By Bruce E. Johansen
Fuels burned today affect warming 30 to 50 years from now. Today's emissions will be expressed in the atmosphere in approximately 2040.
Levene argues that the Lloyd’s, like other international insurers, are preparing for an increase in climate catastrophes linked to global warming.
Also, performing his duties as chief of weapons inspectors in Iraq, Hans Blix said: "For me the issue of the environment is more worrying than peace and war. We will have regional conflicts and use of force, but no longer I think world conflicts will occur. But the environment, that is an acute and growing danger. I am more concerned about the environment than about any major military conflict. " Sir John Houghton, co-chair of the intergovernmental panel on climate change, agrees. "Global warming has already hit us," he said, "The impact of global warming is such that I have no doubts about describing it as a weapon of mass destruction." So what do they know that George W Bush doesn't know?
The time is the story / story, the climate is the plot / plot. We are charring the oceans, with serious consequences for life in them. By the dawn of the 21st century, levels of carbon dioxide in the oceans were rising faster than at any time since the age of the dinosaurs. In a report published in Nature on September 25, 2003, oceanographers Ken Caldeira and Michael E. Wickett wrote: "We found that oceanic absorption of CO2 from fossil fuels can result in greater pH changes over the next several centuries. , that any inferred changes in the geological history of the last 300 million years, with the possible exception of those resulting from extreme and unusual events such as the impact of a "fireball" or a catastrophic release of methane hydrate (a "fireball" it is a large extra-terrestrial body, usually at least half a mile in diameter, perhaps larger, striking the earth at a speed roughly equal to that of a bullet moving through the air.)
Rising levels of carbon dioxide in the oceans could threaten the health of various marine organisms, starting with plankton at the base of the food chain. "If we continue on the path that we are traveling, we will produce changes greater than those experienced in the past 300 million years - with the possible exception of unusual and extreme events such as the impact of comets," warned Caldeira of the Lawrence Livermore National Laboratory. Since carbon dioxide levels began to be systematically measured worldwide in 1958, its concentration in the atmosphere has increased by 17 percent.
Until now, some climate experts had claimed that the oceans would help control the rise in carbon dioxide by acting as filters. However, Caldeira and Michael Wickett said that carbon dioxide that is released from the atmosphere enters the oceans as carbonic acid, gradually altering the acidity of ocean water. According to their studies, the change produced in the last century has already reached the magnitude of the change that occurred in the 10,000 years that preceded the industrial era. Caldeira pointed to acid rain, a product of industrial emissions, as the possible precursor to changes in the oceans. "Most marine life resides on the surface, where the greatest change would be expected, but deeper marine life may turn out to be more sensitive to these changes," Caldeira said.
Marine plankton and other organisms whose skeletons or shells contain calcium carbonate, which are dissolved with acidic solutions, can be particularly vulnerable. Coral reefs, which are already affected by pollution; rising ocean temperatures; and other noxious agents are composed almost exclusively of calcium carbonate. "It is difficult to predict what is going to happen because we have not really studied the extent of the impact," said Caldeira. "But we can say that if we continue with our activities as before, we will see significant changes in the acidity of the world's oceans.
Along the same lines, warming seas are also devastating plankton, eroding the ocean food chain. Global warming is contributing to an "ecological melt" with devastating effects on fishing grounds, flora and fauna. The "melting" begins at the bottom of the food chain, as the rise in temperature of the seas kills plankton. Seabird populations and fish stocks are declining as well.
Scientists at the Sir Alistair Hardy Foundation for Ocean Science in Plymouth, England, who have been monitoring the growth of plankton in the North Sea for more than 70 years, have said that the unprecedented warming of the North Sea results in the displacement of plankton hundreds of miles to the north. This has been replaced by a smaller warm-water species, which is less nutritious. The overfishing of cod and other species had some impact, but the fish stocks have not recovered after the reduction of the allowed fishing quotas.
The number of salmon returning to British waters is now half of what it used to be 20 years ago, and the decline in the plankton population is a central factor. "There has been a regime change and the entire ecology of the North Sea has changed dramatically," said Dr. Chris Reid, director of the Foundation. "We are witnessing a collapse in the system as we know it. The catch of salmon and cod has already declined and we are getting smaller fish. We are looking at evidence of climate change in a large-scale ecosystem.
We are likely to see further warming, with temperatures similar to those of the Atlantic coast of Spain or even further south, generating a complete change in the ecology. "
Research by the British Royal Society for the Protection of Birds has established that seabird colonies off the coast of Yorkshire and the Shetlands have suffered their worst breeding season this year since records began, with abandonment of their nests. The population of seabirds is declining in large part because the lanzones are declining. Lanzones feed on plankton. This study focused on kittiwakes, a species of seabird, but other species that feed on lanzones, such as puffins and auk, have also been seriously affected.
Lanzones also make up, by weight, one-third to one-half of the North Sea catch. Danish factory ships have caught them in huge quantities, to be turned into small balls of food for pigs and fish. During the summer of 2003, the Danish shipping fleet caught just 300,000 tonnes of its 950,000 tonne quota, a record low catch.
