No certainty yet, but new climate models may shed some light
By Summit Voice
FRISCO — Climate scientists and weather experts are edging ever-closer to linking between more frequent extreme weather events and global warming. In a mid-month bulletin, the World Meteorological Organization focused on persistent flooding in the UK and extreme cold weather in the Eastern U.S.The organization also pointed out that some southern hemisphere land areas were near record warm during the first several weeks of 2014.Top U.S. officials are drawing their own conclusions, including President Obama’s Science and Technology Advisor, Dr. John Holdren:
“If you’ve been hearing that extreme cold spells disprove global warming, don’t believe it. No single weather episode can prove or disprove global climate change. Climate is the pattern of weather geographically and over seasons. A growing body of evidence suggests that the kind of extreme cold experienced by the United States is a pattern we can expect to see with increasing frequency as global warming continues.
“I believe the odds are that we can expect as a result of global warming to see more of this pattern of extreme cold in the mid latitudes and some extreme warm in the far north.”
While scientists are still hesitant to draw a direct line from global warming to specific weather events, global patterns suggest that changes in the jet stream may be driving a trend more more extremes.
And soon, climate models may be able to offer a more definitive answer, according to the UK Met Office:
“As yet, there is no definitive answer on the possible contribution of climate change to the recent storminess, rainfall amounts and the consequent flooding. This is in part due to the highly variable nature of UK weather and climate.
Nevertheless, recent studies have suggested an increase in the intensity of Atlantic storms that take a more southerly track, typical of this winter’s extreme weather. There is also an increasing body of evidence that shows that extreme daily rainfall rates are becoming more intense, and that the rate of increase is consistent with what is expected from the fundamental physics of a warming world.
More research is urgently needed to deliver robust detection of changes in storminess and daily/hourly rain rates and this is an area of active research in the Met Office. The attribution of these changes to anthropogenic global warming requires climate models of sufficient resolution to capture storms and their associated rainfall. Such models are now becoming available and should be deployed as soon as possible to provide a solid evidence base for future investments in flood and coastal defences.”
For the second year in a row, parts of Australia experienced record heat, especially in terms of sustained high temperatures across Victoria, Tasmania , southern New South Wales away from the coast, and the southern half of South Australia.
A number of site records were set during the summer, including:
- Melbourne had seven 40 degree Celsius days; annual average is one day,
- Adelaide had 11 days of 42 degree Celsius days or above; annual average is one day,
- Canberra had 19 days of 35 degrees Celsius or above; annual average is 5.4 days.