Hi Stephen--Not at all--I am just saying that the meteorological situation is also a very important factor to consider.
Mike On 6/5/12 6:10 AM, "Stephen Salter" <[email protected]> wrote: > Mike > > Both diffusion and oxidation are involved. Are you saying that methane > released from the Arctic does not get oxidised? > > Stephen > > Emeritus Professor of Engineering Design > Institute for Energy Systems > School of Engineering > Mayfield Road > University of Edinburgh EH9 3JL > Scotland > Tel +44 131 650 5704 > Mobile 07795 203 195 > www.see.ed.ac.uk/~shs > > > On 04/06/2012 14:46, Mike MacCracken wrote: >> Hi Stephen--I think there is a simpler explanation, and that is that the >> planetary boundary layer is shallow due to the typical inversion, so CO2 >> tends to build up near the ground during the non-growing season. My guess is >> that the late summer values also tend to be a bit lower than Mauna Loa due >> to the CO2 being pulled out from a thinner layer (you see a much larger >> seasonal variation in high latitude CO2 than at Mauna Loa). >> >> Mike >> >> >> On 6/4/12 6:30 AM, "Stephen Salter"<[email protected]> wrote: >> >>> Hi All >>> >>> There are not many large coal-fired power stations in the Arctic and so >>> the question arises about where this extra CO2 in the Arctic has come >>> from. One possibility is that it is the product of methane >>> decomposition and would be in line with the report to this group from >>> Greg Rau of 22 May. >>> >>> We know that the atmosphere weighs about 5 E18 kilograms. If we know >>> the plan area represented by the observing stations and the decay rate >>> of methane to CO2 we could get an approximate figure for the mass of >>> methane causing the rise in CO2. We could then compare this with the >>> scary rate of methane increase reported by Semiletov and Shakhova. >>> >>> Stephen >>> >>> >>> Emeritus Professor of Engineering Design >>> Institute for Energy Systems >>> School of Engineering >>> Mayfield Road >>> University of Edinburgh EH9 3JL >>> Scotland >>> Tel +44 131 650 5704 >>> Mobile 07795 203 195 >>> www.see.ed.ac.uk/~shs >>> >>> >>> On 02/06/2012 17:41, Rau, Greg wrote: >>>> Greenhouse gas levels pass symbolic 400ppm CO2 milestone >>>> Monitoring stations in the Arctic detect record levels of carbon dioxide, >>>> higher than ever above 'safe' 350ppm mark >>>> Associated Press >>>> guardian.co.uk, Friday 1 June 2012 07.50 EDT >>>> >>>> The Arctic Ocean with leads and cracks in the ice cover of north of Alaska. >>>> Photograph: Courtesy Eric Kort/Jet Propulsion Laboratory/NASA >>>> The world's air has reached what scientists call a troubling new milestone >>>> for carbon dioxide, the main global warming pollutant. >>>> >>>> Monitoring stations across the Arctic this spring are measuring more than >>>> 400 >>>> parts per million of the heat-trapping gas in the atmosphere. The number >>>> isn't quite a surprise, because it's been rising at an accelerating pace. >>>> >>>> Years ago, it passed the 350ppm mark that many scientists say is the >>>> highest >>>> safe level for carbon dioxide. It now stands globally at 395. >>>> >>>> So far, only the Arctic has reached that 400 level, but the rest of the >>>> world >>>> will follow soon. >>>> >>>> "The fact that it's 400 is significant," said Jim Butler, the global >>>> monitoring director at the National Oceanic and Atmospheric >>>> Administration's >>>> Earth System Research Lab. "It's just a reminder to everybody that we >>>> haven't >>>> fixed this, and we're still in trouble." >>>> >>>> "The news today, that some stations have measured concentrations above >>>> 400ppm >>>> in the atmosphere, is further evidence that the world's political leaders >>>> with a few honourable exceptions are failing catastrophically to address >>>> the climate crisis," former vice president Al Gore, the highest-profile >>>> campaigner against global warming, said in an email. "History will not >>>> understand or forgive them." >>>> >>>> Carbon dioxide is the chief greenhouse gas and stays in the atmosphere for >>>> 100 years. Some carbon dioxide is natural, mainly from decomposing dead >>>> plants and animals. Before the industrial age, levels were around 275 parts >>>> per million. >>>> >>>> For more than 60 years, readings have been in the 300s, except in urban >>>> areas, where levels are skewed. The burning of fossil fuels, such as coal >>>> for >>>> electricity and oil for gasoline, has caused the overwhelming bulk of the >>>> man-made increase in carbon in the air, scientists say. >>>> >>>> It's been at least 800,000 years probably more since Earth saw carbon >>>> dioxide levels in the 400s, Butler and other climate scientists said. >>>> >>>> Readings are coming in at 400 and higher all over the Arctic. They've been >>>> recorded in Alaska, Greenland, Norway, Iceland and even Mongolia. But >>>> levels >>>> change with the seasons and will drop a bit in the summer, when plants suck >>>> up carbon dioxide, NOAA scientists said. >>>> >>>> So the yearly average for those northern stations likely will be lower and >>>> so >>>> will the global number. >>>> >>>> "It's an important threshold," said the Carnegie Institution ecologist >>>> Chris >>>> Field, a scientist who helps lead the Nobel Prize-winning Intergovernmental >>>> Panel on Climate Change. "It is an indication that we're in a different >>>> world." >>>> >>>> Ronald Prinn, an atmospheric sciences professor at the Massachusetts >>>> Institute of Technology, said 400 is more a psychological milestone than a >>>> scientific one. We think in hundreds, and "we're poking our heads above >>>> 400," >>>> he said. >>>> >>>> Tans said the readings show how much the Earth's atmosphere and its climate >>>> are being affected by humans. Global carbon dioxide emissions from fossil >>>> fuels hit a record high of 34.8 billion tonnes in 2011, up 3.2%, the >>>> International Energy Agency announced last week. >>>> >>>> The agency said it's becoming unlikely that the world can achieve the >>>> European goal of limiting global warming to just 2 degrees based on >>>> increasing pollution and greenhouse gas levels. >>>> >> >> -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. 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