Impact
"Rising atmospheric carbon dioxide levels are causing permafrost to melt, ice shelves to collapse - and climatologists to warn that if emissions continue at their current rate, the next generation will be subject to unprecedented environmental devastation." (Popular Science - July 2006)
The burning of fossil fuels, land clearing and agriculture- all human activities- have contributed to a buildup of greenhouse gases (carbon dioxide, methane, nitrous oxide, ozone) in the Earth’s atmosphere. According to Larry J. Schweiger, National Wildlife Federation President and Chief Executive Officer, "We have embarked on a massive planetary experiment outside the range of human experience, putting nearly a trillion tons of carbon dioxide into the atmosphere in the past 150 years, raising atmospheric CO2 levels by more than 36 percent."
There is no disputing that the surface temperatures of our oceans are 1.6 degrees (F) warmer and 8-10 inches higher then they were in the last century. Already this small change has been directly linked to melting glaciers, polar ice cap deterioration, rising sea levels, and the increased intensity of hurricanes. This increase could cause sea levels to rise, extreme weather events such as floods, droughts, heat waves, and hurricanes, changes in agricultural yields, glacier retreats, lower streamflows in the summer months, and could lead to the extinction of some animals.
Alaskan Glacier Melt - U.S. Geological Survey
Photos. Source: The San Francisco Chronicle
In a July 27, 2006 article titled ' Making Money By Feeding Confusion Over Global Warming ', "In the last several years a growing body of research has led virtually all credible climate scientists to the same conclusion. For example, the Intergovernmental Panel on Climate Change -- an international group of hundreds of climate scientists -- with 90% certainty concluded that "there is new and stronger evidence that most of the observed warming observed over the last 50 years is attributable to human activities." The National Academies of Sciences said the earth is likely hotter than it has been in at least the last 2,000 years.
Sea Level Rise
Global sea levels will rise as much as 3 feet with the loss of shelf ice in Greenland, devastating coastal areas worldwide. If we continue our present course and global warming melts all the ice sheets worldwide, especially the Antarctic, sea levels will rise considerable more. (see map)
The flow of ice from glaciers in Greenland has more than doubled over the past decade. The Arctic has already lost 40 percent of its ice by volume, 20 percent by surface, drastically increasing absorption of solar heat up north as sunlight-reflecting ice vanishes. The region has warmed 5 degrees F, largely a result of retreating ice. Greenland’s glaciers are sliding toward the sea and calving twice as fast as they did 5 years ago. A study published in the peer-reviewed journal Science reported that 87 percent of 244 Antarctic Peninsula glaciers have retreated during the past 50 years. New data from the British Antarctic Survey hint that the West Antarctic Ice Sheet's 7 million cubic miles of ice thinning dangerously. If melted, the ice sheet will raise sea levels between 16 and 50 feet worldwide.
Changing Weather
The negative effects of global warming are already well under way. The weather is drastically changing. The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years. Heat waves will be more frequent and more intense. Floods, droughts and wildfires will occur more often.
A July 2005 study in the journal Nature, published by noted climate scientist Kerry Emanuel of the Massachusetts Institute of Technology, examined data from thousands of hurricanes worldwide over the past 50 years. Emanuel concludes in an August 2005 study that wind speeds and durations of hurricanes in the Atlantic and Pacific have increased by 50% since the 1970s. Emanuel attributes this upward trend in the intensity of hurricanes at least partially to human influences on warming surface temperatures. "I see a large global warming signal in hurricanes," Emanuel said of his study.
Other studies support this. A March 2004 study conducted by Thomas R. Knutson of NOAA/Geophysical Fluid Dynamics Laboratory and Robert E. Tuleya of the Center for Coastal Physical Oceanography finds that “if the frequency of tropical cyclones remains the same over the coming century, a greenhouse gas-induced warming may lead to a gradually increasing risk in the occurrence of highly destructive category-5 storms.” They note that previous studies have found that idealized hurricanes, simulated under warmer, high-CO2 conditions, are more intense and have higher precipitation rates than under present-day conditions.
Methane
Melting of the permafrost, which has been frozen since the last ice age, will release an estimated 200 gigatons to 800 gigatons of carbon (the total human carbon output is only about 7 gigatons a year). Even worse, huge volumes of methane will be released as the permafrost melts.
