Climate - Nov 29
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Climate 'altering UK marine life'
The biodiversity and productivity of seas around the UK could already be suffering the consequences of climate change, a report has concluded.
It says damaging storms have become more frequent, and rising sea surface temperatures have led to an apparent northward shift of warm-water plankton.
The "Annual Report Card" pulls together leading research on climate change's impact on the UK's marine environment. The study was compiled by the Marine Climate Change Impacts Partnership.
(29 Nov 2006)
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Carbon Emissions Show Sharp Rise
Richard Black, BBC via Common Dreams
The rise in humanity's emissions of carbon dioxide has accelerated sharply, according to a new analysis.
The Global Carbon Project says that emissions were rising by less than 1% annually up to the year 2000, but are now rising at 2.5% per year.
It says the acceleration comes mainly from a rise in charcoal consumption and a lack of new energy efficiency gains.
The global research network released its latest analysis at a scientific meeting in Australia.
Dr Mike Rapauch of the Australian government's research organisation CSIRO, who co-chairs the Global Carbon Project, told delegates that 7.9 billion tonnes (gigatonnes, Gt) of carbon passed into the atmosphere last year. In 2000, the figure was 6.8Gt.
"From 2000 to 2005, the growth rate of carbon dioxide emissions was more than 2.5% per year, whereas in the 1990s it was less than 1% per year," he said.
The finding parallels figures released earlier this month by the World Meteorological Organization showing that the rise in atmospheric concentrations of CO2 had accelerated in the last few years.
(28 Nov 2006)
Phytoplankton Cloud Dance
Atmospheric scientists have reported a new and potentially important mechanism by which chemical emissions from ocean phytoplankton may influence the formation of clouds that reflect sunlight away from our planet. This intimate connection between life and the environment of Earth could have profound implications for the future of our planet's global ecosystem.
Discovery of the new link between clouds and the biosphere grew out of efforts to explain increased cloud cover observed over an area of the Southern Ocean where a large bloom of phytoplankton was occurring. Based on satellite data, the researchers hypothesized that airborne particles produced by oxidation of the chemical isoprene which is emitted by the phytoplankton may have contributed to a doubling of cloud droplet concentrations seen over a large area of ocean off the eastern coast of South America.
Using complex numerical models, they estimated that the resulting increase in cloudiness reduced the absorption of sunlight by an amount comparable to what has been measured in highly polluted areas of the globe. If confirmed by field studies, this connection between clouds and biological activity could add a critical new component to global climate models. Many environmental scientists believe that increased cloud cover may be partially countering the effects of global warming by reducing the amount of energy the planet absorbs from the sun.
(13 Nov 2006)
High Stakes: Designing emissions pathways to reduce the risk of dangerous climate change
Dr Paul Baer with Dr Michael Mastrandrea, Institute for Public Policy Research
As increasingly alarming reports of current impacts from human-caused climate change hit the news,policymakers are paying greater attention to the challenge of setting long-term climate objectives and the short- to medium-term policies needed to achieve them. In doing so, they quite reasonably ask what policies - what stabilisation targets for atmospheric levels of greenhouse gases (GHGs) and ultimately what emissions targets - would offer assurance of avoiding intolerable impacts.
...Recent research has robustly shown that a high likelihood of keeping the long-term warming below the 2ºC threshold requires the stabilisation of the net `effective' concentration of GHGs (including the offsetting effects of aerosols, small airborne particles or droplets which reflect sunlight) below the level equivalent to 400 parts per million (ppm) of carbon dioxide (CO2) (Meinshausen 2006, Baer 2005). For reasons we discuss in the text, this net level of CO2-equivalent (CO2-e) is very likely to be exceeded in the coming
However, because of the time lag between the increase in GHG concentrations and the increase in temperature - what we call `thermal inertia' - the atmosphere need never reach the maximum level of temperature `implied' by the GHG concentration peak (the long-term temperature that would be reached if CO2-equivalent concentrations were held at that peak level indefinitely). The faster and further that GHGconcentrations can be lowered below their peak, the lower will be the peak temperature increase that is eventually reached.
(8 Nov 2006)
Black carbon major suspect in warming trend
Richard Read, The Oregonian
East Sylvan Middle School sixth-grader Jack Edwards has two dominant impressions from studying Chinese in Beijing last summer: Heat and haze. "It always felt like you were walking through a big bowl of 2 percent milk," Edwards says. "You knew the sun was there because it was really hot, but you couldn't see it."
