When much of southeast Australia faced abnormally hot and dry weather last summer, forecasters put it down to a high-pressure system blocking clouds from forming. But rising greenhouse gases were also to blame, researchers have found.
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| Human-caused climate change is robbing crucial rain from southern parts of Australia by shifting Southern Ocean westerly winds towards Antarctica, according to a new study. Photo: supplied |
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| An ice core in a drill that researchers used to study the climate of Antarctica. Photo: supplied |
The ANU's lead researcher associate professor Nerilie Abram said the hijacking of rain combined with 2015 being Australia's fifth-warmest year on record and 2016 on track to be the hottest was an ominous mix.
"The findings confirm that climate change is already having an impact on parts of Australia."
When looking at rainfall in southeast Australia, particularly the ACT and NSW, Professor Abram said it was important to consider other weather events such as El Nino phenomenons, which cause hot and dry conditions.
"But certainly in terms of the very long heat wave we saw in February and March, that was associated with the very strong winds heading south towards Antarctica," she said.
Professor Abram said the study, published in Nature Climate Change, showed southwest Australia was hurting the most from the change, where it had lost one fifth of its rainfall since the 1970s.
Humans have caused climate change for 180 years.
But she said more research was needed to understand the long term impacts on that region and the rest of Australia.
"Antarctica and the Southern Ocean experience extreme fluctuations in climate year to year," she said.
"What this research shows shows us is that we need to keep putting money into research to find out how Antarctica's climate is being affected because it directly affects our lives in Australia."
A 2015 study between CSIRO and Bureau of Meteorology found climate change would hit Australia harder than other countries, predicting a rise in temperature of more than five degrees within 80 years.
They forecast reduced rain in southern Australia over the next few decades as well as harsher fire seasons for southern and eastern parts of the country.
This August, Germany-based researchers Climate Analytics found the difference between 1.5 and 2 degrees of warming – the two goals included in the Paris climate deal – would be much greater in terms of extreme events and disasters than previously believed.
It found that within just 10 - 20 years, southern Australia would face heatwaves on average 13 days longer at 1.5 degrees and 20 days longer at 2 degrees, while dry spells would be 3.5 days longer at 1.5 degrees and six days at 2 degrees.
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