Scientific and observational data from Antarctica are driving home the message that we have entered a period of consequences. Most recently, scientists have discovered ice streams hiding bigger reservoirs of water in West Antarctica. The evidence has "major implications for glacial melt rates and associated sea-level rises" and the rate of warming. Equally frightening is that the ice streams feed into the Ross Ice Shelf, a major southern ice shelf whose melting would indicate "the end of the road" according to one scientist. In 1999, scientists began to observe pools of water on top of the Larsen Ice Shelf (green …

Australian Prime Minister John Howard is in a sticky, yet dry, situation. Even though a drought has caused Australia's agricultural production to fall 25 percent in the last year, Howard may have to ban irrigation so that urban centers can have drinking water. The targeted river basin, the Murray-Darling, is known as Australia's "food bowl" because it houses 72 percent of Australia's farm and pasture land. If insufficient rain continues through the next few weeks, this year's harvest will be devastated and cities will need to implement water usage restrictions. Prime Minister Howard doesn't accept the connection to global warming, …

The IPCC reports are some of the most highly anticipated of 2007. An obvious sign? Within two weeks of one report's release, papers are already covering a leak from the next. IPCC Working Group III's focus is on mitigation, meaning a fair number of policy implications can be derived from its conclusions. So here's a hint for America's auto industry: the report calls for urgent action on road pollution. In the United States, there are 483 passenger cars per 1,000 people (EarthTrends). The world average is about 100, and few countries outnumber our car count (Australia, for example, had 492 …

(Continued from parts I and II.) Last but not least (actually, what quite literally hits closest to home!): North America Moderate climate change in the early decades of the century is projected to increase aggregate yields of rain-fed agriculture by 5-20 percent, but with important variability among regions. Warming in Western mountains is projected to cause decreased snowpack, more winter flooding, and reduced summer flows, exacerbating competition for over-allocated water resources. Disturbances from pests, diseases, and fire are projected to have increasing impacts on forests, with an extended period of high fire risk and large increases in area burned. Cities …

And now for the IPCC report's regional assessments, continued from yesterday: Africa By 2020, between 75 and 250 million people are projected to be exposed to an increase of water stress due to climate change. The area suitable for agriculture, the length of growing seasons, and yield potential, particularly along the margins of semi-arid and arid areas, are expected to decrease. This would further adversely affect food security and exacerbate malnutrition in the continent. In some countries, yields from rain-fed agriculture could be reduced by up to 50 percent by 2020. Toward the end of the 21st century, projected sea-level …

The summary for policymakers (PDF) of the report by the IPCC Second Working Group is out! A summary of the summary: Where does the information come from? The IPCC, WGI's 4AR on the Scientific Basis of climate change. 29,000 observational data series crossed with expected changes to physical and biological systems based on those observations, with 89% consistency between the two. Models, some of which account for non-anthropogenic sources of warming (solar and volcanic activity) and others that do not. The results show that, "models with combined natural and anthropogenic forcings simulate observed responses significantly better than models with natural …

Bring your tissue to this one. On Friday, the IPCC publicizes its "emotional heart," the Second Working Group's contribution to the Fourth Assessment Report, covering impacts, adaptation, and vulnerability. Preliminary drafts have been leaked. Why is it shaping up to be such a tear-jerker? According to Andrew Weaver, a lead author of Working Group I and climate scientist at the University of Victoria in British Columbia, this one illustrates "a highway to extinction, but on this highway there are many turnoffs. This is showing you where the road is heading. The road is heading toward extinction." As many as one-third …

In November, the issue of EPA's refusal to regulate greenhouse gas emissions went before the Supreme Court. Yesterday, the decision (PDF) was announced -- 5-4 in favor of Massachusetts, meaning that the EPA does have the authority and responsibility to regulate carbon dioxide as a pollutant. In short, the time to act is now! In the chutzpah department, EPA actually tried to argue that 1) "any EPA regulation of motor-vehicle emission" was a "piecemeal approach to climate change that would conflict with the President's comprehensive [!] approach" -- comprehensive, I suppose, in the sense that he refuses to take any …

How high and fast will sea levels rise? An important piece (PDF) by Stefan Rahmstorf in Science concludes: A rise of over 1 m by 2100 for strong warming scenarios cannot be ruled out, because all that such a rise would require is that the linear relation of the rate of sea-level rise and temperature, which was found to be valid in the 20th century, remains valid in the 21st century. These scenarios, which are really nothing more than business-as-usual emissions plus amplifying carbon-cycle feedbacks, would give us sea level rising at 6 inches a decade in 2100. In such …

At the Environment and Public Works hearing yesterday, Sen. Inhofe (R-Okla.) displayed an amazing lack of understanding about energy as he tried to get Gore to make a meaningless pledge. Now the EPW Minority web page repeats the inane charge: Former Vice President Al Gore refused to take a "Personal Energy Ethics Pledge" today to consume no more energy than the average American household. But why should Gore take such a pledge? Gore is a champion of greenhouse gas reductions, not energy reductions. Gore explained he buys 100 percent renewable power and is planning to build a solar power system. …