According to Larry J. Schweiger, "Russian scientists warn that 70 to 80 billion tons of methane and other carbon compounds, with 20 times carbon dioxide’s heat trapping capacity per molecule, may soon escape into the atmosphere as permafrost thaws in Siberia. This release could trigger catastrophic increases in global warming."
The National Wildlife article titled "Alaska Meltdown" By Lisa W. Drew, states that "A massive amount of natural methane has been trapped for millennia in the frozen arctic tundra—400 billion tons. Northern mud contain 3,000 times as much methane as is currently found in the atmosphere. Melting permafrost could release that methane, which would enter the atmosphere, increase the rate and intensity of global warming and spur the release of yet more methane from ocean bottoms. Methane emissions increase rapidly in a warming climate. So even as methane alters climate, it is also affected by climate—another dangerous positive feedback loop. Methane garners its own tipping point in the form of methane clathrates, the 1- to 2.5-trillion-ton reservoir of frozen methane underlying the ocean floor and the Arctic permafrost. A study by Russian and American researchers in Science published in June announced, is a heretofore unknown global carbon source in a deep layer of permafrost known as loess, which contains an estimated 500 gigatons of carbon. The loess has never been accounted for in climate warming models.
"Once global warming reaches a level that speeds methane into the atmosphere, there may be no turning back. How deadly is this threat? Scientists believe that a release of massive amounts of methane into the atmosphere some 250 million years ago caused the extinction of 94 percent of all marine species known from the fossil record. In the seas, coral reefs almost vanished, as did forests on land. Some areas did not recover their biological diversity for more than 100 million years."
"The vanishing ponds of Alaska and Siberia may be a warning for all nations to take a preemptive strike against global warming rather than wait until the warning signs turn to disaster,” says Jeremy Symons, director of National Wildlife Federation’s global warming campaign.
While scientists try to come to grips with new evidence from 800,000 years-old Antartica ice cores that shows atmospheric carbon dioxide at unprecedented levels, a potentially deadlier climate change menace has emerged from methane released by melting permafrost from Siberia. A study published by the scientific journal Nature shows methane, a greenhouse gas 23 times more powerful than carbon dioxide, is being released into the atmosphere at a rate five time faster than previously thought. Global warming gases trapped in the soil are bubbling out of the thawing permafrost in amounts far higher than previously thought and may trigger what researchers warn is a climate time bomb.
Methane — a greenhouse gas 21 times more powerful than carbon dioxide — is being released from the permafrost at a rate five times faster than thought, according to a study being published Thursday in the journal Nature. The findings are based on new, more accurate measuring techniques.
The source of the methane is melting permafrost in Siberia, which is thawing due to global warming already in process due to increased concentrations of carbon dioxide in the atmosphere from the burning of fossil fuels and other sources.
A problem for concerned scientists is that the issue of global warming is no longer a question of just cutting down on the burning of fossil fuels to decrease carbon dioxide levels. Scientists are worried that the thawing Siberian permafrost, called yedoma, and the resulting bubbles of methane and carbon dioxide gas being released into the atmosphere is causing a greenhouse feedback cycle, which will result in further global warming.
The amount of carbon trapped in yedoma which could be released as both methane and carbon dioxide has been estimated in earlier study to be as much as 100 times the quantity of carbon dioxide released each year by fossil fuel burning.
What worries scientists the most is that if a feedback global warming process is indeed in process, with increasing quantities of greenhouses gases leading to increased warming and further permafrost thawing, there is no known way to stop it.
Extinction
Researchers at Bristol University have discovered that a mere 6 degrees of global warming was enough to wipe out up to 95 per cent of the species which were alive on earth at the end of the Permian period, 250 million years ago.
By 2050, rising temperatures exacerbated by human-induced belches of carbon dioxide and other greenhouse gases could send more than a million of Earth's land-dwelling plants and animals down the road to extinction, according to a recent National Geographic study.
