Tiempo Climate Newswatch

World Heritage sites such as the Great Barrier Reef, Kilimanjaro National Park and the Tower of London will be at risk as a result of climate change, according to a new report from the United Nations Educational, Scientific and Cultural Organization (UNESCO). The publication follows the decision by the World Heritage Committee in 2005, after rejecting calls to list Mount Everest, to study the potential impact of climate change on World Heritage sites.

The report covers the impact of climate change on glaciers, marine biodiversity, terrestrial biodiversity, archaeological sites, and historic cities and settlements. The melting of glaciers is affecting the aesthetic value of sites of outstanding beauty and destroying habitats, such as that of the snow leopard in the Sagarmatha National Park, Nepal. Archaeological sites, such as the Chan Chan Archaeological Zone in Peru, are also at risk as climate change threatens to eradicate evidence of the past. "The international community now widely agrees that climate change will constitute one of the major challenges of the 21st century," says UNESCO director-general, Koïchiro Matsuura. He calls for "an integrated approach to issues of environmental preservation and sustainable development."

The International Energy Authority (IEA) predicts that China will shortly overtake the United States as the world's greatest greenhouse gas producer. "Either this year or next year," according to IEA's Fatih Birol. While China is commissioning a coal-fired plant every four days, per capita emissions remain low. The Chinese government is said to oppose emissions caps during the current phase of modernization, but would limit emissions growth.

The United States continues to stress the importance of the involvement of China and other developing countries in any future climate regime. "There will be no comprehensive global warming legislation coming out of the United States... that does not include limits or a programme for China, India and the rest of the developing world," warns C Boyden Gray, United States ambassador to the European Union, recently. "Rather than shooting at each other, the United States and Europe should be joining forces to engage China," he said ahead of a United States-European Union summit.

Global warming has caused economic losses of around US$5 billion a year over the past two decades, say researchers at the Carnegie Institution and the Lawrence Livermore National Laboratory (LLNL) in the United States. "Most people tend to think of climate change as something that will impact the future," said Chris Field at the Carnegie Institute's Department of Global Ecology in Stanford, California. "But this study shows that warming over the past two decades has already had real effects on global food supply." Over the twenty years to 2002, warming reduced the combined production of wheat, corn and barley by 40 million metric tons a year.

The researchers found that, on average, global yields responded negatively to higher temperatures, with yields dropping by three to five per cent for every degree Fahrenheit rise. Some agriculturalists were not convinced. "That kind of flies in the face of reality," said Terry Francl, an economist with the American Farm Bureau Federation. "The reality is we've had improved trends in yields during all of that time. It's hard to see how you would calculate global warming's effect on that." The researchers did say that, overall, the long-term climate trend had been offset by production gains from improved crops and better farming techniques. "A key to moving forward is how well cropping systems can adapt to a warmer world. Investments in this area could potentially save billions of dollars and millions of lives," comments David Lobell at LLNL in California.