More dry days ahead, say scientists, reporting that southern Australia could experience five times as many droughts as we do now.
Credit: Veer Images
SYDNEY: Australia's climate could shift dramatically with five times as many droughts in southern Australia and no snow cover, according to a new report on the consequences of severe climate change.
The report, released by Australia's national science agency, the CSIRO and the University of Melbourne at the Four Degrees or More climate change conference in Melbourne reveals effect of global temperature increase of four degrees on the Australian climate and environment.
"It's important to note that although some climate change is inevitable, changes of the magnitude described here are still avoidable as long as we are able to significantly reduce global greenhouse emissions," said Penny Whetton, the senior principal research scientist leading the Better Scenarios project with the CSIRO Climate Adaptation Flagship in Clayton South, Victoria.
Discovering the changes
Researchers from the CSIRO and the University of Melbourne analysed the predictions of 23 currently available global climate models using data from the Coupled Model Intercomparison Project, a project that gathers data from around the world to make predictions on changes in world climate.
A statistical tool called a 'probability distribution model' was applied to the projected changes predicted by the models to find what changes would occur at certain levels.
These probability distribution functions were scaled to match scenarios of global warming for 2030 and 2070.
Climate predictions then and now
Previous projections by the CSIRO and the Bureau of Meteorology in 2007 predicted a temperature increase of at least 1 degree Celsius by 2030. “If emissions are low, we anticipate warming of between 1.5 degree and 2.5 degrees by 2070, with a best estimate of 1.8 degrees,” Whetton said in 2007. “Under a high emission scenario, the best estimate is 3.4 degrees Celsius with a range between 2.2 to 5.0.”
The 2007 report also predicted the effect of increasing levels of greenhouse gases on rainfall, showing decreases in overall and seasonal rainfall across Australia in the decades to come.
The new study gives a more solid prediction to the effects of a global climatic shift. If global temperatures increased by 4 degrees Celsius or more, it would result in temperature increases of between 3 degrees and 5 degrees for coastal areas and 4 degrees to 6 degrees for inland Australia, the report shows.
In addition, global climate shifts would affect precipitation patterns, with snow cover falling to zero in most regions across the Australian Alps. More notably, the annual rainfall over southern Australia, particularly in winter and spring, would decrease by up to 50%.
"Unlike anything experienced before"
The combined decrease in rainfall with rising evaporation levels of between 5% and 20%, would lead to droughts occurring up five times more often in the southern regions of Australia, the study said.
"Rapid global warming of 4 degrees Celsius would be unlike anything experienced before by modern human societies - presenting us with huge challenges in our ability to adapt," Whetton said.
Steven Sherwood, an atmospheric physicist and co-director of the Climate Change Research Centre at the University of New South Wales in Sydney, said that while the report, "follows a fairly standard methodology" in summarising the predictions of climate models, the estimates "must be taken with a grain of salt" because of the variability between the 23 models. "They don't all predict the same outcome, so a large range can sometimes appear - but this probably represents the best we can do at the moment," he said.
Sherwood continued, "Of course there is no guarantee that the actual outcome will even be within this range, all the models could be off. But if the models are wrong, it is just as likely to be in the direction of underestimating change rather than overestimating it. "Either way, it's better to be safe than sorry and we need to reduce greenhouse emissions now while we still can before it's too late."
been there, done that
This is like the predictions passed on by Prof' Tim Flannery. He said there would be no more rain for capital cities and no snow seen by children again. That was about 2006. Since then the opposite happened. The climate or weather variables have been very normal. To take 23 models as a basis of prediction beggars belief.
Boulderdash !!!
Boulderdash !!!
Boulderdash !!!
It's 'Balderdash'....
Unless you mean:
Boulderdash (noun): A highly-disputed account of damage caused by the severe impact of a large rock
climate change
People don't want to change their lifestyle. If you accept the climate is changing and don't do anything about it you feel guilty, but if you say no the climate is not changing or it's all part of a natural cycle, you win both ways. You don't have to alter your lifestyle and you don't feel guilty.
Fiddlesticks!
http://news.google.com/news/story?q=new+zealand+snow&hl=en&gl=us&bav=on.2,or.r_gc.r_pw.&biw=1262&bih=621&wrapid=tlif131318346412310&um=1&ie=UTF-8&ncl=dwdXbbRf5YwJuQMcwQPSFaeECk6-M&ei=JJdFTquWA82GsAKnpL2SCA&sa=X&oi=news_result&ct=more-results&resnum=4&ved=0CEQQqgIwAw
No snow eh?
Fail.
Climate change is not new
Climate change has been going on since the planet's birth, 454 Billion years ago. Some of the changes have been extreme, drops and increases of 10 degrees C. Yes, species have been wiped out, some areas have turned into deserts; for most of this planet's life it was not in an ice age as we are now. During the last galaciation, we came really close to being wiped out before our species even started. Co2 in the atmosphere dipped below the level needed for plant growth and all plants above sea level died. Without plants, no more oxygen and therefore no humans and no animals.
If you believe that our present climate change is more extreme than what has happened before and if you believe that your use of fossil fuels is to blame for it, then please stop using them. This whole global warming, AGW, climate change thing is just to make you happy about paying more to your government or just a way they can take more of your money.
Go Away
Will you idiots never learn? Crying wolf for patronage has trashed the likes of the CSIRO and BoM. Taxpayers are absolutely fed up with your nonsense alarmist modelling. Epic fail. Sack the CSIRO. And the sooner the better.
Global warming ?
Unless I get credible answers to 2 simple questions I think they don't know what they are talking about.
1. Without greenhouse gases the Earth would be minus 18 C - N.A.S.A. - Ok why is the moon 123 C - from N.A.S.A. ? How does Death Valley get to 55+ C ?
2. Only greenhouse gases absorb infrared radiation and re-radiate infrared thus heating the atmosphere and earth - the majority of the atmosphere does not have this property - I.P.C.C. So 99% of the atmosphere is not heated at all ? 99% of the atmosphere doesn't emit infrared radiation like everything else in the Universe ? So the warmth I feel right now inside my home is from less than 1% of the atmosphere ?
If the whole of the atmosphere absorbs heat and radiates infrared the only mystery is how they actually detect the tiny amount of radiation from less than 0.04%.
Clearly we are not being told the truth here.
I'm Amazed
I'm amazed that Cosmos publishes rubbish articles such as this one. The CSIRO, Tim Flannery and scores of others have been making predictions like this for the past twenty years. I'm yet to come across one of these predictions actually happening. When the CSIRO and the 'Climate Scientists' stop trusting their computer models to get it right and actually compare the models predictions with real world outcomes is when I may begin to accept what they have to say. Until then articles such as this should be regarded as the modern version of examining chicken entrails or crystal ball gazing, rather than science based forecasts. When Tim (8 metres) Flannery sells his river front estuary house and land and moves to higher ground then I'll accept that he at least believes the nonsense he spouts.
But being safe will definitely make us sorry.
Steven Sherwood states "Either way, it's better to be safe than sorry and we need to reduce greenhouse emissions now while we still can before it's too late."
The problem with this statement is that climatology doesn't really know if reducing greenhouse emissions will have a beneficial impact on climate - which Steven Sherwood acknowledges.
Yet we know that reducing greenhouse emissions will definitely have a very damaging impact on the economy - making us very sorry indeed.
This means that, contrary to Steven Sherwood's statement, the safest approach is to not force a reduction of greenhouse emissions until we know that it will definitely have an impact.