"Science Shows How Climate Change is Baking Australia"

Science Shows How Climate Change is Baking Australia from Climate Central

As smoke billows from unnervingly early-season wildfires charring the Australian state of Tasmania, yet more dust is settling on the scientific discussion over how climate change contributed to last year’s deadly Australian heat.

Last year was Australia’s hottest on record. And each of a set of five research papers published Monday in a special edition of the Bulletin of the American Meteorological Society reached the same conclusion regarding the year of unprecedented heat. The research teams independently concluded — in two cases writing that they could do so with “essentially” 100 percent certainty — that climate-changing greenhouse gas pollution played a substantial role in fueling it.

Australia has left behind its climate of generations past and moved into an era where extreme heat waves and warm winter months, such as those of 2013, are more likely to occur, researchers concluded.

“They’ve left behind the climate that they used to have,” said NOAA research meteorologist Thomas Knutson.

Last year’s intense heat was perhaps most noticeable during summer, when temperatures of 120 degrees were recorded in some places. But the differences between recorded and average temperatures were greatest during the Austral winter and fall. Never in more than a century of record-keeping has the average Australian temperature reached last year’s level.

The high temperatures and frequent heat waves were the combined result of natural variation and human influence on the climate. Low rainfall that contributed to the hot conditions does not appear to have been caused by climate change, one of the research teams concluded. That natural phenomenon combined with unnatural climate change-juiced heat, however, leading to extraordinary temperatures. Heat waves killed hundreds of people, delayed play and injured players at Melbourne’s Australian Open, and caused 100,000 bats to spectacularly tumble from their perches, dead.

“We now have some very solid, quantitative work that says, ‘Hey, wait a minute, climate change is implicated in these things,’” said Australian National University professor Will Steffen, who was a climate commissioner until the new federal government terminated the nation’s climate advisory group. The former government agency has since reconstituted itself as an independent nonprofit....