Scientists see climate change link to Australian floods
UPDATE: “Climate change has likely intensified the monsoon rains that have triggered record floods in Australia’s Queensland state, scientists said on Wednesday, with several months of heavy rain and storms still to come.”
Flood-weary Queensland, Australia suffered a new flooding disaster yesterday when freak rains of six inches fell in just 30 minutes near Toowoomba. The resulting flash flood killed nine people and left 59 missing. The flood waters poured into the Brisbane River, causing it to overflow, and significant flooding of low-lying areas in Brisbane, Australia’s third largest city with some 2 million people, is expected on Thursday.
Here is a stunning video of the flooding:
Remarkable 5-minute YouTube video showing the sad fate of a row of parked cars when a nearby small stream experiences a flash flood, sweeping away dozens of the cars. A note to the wise: Two minutes into the video, we see a man enter the flash flood to save his car. He is successful, but his actions were extremely risky–most flash flood deaths occur when cars with people inside get swept away. I would not have attempted to save my car in that situation.
The wise advice comes from Meteorologist Dr. Jeff Masters, who puts the flooding in context:
As I discussed last week, Australia had its wettest spring (September – November) since records began 111 years ago, with some sections of coastal Queensland receiving over 4 feet (1200 mm) of rain. Rainfall in Queensland and all of eastern Australia in December was the greatest on record, and the year 2010 was the rainiest year on record for Queensland. The ocean waters surrounding Australia were the warmest on record during 2010, and these exceptionally warm waters allowed much higher amounts of water vapor to evaporate into the atmosphere, helping fuel the heavy rains. The record warm ocean temperatures were due to a combination of global warming and the moderate to strong La Ni±a event that has been in place since July. Queensland typically has its rainiest years when La Ni±a events occur, due to the much warmer than average ocean temperatures that occur along the coast. Beginning in December, the Queensland floods have killed at least 19, and done $5 billion in damage. Queensland has an area the size of Germany and France combined.
I have also written about how the warmest sea surface temperatures on record fuel ‘biblical’ Australian floods
The Australian Bureau of Meteorology released its “Annual Australian Climate Statement 2010,” which helps explain why “” record sea surface temperatures:
Based on preliminary data (to November 30), sea surface temperatures in the Australian region during 2010 were +0.54 °C above the 1961 to 1990 average. This is the warmest value on record for the Australian region. Individual high monthly sea surface temperature records were also set during 2010 in March, April, June, September, October and November. Along with favourable hemispheric circulation associated with the 2010 La Ni±a, very warm sea surface temperatures contributed to the record rainfall and very high humidity across eastern Australia during winter and spring. The most recent decade (2001ˆ’2010) was also the warmest decade on record for sea surface temperatures following the pattern observed over land.
Dr. Kevin Trenberth, head of NCAR’s Climate Analysis Section, has explained the connection between human-caused global warming and extreme deluges: “There is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.”
John Cook of Skeptical Science, “studied physics at the University of Queensland” and lives there. He has some remarkable videos here and notes:
It’s times like this that I can’t help thinking of the words of NOAA scientist Deke Arndt, “Climate trains the boxer but weather throws the punches”. Weather will always throw these random punches at us. Occasionally it gets in a lucky punch that knocks us off our feet. But what we’re doing is training weather to throw harder punches at us and more often. That’s what is being observed and that’s what we expect to see more of in the future.
Anyone who wishes to help, you can Donate to the Queensland Government’s flood relief appeal.
The main ‘good’ news to come from all this rain, as the Bureau of Meteorology reports is,
Drought eases in the east but continues in the southwest
For some parts of the southeast 2010 was the first calendar year since 1996 to see above average rainfall. The heavy rainfall in 2010 marked a dramatic reversal of dry conditions across Queensland, New South Wales, Victoria and South Australia. Significantly, the Murray Darling Basin recorded its wettest year on record, ending a record sequence of below average rainfall years extending back to 2001. This rainfall led to a dramatic recovery in water storages across the Murray-Darling Darling Basin from 26% at the start of 2010 to 80% at the start of 2011.
