ScienceDaily (Aug. 17, 2011) — A growing body of recent research indicates that, in Earth's warming climate, there is no "tipping point," or threshold warm temperature, beyond which polar sea ice cannot recover if temperatures come back down. New University of Washington research indicates that even if Earth warmed enough to melt all polar sea ice, the ice could recover if the planet cooled again.
In recent years scientists have closely monitored the shrinking area of the Arctic covered by sea ice in warmer summer months, a development that has created new shipping lanes but also raised concerns about humans living in the region and the survival of species such as polar bears.
In the new research, scientists used one of two com
puter-generated global climate models that accurately reflect the rate of sea-ice loss under current climate conditions, a model so sensitive to warming that it projects the complete loss of September Arctic sea ice by the middle of this century.
However, the model takes several more centuries of warming to completely lose winter sea ice, and doing so required carbon dioxide levels to be gradually raised to a level nearly nine times greater than today. When the model's carbon dioxide levels th
en were gradually reduced, temperatures slowly came down and the sea ice eventually returned.
"We expected the sea ice to be completely gone in winter at four times the current level of carbon dioxide but we had to raise it by more than eight times," said Cecilia Bitz, a UW associate professor of atmospheric sciences.
"All that carbon dioxide made a very, very warm planet. It was about 6 degrees Celsius (11 degrees Fahrenheit) warmer than it is now, which caused the Arctic to be completely free of sea ice in winter."
Global warming is due mostly to the atmospheric buildup of greenhouse gases, leading to an altered climate in most regions of the planet, with significant environmental, social and economic.
"What is happening here is much more serious than you think. The civilization of the twentieth century managed to impact the biosphere so that today we are on the verge of being unable to return, which would represent the loss of many species and the modification irreversible physical and chemical conditions of the planet, "said Manuel Guzman Hennessey, a researcher and professor of the department of climate change at the University of Rosario.
The ocean temperature increases more each day, which is causing the poles to thaw and raise the sea level. If this rise 6 meters, places like Florida, San Francisco, the Netherlands, Beijing, Shanghai, Calcutta and Bangladesh, among others, disappear.
Given the geographic position of Colombia and the population living in informal places near the sea, the country is vulnerable to climate change: potential hurricanes, changes in crops and foods and changes in land by drought andHeavy rains are problems they will face as a result of global warming, said Guzman.
For the expert, the earth's average temperature should not increase over the next hundred years 2 degrees Celsius. "We are currently in 0.7, but if they exceed 2 degrees, sea level could rise between 2 and 5 meters, which involves the flooding of many coastal cities like Cartagena, San Andrés, Buenaventura and Tumaco."
In order to check the roots of this problem from approaches to development in industrialized countries, the changing trends of harmonization between development, consumerism and the environment and climate change scenarios with which today's society, Universidad del Rosariodo a diploma course on global climate change, adaptation and mitigation, 18 May to 31 August.
This course will cover the most relevant aspects included in the first two parts of the fourth report of the Intergovernmental Panel on Climate Change (UN IPCC) on the latest progress made by climate models to regional and global scale and pose, from the scientific evidence, the opportunities of the clean development mechanism and actions of society around the carbon neutral trend, along with the main impacts of climate change could result in Colombia.
Hennessey Guzman, who also advises governments and organizations on issues of global warming, said the degree will adopt policies to prevent companies from making them involved in the subject and aware of the problem."The important thing is that everyone from your discipline, your job, your home can do something," he said.
IN COLOMBIA:
The excavations are taking place near the forest reserve that supplies water tothe port city ofBuenaventura. The community organization based in the village, Fundación San Cipriano says he will not allow the entry of miners to destroy thisprotected area from which they derive their livelihood through ecotourism.
SURVEY:
Dwellings Surveyed 1157
Family:
Number of members: 5439 Over 16 years: 773 Minor: 1666
Many work: 2329 many studies: 1290
If they work, specify what type of work: agricultural workers, construction workers, teachers, nurses, services, and others.
Wages and other income: 449 342.00
Remittances in MN 106 000.00
Total monthly income: $ 555 USD 342.00 213.68 MN 22 dollars.
Remittance family: 53 families.
Family Remittances: U.S. 5 300.00 approx. = 4 240.00 CUC
