Wild Weather a Taste of Things to Come
A MONSOON dropped 35 centimetres of rain in one day across many parts of South Asia this month. Germany had its wettest May on record, and April was the driest there in a century. Temperatures reached 45 degrees in Bulgaria last month and 32 degrees in Moscow in late May, shattering long-time records.
The year still has almost five months to go, but it has already experienced a range of weather extremes that the UN's World Meteorological Organisation says is well outside the historical norm and is a precursor to much greater weather variability as global warming transforms the planet.
The warming trend confirmed in February by the Intergovernmental Panel on Climate Change - based on the finding that 11 of the past 12 years had higher average ground temperatures than any others since formal temperature recording began - appears to have continued with a vengeance into 2007. The meteorological organisation reported that January and April were the warmest worldwide ever recorded.
"Climate change projections indicate it to be very likely that hot extremes, heatwaves and heavy precipitation events will continue to become more frequent," the organisation said.
The heavy rains in South Asia have resulted in more than 500 deaths and displaced 10 million people, while 13.5 million Chinese have been affected by floods, the report said. In England and Wales, the period from May to July was the wettest since record-keeping began in 1766, resulting in floods that killed nine and caused more than $US6billion ($7billion) in damage.
The World Meteorological Organisation, which is co-sponsoring a series of meetings and reports on global climate change, is putting together an early-warning system for climate extremes and establishing long-term monitoring systems, and plans to help countries most vulnerable to climate change.
"The average Northern Hemisphere temperatures during the second half of the 20th century were very likely the highest during any 50-year period in the last 500 years, and likely the highest in the past 1300 years," the report said.
Global warming is expected to result in more extreme weather because of changes in atmospheric wind patterns and the ability of warmer air to hold more moisture, said Martin Manning, the head of the Intergovernmental Panel on Climate Change's working group on the physical science of climate change. He said that one year of heavier than normal rains and warmer than usual temperatures said nothing definitive about climate change, but they were consistent with the panel's long-term predictions.
"What we have projected is an increase in extreme events as the global temperatures rise," Dr Manning said. "Floods, droughts and heatwaves are certainly consistent with that."
The World Meteorological Organisation reported the extreme weather occurred in many parts of the world. In May, a series of large waves (estimated at up to 3.6 metres) swamped almost 70 islands in 16 atolls in the Maldive Islands off south India, causing serious flooding and extensive damage. Halfway around the globe, Uruguay was hit during the same month by the worst flooding since 1959 - floods that affected more than 110,000 people and severely damaged crops and buildings. Two months later, an unusual winter brought high winds, blizzards and rare snowfall to parts of South America.
Meanwhile, two extreme heatwaves affected south-eastern Europe in June and July. Dozens of people died, and firefighters worked nonstop battling blazes that destroyed thousands of hectares. On July 23, temperatures hit the record 45 degrees in Bulgaria.
Copyright © 2007. The Sydney Morning Herald.