Beware Of Methane Burps!
The combustion gases from yesterday's 4 × 4 trucks do not result in today's rising temperatures, not immediately. Through a complicated feedback loop, fuels burned today affect warming 30 to 50 years from now. Today we are looking at temperatures related to fuel emissions from about 1960, when fuel consumption was much lower. Today's fuel emissions will be expressed in the atmosphere in approximately 2040.
Rising levels of greenhouse gases near the surface keep the heat there, preventing the advance of radiation to the higher layers of the atmosphere. As the surface warms, the stratosphere cools. The chemical reactions that consume the ozone that protects us from ultraviolet radiation accelerate as the air cools. Thus, the area where ozone has dropped below appropriate levels, in Antarctica, remains close to record size despite the fact that chlorofluorocarbons, the culprit in ozone depletion, were banned more than 15 years.
In his book "When Life Almost Died: The Greatest Mass Extinction of All Time" (London: Thames and Huston, 2003) Michael J. Benton describes a mass extinction at the end of the Permian period, approximately 250 million years ago, when at least 90 percent of life on earth died. The extinction probably started with massive volcanic eruptions in Siberia.
According to current theories, the eruptions introduced enormous amounts of carbon dioxide into the atmosphere, causing a number of biotic reactions that accelerated global warming by approximately 6 degrees Celsius. In a chapter titled "What Caused the Greatest Catastrophe of All Time?" Benton outlines how the warming (which was accompanied by anoxia or lack of oxygen) could have fed itself: "Perhaps the greenhouse effect of the late Permian period was simple.
Carbon dioxide was released from the eruption of Siberian volcanoes, leading to a global temperature rise of about 6 degrees Celsius. The cold polar regions turned warm and the tundra thawed. The "melt" must have penetrated the pockets of methane hydrate located around the polar oceans, and huge volumes of methane must have exploded towards the surface of the oceans in huge bubbles.
This extra carbon entry into the atmosphere caused further warming, which may have melted, in turn, more of the methane hydrate reserves. In this way the process continued, faster and faster. Natural systems that normally reduce carbon dioxide levels were unable to operate and eventually the system spiraled out of control, causing the largest collapse in the history of life. "
The lack of oxygen from this huge global methane outpouring left land animals struggling to breathe, causing the largest mass extinction in Earth's history, new research suggests. Greg Retallack, an expert on prehistoric soils at the University of Oregon, has speculated that the methane's "ejection" itself was of such magnitude that it caused the mass extinction from lack of oxygen, fatal in terrestrial animals. Bob Berner of Yale University has calculated that the cascade of effects on humid land areas and coral reefs may have reduced atmospheric oxygen levels from 35 percent to just 12 percent in 20,000 years. Marine life must also have suffocated in the oxygen-starved waters.
Today, events from 250 million years ago are more than of academic interest, because the 6 degrees Celsius that Benton estimates triggered these events, is almost equal to the IPCC forecast of the increase in temperature of planet Earth by the end of this year. century.
In Abrupt Climate Change (2002) Richard B. Alley wrote that climate can change rapidly (up to 16 degrees Celsius in a decade or two) "when gradual causes push the Earth system to the limit. Something like the increasing pressure of a finger who eventually flips a switch and flips on the light…. " Half of the global warming of the North Atlantic since the last ice age was reached, Alley writes, in a decade.
Greenland's temperature record, according to Alley's study, looks more like an irregular row of sharp teeth than a gradual passage from one era to another. According to Alley, "Global warming projections predict an increase in global rainfall, increased rainfall variability, and summer droughts in the interior of several continents, including grain-producing regions. These changes could produce more floods and droughts. " Human emissions of greenhouse gases can add enough to trigger that rapid change.
By 2000, the hydrologic cycle appeared to be changing faster than temperatures. Warmer air holds more humidity, making the rain (and sometimes snow) heavier. Warmer air also increases evaporation, paradoxically intensifying the drought at the same time. With sustained warming, habitually humid locations generally appear to be receiving more rain than before; dry places often receive less rain and are prone to more persistent droughts.
In many places, droughts or floods have become the meteorological regime of the day. Atmospheric humidity increases faster than temperature; In the United States and Europe, the increase in atmospheric humidity was 10 to 20 percent from 1980 to 2000. "That is why the impact of global warming is seen especially in intense storms and floods like the ones we have seen in Europe "Kevin Trenberth, a scientist working with the National Center for Atmospheric Research (NCAR), told the Financial Times in London.
As if they came to corroborate climate models, the summer of 2002 featured a number of extreme weather events, especially in terms of rainfall. Excessive rain swept through Europe and Asia, flooding cities and towns and killing at least 2,000 people, while droughts and high temperatures scorched cities in the eastern and western United States. Climate change skeptics argued that weather is always variable, but other observers noted that extremes seemed to be more frequent than before. A year later, following the episodic floods during the summer of 2002, Europe experienced some of the highest (and most sustained over time) temperatures in its recorded history, causing (according to various estimates) between 19,000 and 35,000 deaths. Up to 80% of crops were damaged in eastern Germany, the scene of one of the worst floods of 2002.
