Extreme weather events evidence of global warming, research suggests
Research shows the recent extreme weather events match research made by scientists at the IPCC regarding the effects of climate change.
An organisation of meteorologists from 189 countries around the world have announced that the recent sequence of extreme and unprecedented weather events matches predictions made by scientists regarding the environmental repercussions of global warming.
Over the past months the world has witnessed devastating floods in Pakistan, fires across Russia and the appearance of a huge 100 sq mile iceberg in Greenland.
In a statement on August 11th, the World Meteorological Organisation (WMO) said, "Several diverse extreme weather events are occurring concurrently around the world, giving rise to an unprecedented loss of human life and property. They include the record heat wave and wildfires in the Russian Federation, monsoonal flooding in Pakistan, rain-induced landslides in China, and calving of a large iceberg from the Greenland ice sheet."
The WMO is a specialised agency of the UN and concerns itself solely with the state and behaviour of the Earth's atmosphere, its varying climate and resulting distribution of water resources.
The organisation also mentioned recent droughts and fires in Australia and record temperatures in the US in the statement which saw current extreme weather conditions matching predictions made by the Intergovernmental Panel on Climate Change (IPCC)
"The occurrence of all these events at almost the same time raises questions about their possible linkages to the predicted increase in intensity and frequency of extreme events, for example, as stipulated in the Intergovernmental Panel on Climate Change's Fourth Assessment Report published in 2007."
In the report, the IPCC analysed existing weather conditions and warned that both the frequency and intensity of extreme weather events were likely to increase as the Earth's climate continues to rise in temperature.
The WMO continued, "While a longer time range is required to establish whether an individual event is attributable to climate change, the sequence of current events matches IPCC projections."
It has been suggested that events such as those in Pakistan and Russia can be attributed to a large scale pattern of atmospheric circulation. Rossby waves – movements of air towards and away from the poles – exist in the upper atmosphere. While generally kinetic, these waves can also sit still and trap weather beneath them.
Such a stagnant period has resulted in areas of low pressure over western and central Europe, high pressure over Russia and more lows further east.
In Pakistan, the low pressure has produced serious flooding which has so far killed an estimated 1,600 people and affected some 40 million more.
China is also experiencing heavy rain and floods. On August 7th a mudslide in the Gansu province claimed some 700 lives - more than 1,000 people remain missing and 12 million people are reported to have lost their homes.
The high pressure over Russia has made it difficult for clouds, and consequently rain, to fall. As a result record high temperatures have been recorded which, according to Russia's Federal Service for Hydrometeorology and Environmental Monitoring, have not been experienced since the 10th and 11th centuries, over 1,000 years ago. While the WMO admitted that climate extremes have always existed, it warned the occurrences were growing in strength, "all the events cited above compare with, or exceed in intensity, duration or geographical extent, the previous largest historical events."
Author: Tom Watts | Climate Action
Images: The US Army | Flickr