Assuming mid-range Intergovernmental Panel on Climate Change global warming scenarios, between 17 and 35% of all species will become extinct by 2050. In his 2002 book “The Future of Life”, E. O. Wilson estimates that 50% of all plants and animals will be extinct by 2100. "It is naive to assume that humans can survive an extinction event that wipes out as much as 50% of all other species. We are perhaps the most complex life form and most dependent on the rest of the inhabitants of the biosphere. While we pride ourselves on our adaptability and our technological prowess, there are limits to adaptability and our technology is causing most of our problems." 4
Most researchers agree that even small changes in temperature are enough to send hundreds if not thousands of already struggling species into extinction unless we can stem the tide of global warming. And time may be of the essence: A 2003 study published in the journal Nature concluded that 80 percent of some 1,500 wildlife species sampled are already showing signs of stress from climate change.
The key impact of global warming on wildlife is habitat displacement, whereby ecosystems that animals have spent millions of years adapting to shift quickly. Ice giving way to water in polar bear habitat is just one example of this. Another, according to The Washington Post, is the possibility that warmer spring temperatures could dry up critical breeding habitat for waterfowl in the prairie pothole region, a stretch of land between northern Iowa and central Alberta.
Affected wildlife populations can sometimes move into new spaces and continue to thrive. But concurrent human population growth means that many land areas that might be suitable for such "refugee wildlife" are already taken and cluttered with residential and industrial development. A recent report by the Pew Center for Global Climate Change suggests creating "transitional habitats" or "corridors" that help migrating species by linking natural areas that are otherwise separated by human settlement.
Beyond habitat displacement, many scientists agree that global warming is causing a shift in the timing of various natural cyclical events in the lives of animals. Many birds have altered the timing of long-held migratory and reproductive routines to better sync up with a warming climate. And some hibernating animals are ending their slumbers earlier each year, perhaps due to warmer spring temperatures.
To make matters worse, recent research contradicts the long-held hypothesis that different species coexisting in a particular ecosystem respond to global warming as a single entity. Instead, different species sharing like habitat are responding in dissimilar ways, tearing apart ecological communities millennia in the making.
And as wildlife species go their separate ways, humans can also feel the impact. A World Wildlife Fund study found that a northern exodus from the United States to Canada by some types of warblers led to a spread of mountain pine beetles that destroy economically productive balsam fir trees. Similarly, a northward migration of caterpillars in the Netherlands has eroded some forests there.
According to Defenders of Wildlife, some of the wildlife species hardest hit so far by global warming include caribou (reindeer), arctic foxes, toads, polar bears, penguins, gray wolves, tree swallows, painted turtles and salmon. The group fears that unless we take decisive steps to reverse global warming, more and more species will join the list of wildlife populations pushed to the brink of extinction by a changing climate.
Here are 5 shocking examples of what's happening right now to our wildlife.- Surprised researchers found dead polar bears far out at sea last year. Forty percent of the ice in the Arctic has already melted and polar bears must travel further and further to find food. The bears simply couldn't swim far enough to reach the receding ice and many of them drowned!
- Thousands of caribou calves have been swept to their deaths when migrating across rushing rivers that should have been iced over.
- Peguins struggle for their lives because they cannot find enough of their main food source, krill, which are dying off because of rising ocean temperatures.
- Coral reefs have undergone extensive damage, called coral bleaching, due to increasing temperature of ocean waters. In one year alone, 16% of the worlds coral reefs were wiped out.
- Beautiful monarch butterflies experienced a mass die-off in 2002 due to the hazards caused by the increased rainfall attributed to global warming; scientists fear that this is the first of many similar incidents.
Disease
According to HealthNewsDigest.com, climate change accelerates the spread of disease primarily because warmer global temperatures enlarge the geographic range in which disease-carrying animals, insects and microorganisms--as well as the germs and viruses they carry--can survive. Analysts believe that, as a result of global temperature rises, diseases that were previously limited only to tropical areas may show up increasingly in other, previously cooler areas.
For example, mosquitoes carrying dengue fever used to dwell at elevations no higher than 3,300 feet, but because of warmer temperatures they have recently been detected at 7,200 feet in Colombia’s Andes Mountains. And biologists have found malaria-carrying mosquitoes at higher-than-usual elevations in Indonesia in just the last few years. These changes happen not because of the kinds of extreme heat we’ve experienced in recent months, but occur even with minuscule increases in average temperature.
