the number of recorded natural disasters, nine-tenths of which have been associated with extreme weather events, such as the flooding in Pakistan and eastern Australia, and an unprecedented heat wave in Russia, out- for which, it is estimated that left at least 56,000 people, so it can be safely called the deadliest natural disaster in history.
"This steady trend can no longer be explained solely by natural fluctuations in the climate. Most likely, some contribution to these climate warming is making the oceans "- says Peter Hepp (Peter Hoppe), author of the report Munich Re.
Tornado, USA, 2011 Tornadoes and severe storms that hit the south-east coast of the United States in April of this year, killed more than 220 people, and only in Alabama, the death toll was 131. Fifteen people died in Tuscaloosa, entire sections of the city were destroyed.
The heat, the United Kingdom, 2011 in April 2011 was the hottest since 1659, when England began registration weather. Sun lovers flocked to hotels in St Ives; however, there was a danger of drought. Precipitation in the UK this month amounted to only 52% of the mean.
Drought, Brazil, in 2005 the Amazon have suffered from the worst drought in more than a hundred years. Floodplain of the river dried up, and the people moved on foot or by bicycle, where previously the only means of transport was the river and boats.
Flood, USA, 2005 Hurricane "Katrina" became one of the five deadliest hurricanes in U.S. history, it caused the destruction of New Orleans, when the water perehlestnulas through dams. About 90% of residents in the south-eastern Louisiana were evacuated.
Steve Connor (Steve Connor) — scientific editor of The Independent.