ICE SEA AND GLOBAL WARMING../images/Emo63.gif
Ice Sea the reason for Global Warming? The real debate over whether or not global warming is actually happening is over the means of proof. So I was very interested to read an article in the December issue of Science that put another perspective on this. The report indicated that humans are contributing more to the retreat of sea ice in the Arctic than is natural climate change. This is because scientists have placed satellite-based observations of Arctic sea ice declines into a larger context, by using a computer model on climate change. "For climate studies, you would ideally like to see hundreds of years of records, but satellite data only goes back a couple of decades," explains Claire Parkinson, a climatologist at NASA´s Goddard Space Flight Center. Satellite data between November 1978 and March 1998 reveals that the overall Arctic ice-sheet has shown a downward trend of 37,000 square kilometres a year. That means a loss of an ice chunk that exceeds a combined area of more than double the whole British Isles. While some scientists might argue that such a loss could occur naturally over time, Parkinson said results of the recent study strongly suggest that humans have played a large role in this decline. To get a broader look, the research team used a global climate model from NOAA´s Geophysical Fluid Dynamics Laboratory at Princeton University to see how unusual that trend might be in the context of 5,000 years. "The model simulates what is going on in the ocean, atmosphere and land surface processes," Parkinson said. Data from the model reveals that the likelihood of such a decline was less than two percent over the past 5,000 years, strongly suggesting that mother nature is not the one to blame. The team also examined outputs from computer simulations that include greenhouse gas increases, tending to warm the atmosphere, and aerosol increases, tending to cool the atmosphere. The model results that included these human-induced changes show atmospheric temperature increases and a much better match with the observed sea ice decreases than the model results simulating natural variability. This suggests that the Arctic Sea ice decreases could partially be in response to increasing greenhouse gas levels during the second half of the 20th century. Certainly these results are very worrying as a reduction in the ice sheet will contribute to sea level rise which is going to have a serious effect on low lying cou
Ice Sea the reason for Global Warming? The real debate over whether or not global warming is actually happening is over the means of proof. So I was very interested to read an article in the December issue of Science that put another perspective on this. The report indicated that humans are contributing more to the retreat of sea ice in the Arctic than is natural climate change. This is because scientists have placed satellite-based observations of Arctic sea ice declines into a larger context, by using a computer model on climate change. "For climate studies, you would ideally like to see hundreds of years of records, but satellite data only goes back a couple of decades," explains Claire Parkinson, a climatologist at NASA´s Goddard Space Flight Center. Satellite data between November 1978 and March 1998 reveals that the overall Arctic ice-sheet has shown a downward trend of 37,000 square kilometres a year. That means a loss of an ice chunk that exceeds a combined area of more than double the whole British Isles. While some scientists might argue that such a loss could occur naturally over time, Parkinson said results of the recent study strongly suggest that humans have played a large role in this decline. To get a broader look, the research team used a global climate model from NOAA´s Geophysical Fluid Dynamics Laboratory at Princeton University to see how unusual that trend might be in the context of 5,000 years. "The model simulates what is going on in the ocean, atmosphere and land surface processes," Parkinson said. Data from the model reveals that the likelihood of such a decline was less than two percent over the past 5,000 years, strongly suggesting that mother nature is not the one to blame. The team also examined outputs from computer simulations that include greenhouse gas increases, tending to warm the atmosphere, and aerosol increases, tending to cool the atmosphere. The model results that included these human-induced changes show atmospheric temperature increases and a much better match with the observed sea ice decreases than the model results simulating natural variability. This suggests that the Arctic Sea ice decreases could partially be in response to increasing greenhouse gas levels during the second half of the 20th century. Certainly these results are very worrying as a reduction in the ice sheet will contribute to sea level rise which is going to have a serious effect on low lying cou