Tags: global warming, deforestationMBendi Newsletter: 28.Nov.2008
In our last newsletter, we commented on the energy implications of the International Energy Agency's World Energy Outlook 2008. The outlook also had much to say about the likely environmental impact of their reference scenario, so I dug through our Signposts for the past three months to see what new evidence there is for climate change. Here's a summary of what I found.
First some new forecasts to set the scene. Ice sheets on Antarctica and Greenland would raise world sea levels by about 70 meters if they melted completely. Fortunately, the UN Climate Panel projects that sea levels will only rise by between 18 and 59 cm this century. Scientists in Japan forecast that peatlands, concentrated in high latitude locations including Canada, Russia and Alaska, could experience a 40% carbon loss from shallow peat and 86% carbon loss from deep peat with a warming of four degrees C.
The IEA reference scenario forecasts that world greenhouse gas emissions, including non-energy CO2 and all other gases, will grow 35% between 2005 and 2030, leading to a doubling in the concentration of those gases in the atmosphere by the end of this century and an eventual global average temperature increase of up to 6°C on today. Separately, the Scripps Institution of Oceanography warned that the earth will warm about 2.4° C above pre-industrial levels even under extremely conservative greenhouse-gas emission scenarios and under the assumption that efforts to clean up particulate pollution continue to be successful.
So, where are we right now? Starting with the atmosphere above us, the UN Climate Change Secretariat reported that emissions by 40 industrialized nations dropped 0.1% from 2005 to 2006 driven by a fall in U.S. emissions. However, 2006 emissions of 18.0 billion tonnes of carbon dioxide were still 2.3% up from 17.6 billion in 2000 and only 4.7% down from 1990 levels of 18.9 billion tonnes. Most of this drop is due to the 1991 collapse of the Soviet Union, whose emissions have risen 7.4% to 3.7 billion tonnes just since 2000.
The Global Carbon Project reported anthropogenic CO2 emissions have been growing about four times faster since 2000 than during the previous decade. Worldwide man-made emissions of CO2 increased 3% in 2007. The annual mean growth rate of atmospheric CO2 was 2.2 ppm per year in 2007, above the 2.0 ppm average for the period 2000-2007 and 50% above the average annual mean growth rate for the previous 20 years of 1.5 ppm. Atmospheric CO2 concentration was 383 ppm in 2007, 37% above the concentration at the start of the industrial revolution and the highest during the last 650,000 years and probably during the last 20 million years. Natural land and ocean CO2 sinks removed 54% of all CO2 emitted from human activities during the period 2000-2007.
In 2006, China passed the USA, still the leader in emissions per-capita, to become the largest CO2 emitter, and India will soon overtake Russia to become the third largest emitter. More than half of the global emissions come from less developed countries. However, developing countries with 80% of the world's population still account for only 20% of the cumulative emissions since 1751; the poorest countries in the world, with 800 million people, have contributed less than 1% of these cumulative emissions. Japan reported 2007 emissions were at record levels due to closure of a nuclear power plant.
An MIT report in Geophysical Research Letters indicated that levels of methane, a greenhouse gas 25 times as potent as carbon dioxide, rose abruptly in Earth's atmosphere in 2007. Methane has more than doubled in the atmosphere since pre-industrial times, but stayed largely stable over the last decade or so before rising in 2007 simultaneously at all the places scientists measured around the globe.
Moving from the air to the oceans, an Australian study showed rising carbon dioxide levels in the world's oceans due to climate change, combined with rising sea temperatures, could accelerate coral bleaching, destroying some reefs before 2050. Scientists reported that the number of polluted "dead zones" areas of oxygen-starved water in the world's oceans is growing at about 5% per annum and coastal fish stocks are more vulnerable to collapse than previously feared. According to the Mediterranean Institute for Advanced Studies in Spain marine organisms are more vulnerable to low oxygen content than currently recognized, with fish and crustaceans being the most vulnerable.
The Center for Australian Weather and Climate Research reported in Nature Geoscience that the Southern Ocean, the world's largest carbon sink, has maintained its ability to soak up excess carbon despite changes to currents and wind speeds. The ocean was becoming warmer and less saline. Currents had not changed in strength, though they had shifted closer to Antarctica. CO2 is absorbed by the ocean's turbulent surface layer and then carried to the depths by circulation patterns. It is also absorbed by phytoplankton and other organisms, which fall to the ocean bottom when they die. Some of the carbon-rich water from the depths rises near Antarctica, releasing CO2, while further away from the continent, it sinks again because it is less dense. Overall the ocean absorbs much more than it releases.
Scientists calculated temperatures had risen about 2 Celsius in the past 40 years in the Arctic and by a few tenths of a degree in Antarctica, where some winter sea ice has even expanded in recent decades. The University of Colorado's National Snow and Ice Data Center reported that Arctic sea ice melted to its second-lowest level in the summer of 2008, 34% percent below the average from 1979 to 2000, but 9% above the record low set in 2007, the warmest year on record in the Arctic. The annual report of the U.S. National Oceanic and Atmospheric Administration concluded that autumn air temperatures in the Arctic had climbed to a record 5 degrees C due to major losses of sea ice caused by a warming trend dating back decades. Wild reindeer and caribou herds appear to be declining in numbers. Surface ice is also melting in Greenland.
However, in line with the adage that every dark cloud has a silver lining, the UN Environment Programme reported that a 3 km thick cloud of pollutants hanging over Asia may be delaying the worst effects of global warming. And the Earth Policy Institute published figures showing that while the number of cars and bicycles manufactured during the 1950's and 1960's was almost the same, nearly three times as many bicycles were manufactured as cars in 2007 and bicycle sales continue to rise even while car sales plummet.
I recently read John Firor's The Changing Atmosphere, which succinctly describes the phenomena of acid rain, stratospheric ozone and climate heating. Long before the end, one feels he is describing a situation that calls for immediate action - I was horrified to find the book was researched and published all of twenty years ago and, apart from getting rid of CFCs, we haven't made a lot of progress since then. However, we're heartened that the new US government plans to comprehend the environment in its proposed economic rescue package. They could well take a leaf out of the book of Portugal, which aims to have 60% of electric power provided by solar, wind, wave and other clean sources by 2020 and which last week signed an agreement with Renault and Nissan to create a national network for zero-emission cars by the end of 2011. Now that's what Detroit should be proposing to Congress is exchange for a bail-out...
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