The active ingredient in the haze is black carbon, or soot, a stew of fine particles belched from household stoves and heaters, vehicles and crop burning. China generates the largest share of these particles emitted worldwide each year, with India and the former Soviet Union not far behind.
Until recently, scientists overlooked the role of soot in global warming, concentrating on the more easily quantified gases that trap heat. But suddenly these aerosols -- such as sulfur compounds that contribute to about 400,000 premature deaths each year in China -- occupy the frontier of research on climate change.
...The effect is deceptive. Black carbon, one of the major constituents of the haze, absorbs heat a half-mile or so above the earth, contributing to global warming while shading the ground below, says Michael Bergin, a Georgia Institute of Technology researcher. "You're still putting more energy in the lower atmosphere than would have been there before," Bergin says
(24 Nov 2006)
Answers About the Earth's Energy Imbalance by James E. Hansen
Mary Tobin, Earth Institute News
What have we learned about climate forcings from the energy imbalance?
The fact that the observed and simulated rates of ocean heat storage are similar in magnitude suggests that our estimated net climate forcing is reasonably accurate. The measured energy imbalance confirms that the aerosol (fine particle) forcing is substantial and opposite in sign (cooling) to greenhouse gas forcing, but it is smaller than the positive (warming) greenhouse gas forcing. The net climate forcing now clearly is positive and will lead to additional warming. There are still substantial uncertainties about the values and trends of several climate forcings, especially aerosol effects. The good agreement that we find in simulated global temperature change may be partly coincidental as errors in some forcings cancel errors of the opposite sign in other forcings. Nevertheless, because aerosol amounts are unlikely to increase in the future, and may decrease as nations attempt to reduce particulate pollution, we can predict with considerable confidence that the net climate forcing and global warming will continue to increase.
(4 Nov 2006)
So what is it -- do aerosols heat or cool? Well it depends on what type of aerosol, and other factors. Yun Qian, researcher quoted in Richard Read's article above writes:
(1) There are two major types of aerosols: scattering one (e.g. sulfate, organic carbon) and absorbing one (e.g. soot, sometimes also called black carbon)
(2) scattering aerosol generally cool the earth since they reflect sunlight (solar radiation) back to space; absorbing aerosol may heat the atmosphere since they attract the sunlight
(3) In reality these two types aerosols are living together (mixed internally or externally) in the atmosphere.
(4) Richard Read's article focuses on soot (absorbing aerosol). Should be ok to say soot is one of warming agents.
(5) Whether the overall effect of aerosols (air pollution) is cooling or warming, depends on the region and season, also depends on what parts of earth meant (e.g. land surface, or air, and which part of air, I mean vertical level). Usually we believe that aerosolst have a overall cooling effect at global scale, at least to land surface (the absorbing aerosol can still cool the land surface even it can heat atmosphere). Please see Sulfate, bc (black carbon), oc (organic carbon) in Figure 6.6 www.grida.no/climate/ipcc_tar/wg1/245.htm#fig66
You can get some ideas on relative roles and overall impact of greenhouse gasses and various aerosols on earth radiative forcing.
(6) IPCC report is the most authoritive literature conducted by thousands of climate scientists worldwide (updated every 5 years). It's readable to general readers. I would recommend you to read this (at least Summary Part of each section) if you are interested in climate change issue. www.grida.no/climate/ipcc_tar/wg1/
Up in Smoke: The African Apocalypse
Geoffrey Lean, The Independent UK via Alternet
The continent burning into a desert Nowhere is the effect of global warming more dangerous than in Somalia, where the worst drought in 40 years is affecting the lives of 1.8 million people.
Somalia's harvest, brought in last month, is almost 30 per cent lower than normal, the result of the worst drought in at least 40 years. The UN's Food and Agriculture Organisation says nthat the situation is "alarming," with a "severe food crisis," affecting 1.8 million people, persisting throughout the country for at least the rest of the year.
Around Habiba Hassan's home no one can remember a drought this severe. Children have been dying, and the land, in her words, is "turning to desert." She has no doubt about the cause: "It's global warming." How does she know? The people of her village had learnt about it from the BBC Somali service, heard on their £2.50 radios.
Hers is just one of the African voices in a searing report on the danger that the changing climate poses to the continent, published tomorrow by 22 British environment and development charities, pressure groups and academic institutes. It shows that the world's poorest continent -- the continent least able to cope with the impact of climate change -- is the most vulnerable to its effects.
(24 Nov 2006)