tagged w/ Coastal Areas
The ancient reserves of methane gas seeping from the melting Arctic ice cap told Jeff Chanton and fellow researchers what they already knew: As the permafrost thaws, there is a release of methane, a powerful greenhouse gas that causes climate warming.
The trick was figuring out how much, said Chanton, the John W. Winchester Professor of Oceanography at Florida State University.
The four-member team -- whose findings were published in the journal Nature Geoscience -- documented a large number of gas seep sites in the Arctic where permafrost is thawing and glaciers receding (they found 77 previously undocumented seep sites, comprising 150,000 vents to the atmosphere). Until recently, the cryosphere (frozen soil and ice) has served to plug or block these vents. But thawing conditions have allowed the conduits to open, and deep geologic methane now escapes.
The team studied the link between natural gas seepage and the melting ice cap, using aerial photos and field data to figure out the number -- and location -- of seep holes.
So, here's the rub: The more the ice cap melts, the more methane is released into the atmosphere -- and the more the climate warms.
Why should this matter to you?
People who live in coastal areas could be directly affected, said Chanton, who analyzed the methane and dated it to more than 40,000 years old.
All this seeping methane causes more melting ice, Chanton said, which causes sea levels to rise and could affect coastal real estate values -- sooner rather than later.
Possibly over the next 50 to 100 years, Chanton said.
"Methane is a very strong greenhouse gas that's grown three times faster than carbon dioxide since the industrial era," Chanton said. "As the Arctic warms, the ice caps melt and the fissures open, so methane escapes and causes more warming."
This phenomenon causes sea levels to rise, which is particularly problematic in Florida: "Along the flat Florida coastline, a 1-foot rise in sea level could cause anywhere from 10 to 100 feet of shoreline retreat -- erosion," Chanton said. "For us here in Florida, this is really important because we can expect the coast to recede."
That beach house, he warned, might be in peril: "It may not be there for your grandchildren."The ancient reserves of methane gas seeping from the melting Arctic ice cap told Jeff... more
A WARNING has been issued to New Zealand’s coastal centres, including Gisborne, that life in these places is going to be more troublesome because of a confirmed increase in extreme weather events, and other climate change impacts.
The warning comes from Dr David Wratt, the director of the Niwa’s National Climate Change Centre, who was one of a number of New Zealand scientists involved in a special report released by the world climate body, the Intergovernmental Panel on Climate Change (IPCC).
Other New Zealanders on the report team were Professor Glenn McGregor of Auckland University and Associate Professor John Camobell of Waikato University.
Dr Wratt, who is also chief scientist at the Niwa’s Climate Centre, says the IPCC report concludes that climate change is leading to an increase in the frequency, intensity and duration of extreme weather and climate events.
He says the IPCC report used observations gathered since the 1950s, and concludes there has been a decrease in the number of cold days and nights globally and an overall increase in the number of warm days and nights.
The report says trends for this century indicate more warm, and fewer cold daily temperature extremes around the globe.
Dr Wratt says there is 90-100 percent confidence that there will be an increase in the frequency of heavy precipitation events throughout the 21st century over many areas of the globe, and mean wind speeds in tropical cyclones will increase.
“We have high confidence that extreme events will have greater impacts on sectors directly reliant on weather and climate,” says Dr Wratt.
“New Zealand’s agriculture, horticulture and energy sectors clearly fall into that category.
“The high likelihood of increasingly severe extreme sea levels events is also significant, given that 12 of New Zealand’s 15 largest towns and cities are located on the coast.”
Dr Wratt says the challenge for policymakers is to develop strategies to reduce the vulnerability and exposure of people and assets to climate change extremes.
“That way, extreme weather and climate events won’t necessarily become disasters.”
The IPCC report and Dr Wratt’s remarks are backed by a study by Princeton University, just published in the Journal of Climate.
The Princeton researchers have undertaken the first major study to concentrate on variations in daily weather conditions rather than monthly or yearly averages.
The study found that day-to-day weather has grown increasingly erratic and extreme, with significant fluctations in sunshine and rainfall affecting more than a third of the planet.
The team found that extremely sunny or cloudy days have become more common than in the 1980s and that swings from thunderstorms to dry conditions have also risen considerably.
Regions such as equatorial Africa and Asia have experienced the greatest increase in the frequency of extreme conditions, with erratic shifts in the weather throughout the year.
More at the linkA WARNING has been issued to New Zealand’s coastal centres, including Gisborne,... more