From the point of view of surface water, soil moisture and annual rainfall totals; the “long dry” which commenced in late 1996 in the far southeast of mainland Australia and late 2001 across much of the Murray-Darling Basin has effectively ended.
In contrast to the rest of the continent, the southwest of Western Australia experienced a very dry year, continuing the long drying trend which extends back to the late 1960s. For the southwest region as a whole, the 2010 rainfall total was a record low 392 mm, well below the previous low of 439 mm in 1940. Rainfall in the cropping season (April to October) in southwest Western Australia also set a record with just 310 mm falling; the previous low was 348 mm in 1914.
The Big Dry is over, though there is still record drought in the SW:
The question often gets asked here, how can you say global warming causes both intense rainfall and intense drought? Cook dealt with the question this way
Q: It seems that climate scientists are suffering in the media from conflicting messages and predictions. every weather event from floods to blizzards are being blamed on global warming. a few years ago the news i heard was the global warming would cause drought, not massive rains.Cook: Global warming leads to an intensification of the water cycle. Drought severity is increasing in some regions and extreme precipitation is increasing in other regions. These are not merely predictions – an increase in drought severity and extreme precipitation have both been observed.
Australia is a big place and the most arid habited continent in the world. The South is going to be increasingly vulnerable to the predicted expansion of the subtropics. “The unexpectedly rapid expansion of the tropical belt constitutes yet another signal that climate change is occurring sooner than expected,” noted one climate researcher in December 2007. A 2008 study led by NOAA noted, “A poleward expansion of the tropics is likely to bring even drier conditions to” the U.S. Southwest, Mexico, Australia and parts of Africa and South America.”
At the same time, Queensland is obviously going to be subject to these intense floods — as are large parts of the rest of the world — because there is more water vapor over the ocean, aside from whatever long-term changes in the climate there are.
In this country, the scientific literature has already demonstrated that global warming is driving this intensification of the hydrological cycle, making droughts and deluges more extreme (see Study: Global warming is driving increased frequency of extreme wet or dry summer weather in southeast, so droughts and deluges are likely to get worse).
A new study by a Duke University-led team of climate scientists suggests that global warming is the main cause of a significant intensification in the North Atlantic Subtropical High (NASH) that in recent decades has more than doubled the frequency of abnormally wet or dry summer weather in the southeastern United States….
To forecast future trends in the NASH’s intensity, the team used climate models developed for use by the Intergovernmental Panel on Climate Change’s Fourth Assessment Report in 2007. The models – known as Coupled Model Intercomparison Project Phase 3 (CMIP3) models – predict the NASH will continue to intensify and expand as concentrations of carbon dioxide and other greenhouse gases increase in Earth’s atmosphere in coming decades.
“This intensification will further increase the likelihood of extreme summer precipitation variability – periods of drought or deluge – in southeastern states in coming decades,” Li says.
The worrisome part, as I’ve said many times, is that we’ve only warmed about a degree Fahrenheit in the past half-century. We are on track to warm nearly 10 times that this century (see M.I.T. doubles its 2095 warming projection to 10°F “” with 866 ppm and Arctic warming of 20°F ). And that’s just business as usual. The plausible worst-case scenario is beyond comprehension:
- UK Met Office: Catastrophic climate change, 13-18°F over most of U.S. and 27°F in the Arctic, could happen in 50 years, but “we do have time to stop it if we cut greenhouse gas emissions soon.”
Drought and deluge “” Hell and High Water “” we ain’t seen nothing yet!
UPDATE: Climate Central has a nice piece, “Ocean Temperatures Show Possible Climate Change Connection to Australian Flooding.”
- The year of living dangerously. Masters: “The stunning extremes we witnessed gives me concern that our climate is showing the early signs of instability”; Munich Re: “The only plausible explanation for the rise in weather-related catastrophes is climate change”
- In other UK news: “Rain like this happens once every 1,000 years”
- Australian Scientists: Contrary to media reports, “our paper does not discount climate change as playing a role in this most recent drought, the ‘Big Dry’. In fact, there are indications that climate change has worsened this recent drought.”
- President Obama explains the science behind climate change and extreme weather
- Northeast hit by record global-warming-type deluge
- Coastal North Carolina’s suffered its second 500-year rainfall in 11 years
- Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.”