"In a warmer climate, the chances of finding yourself with too much or too little are greater," said Dr. Wallace, a professor of atmospheric sciences at the University of Washington. Scientists working for the government have measured an increase in downpour storms in the United States over the past century. "Over the past 50 years, said Wallace, winter rainfall in the Sierra Nevada has been increasingly coming in the form of rain, increasing the risks of flooding, rather than snow, which is what provides water to farmers and wells. alike as it melts in spring.
The World Water Council report compiled statistics indicating that between 1971 and 1995, floods affected more than 1.5 billion people worldwide, or 100 million people a year. Approximately 318,000 have died and more than 18 million have been made homeless. The economic cost of these disasters has been estimated at approximately $ 300 billion in the 1990s while in the 1960s it was 35 billion. Global warming is causing changes in weather patterns as populations migrate to vulnerable areas, increasing the cost of individual weather events, said William Cosgrove, vice president of the World Water Council. Scientists cited by the World Water Council hope that the climatic changes that occur in the course of the 21st century will bring intense and shorter rainy seasons in some areas, as well as longer and more intense droughts in other areas, putting some crops and crops at risk. species, and causing a reduction in world food production.
Examples abound of extreme increases in precipitation. November 2002, December 2002, and January 2003 were Minneapolis-St Paul’s driest months in recorded history. This was followed by the months from June to October that were the rainiest in more than 100 years. In December 2002, Omaha experienced its first month with no measurable rainfall. In March 2003, having endured the driest year in its recorded history in 2002, Denver, Colorado, recorded 30 inches of snow in a storm. Some areas of the front of the sierra, threatened by drought, received up to 10 feet of snow in the same storm. After that storm, the dry weather returned.
About half of the United States was under severe drought conditions during the summer of 2002. The drought was occasionally interrupted by torrential rains. On September 13, 2002, for example, Denver, threatened by drought, was inundated by deluge from a fast-moving electrical storm that caused widespread flooding.
Similar events occurred in Salt Lake City. Ten days later, a downpour flooded Atlanta, also threatened by drought. On September 10, 2002, the equivalent of six months of rain, fell in just a few hours in the departments of Gard, Herault and Vaucluse in southern France, drowning at least 20 people. In the village of Sommieres, near Nimes, a usually small stream overflowed to a width of 300 meters, disrupting land traffic.
Chicago's suburbs received 20 to 33 centimeters of rain on the night of August 12, 2002, in a summer that included devastating floods in Prague and Dresden, as well as parts of southern China. India had a variable monsoon, some areas were flooded while others experienced droughts. The severe flooding of Europe during 2002 may be an indicator of an emerging pattern, according to Jens H and Ole B. Christensen, who modeled precipitation patterns in Europe under warming conditions that may be prominent in the area, from the 2070 through 2100. "Our results," they wrote in Nature, "indicate that severe flood episodes may become more frequent, despite the general trend toward drier summers." The trend toward drought or flooding will intensify as warming distorts the hydrological cycle. A warming atmosphere will contain more water vapor, which will provide a greater potential to release latent heat during the formation of low pressure systems, possibly intensifying those systems and also making more water available. for precipitation. "Christensen and Christensen wrote.
The amount of mean annual precipitation in the United States has been increasing by 2 to 5% per decade, according to atmospheric scientist Ken Trenberth and his colleagues (who write in the bulletin of the American meteorological society Bulletin of the American meteological Society) with "most of the increase related to temperature and, therefore, to the atmospheric water retention capacity …… there is clear evidence that the average rainfall has changed in the United States…. less rain - or snowfall is expected- but more intense ". Individual storms will be fueled by latent heat shedding, which provides even more moisture to individual storms.
Generally, higher temperatures increase evaporation, with some compensatory cooling when water is available. Increased evaporation intensifies the drought, which, to some degree, exacerbates itself as moisture is depleted leading to "increased risk of heat waves and fires in association with those droughts, as once the moisture in the soil has been depleted, then all the heat is directed to the rise in temperature and the wilting of the plants. "
In mountainous regions, Trenberth wrote, "" Glaciers "(snowpack) are a vital resource, not only for skiers, but as a source of fresh water in the spring and summer when the snow melts. shortens the snow season with more precipitation falling in the form of rain rather than snow, melting existing snow earlier, and causing more evaporation and weathering. All of these factors contribute to shrinking glaciers. In the summer of 2002, in the In the western part of the United States, exceptionally small glaciers and subsequent low soil humidity have likely contributed substantially to the intense widespread drought, due to the importance of recycling (in the hydrologic cycle). Could this be a sign of the future? ?
Insurance companies, whose business is betting on the future, are watching the weather, and they're worried.
* Published at http://www.lafuna.nu