Tiempo Climate Newswatch

The Environmental Protection Agency (EPA) has ruled that "greenhouse gases contribute to air pollution... The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act." The landmark decision,which follows a Supreme Court ruling in April 2007 that confirmed that greenhouses gases should be regulated as a pollutant under the Clean Air Act, sets in motion a process that could ultimately force states to cut their emissions. The ruling covers not only carbon dioxide but also methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride.

Stakeholder input is to be conducted before any new regulations are brought in under the Clean Air Act. The EPA notes, though, that "notwithstanding this required regulatory process, both President Obama and Administrator Jackson have repeatedly indicated their preference for comprehensive legislation to address this issue and create the framework for a clean energy economy." "The science is screaming at us," responded Senator John Kerry, "and it’s time for Congress to act. I applaud the EPA for conducting an open, comprehensive review of these critical environmental issues and look forward to working with my colleagues and the administration to enact a strong response to one of the most serious threats facing our nation and the world."

The Global Climate Coalition (GCC) continued to claim that climate change science was not well-founded, despite advice from its expert advisers during the mid-1990s that the science could not be refuted, according to a report released during a federal lawsuit.

"The contrarian theories raise interesting questions about our total understanding of climate processes, but they do not offer convincing arguments against the conventional model of greenhouse gas emission-induced climate change," the advisers concluded. According to the minutes of a GCC committee meeting, the report, which was never made public, was approved only after the section that countered contrarian arguments was dropped. In fact, the Coalition "didn’t have to win the argument to succeed," George Monbiot, environmental writer, commented, "only to cause as much confusion as possible."

The flow of the world's largest rivers has declined over the past 50 years, according to a new study by researchers at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, in the United States. The reduction in flow into the Pacific Ocean was equivalent to turning off the Mississippi River (though the flow of that river did, in fact, increase by 22 per cent). "Reduced runoff is increasing the pressure on freshwater resources in much of the world, especially with more demand for water as population increases," reported study author Aiguo Dai from NCAR.

The rate at which China's vegetation is soaking up its carbon emissions has fallen in recent years, reports a team of scientists from Peking University led by Shilong Piao. During the final two decades of the 20th century, increased summer rains, efforts to plant forests, increased vegetation growth resulting from an expansion of shrubland, shifts in crop use and higher bamboo mass offset between 28 and 37 per cent of industrial emissions. However, the offset percentage dropped to 10 to 15 per cent in 2007, largely because of rapid economic growth.