Flooding forced millions of Pakistanis to flee their homes in 2010, with July rainfall 70% above normal levels and August levels more than 100% higher than normal. In 2011 the situation has only worsened. A new report by the U.N. Intergovernmental Panel for Climate Change (IPCC) is saying that the frequency and intensity of extreme weather events around the globe - such as floods - is linked to human-made climate change.
Credit: NASA Earth Observatory
PARIS: The frequency and intensity of extreme weather events has been boosted by human induced climate change, and will likely multiply in future, a new U.N. report concludes.
The draft document, which has been three years in the making, says the severity of the impacts vary, with some regions more vulnerable than others. However, it points to a spectrum of weather events that have been affected, such as floods, heat waves, bush fires and cyclones.
Hundreds of scientists working under the Intergovernmental Panel for Climate Change (IPCC) will vet the phonebook-sized draft at a meeting in Kampala, Uganda, where members of the 194-nation body will gather later this month.
"This is the largest effort that has ever been made to assess how extremes are changing," said environmental scientist Neville Nicholls from Monash University in Melbourne, Australia, who was a coordinating lead author of one of the review's key chapters.
Future weather volatility
The report's authors stress that the level of "confidence" in the findings depends on the quantity and quality of data available.
But the overall picture that emerges is one of enhanced volatility and frequency of dangerous weather, leading in turn to a heightened risk for large swathes of humanity in coming decades.
A series of natural catastrophes around the world has boosted the need to determine whether such events are freaks of the weather or part of a long-term shift in climate. A summary of the report was made available, with further revisions expected before its release on 18 November.
Floods, fires, hurricanes and heat waves
In 2010, record temperatures fuelled devastating forest fires across Siberia, while Pakistan and India reeled from unprecedented flooding.
This year, the United States has suffered a record number of billion-dollar disasters from flooding in the Mississippi and Missouri Rivers, to Hurricane Irene to a severe drought in Texas. China is reeling from lack of water too, and central America and Thailand continue to have mounting death tolls from recent flooding.
These events match predicted impacts of global climate change, which has raised temperatures, increased the amount of water in the atmosphere and warmed ocean surface temperatures - all drivers of extreme weather. But dissecting the role of natural fluctuations in the weather and rising levels of greenhouse gases in the atmosphere has proven devilishly difficult.
The predictable weather
The predictable weather trends of the next several decades will be increasing the unpredictability of week to week weather, predictably. I feel like I'm being trolled.