But extreme heat can also be a factor, and the nexus of global warming and disease really hit home for North Americans in the summer of 1999, when 62 cases of West Nile virus were reported in and around New York City. Dr. Dickson Despommier, a Columbia University public health professor, reports that West Nile Virus is spread by one species of mosquito that prefers to prey on birds, but which will resort to biting humans when its normal avian targets have fled urban areas during heat waves.
“By reproductive imperative, the mosquitoes are forced to feed on humans, and that’s what triggered the 1999 epidemic,” Despommier says. “Higher temperatures also trigger increased mosquito biting frequency. The first big rains after the drought created new breeding sites.” He adds that a similar pattern has been recognized in other recent West Nile outbreaks in Israel, South Africa and Romania.
Bird flu is another example of a disease that is likely to spread more quickly as the Earth warms up, but for a different reason: A United Nations study found that global warming--in concert with excessive development--is contributing to an increased loss of wetlands around the world. This trend is already forcing disease-carrying migrating birds, who ordinarily seek out wetlands as stopping points, to instead land on animal farms where they mingle with domestic poultry, risking the spread of the disease via animal-to-human and human-to-human contact.
A Congressionally-mandated assessment of climate change and health conducted in 2001 predicted that global warming will cause or increased incidences of malaria, dengue fever, yellow fever, encephalitis and respiratory diseases throughout the world in coming decades. The assessment also concluded that insect- and rodent-borne diseases would become more prevalent throughout the U.S. and Europe.
The news isn’t good for less developed parts of the world either. Researchers have found that more than two-thirds of waterborne disease outbreaks (such as cholera) follow major precipitation events, which are already increasing due to global warming.
National Security and Global Instability
Global climate change could have an increasing effect on U.S. strategic interests and will likely pose "a serious threat to America's national security," according to a panel of retired generals and admirals.
Rising sea levels could swamp low-lying countries, causing mass migrations and conflicts over land. Meanwhile, water shortages and flooding could lead to or worsen political conflicts and conflicts over food and water -- and the United States could be drawn into these conflicts.
"Climate change exacerbates already unstable situations," former U.S. Army Chief of Staff and study co-author Gordon Sullivan told Associated Press Radio. "Everybody needs to start paying attention to this."
The possible military and political changes will come over the next 30 to 40 years, according to the report.
"Unlike the problems that we are used to dealing with, these will come upon us extremely slowly, but come they will, and they will be grinding and inexorable," retired U.S. Navy Vice Adm. Richard Truly said in the report.
Other recent studies have come to similar conclusions. A March report by the Global Business Network found that rising sea levels and other climate change consequences could lead to strife in countries like Bangladesh, parts of which may become uninhabitable.
"Just look at Somalia in the early 1990s," Peter Schwartz, one of the authors of that study, told the New York Times. "You had disruption driven by drought, leading to the collapse of a society, humanitarian relief efforts, and then disastrous U.S. military intervention. That event is prototypical of the future."
Climate scientists and experts generally agreed with the report's predictions.
"The evidence is fairly clear that sharp downward deviations from normal rainfall in fragile societies elevate the risk of major conflict," Marc Levy, associate director of the Earth Institute at Columbia University, told the New York Times. "It seems irresponsible not to take into account the possibility that a world with climate change will be a more violent world."
Some experts said the report's timeline might be too alarmist. Environmental scientist Terry Root of Stanford University told the Associated Press that some of the changes may take longer than 30 years to occur. However, she said that the report was "pretty impressive" and that the changes it predicts will occur sometime.
"We're going to have a war over water," Root told the Associated Press. "There's just not going to be enough water around."
The report was issued by the Center for Naval Analyses, a government-financed think tank.
The authors suggested several courses of action for the United States, including integrating climate change planning into national security and defense strategies, taking a stronger role in international efforts to curb climate change, and helping less developed countries develop strategies to deal with the effects of climate change.
A Looming Disaster
Global warming author Mark Lynas, who recently travelled around the world witnessing the impact of climate change, said the findings must be a wake up call for politicians and citizens alike. He said: "This is a global emergency. We are heading for disaster and yet the world is on fossil fuel autopilot. There needs to be an immediate phase-out of coal, oil and gas and a phase in of clean energy sources. People can no longer ignore this looming catastrophe."