terça-feira, 10 de fevereiro de 2015

More Research Links Australia’s Extreme Heat To Climate Change

During the historic heatwave of 2013, scorching wildfires blazed across Australia, their smoke and toxic fumes forcing families from their homes. In the small fishing village of Dunalley, Tasmania, the Holmes family took shelter in the only place that was safe — the ocean. As they clung to a wooden dock, the fire engulfed and destroyed their village.

The severity of that wildfire was partially due to a record-breaking heatwave in Australia, an event which later came to be called the “angry summer.” On Thursday, a report released by the independent Climate Council of Australia concluded that that heat wave would have been “virtually impossible” without human-caused climate change.

“The evidence on the link between climate change and extreme heat is stronger than ever, and in fact is overwhelming,” the report says. ” Whether one considers the fundamental physics, the observed long-term trends in extreme heat, or the new model- and observation-based analyses of record years or individual events, the answer is absolutely clear. Extreme heat is becoming more frequent and more severe, and climate change is the primary reason.”

The research represents the second time Australia’s 2013 heatwave, which set new national daily average maximum temperature records as high as 118°F, has been linked to climate change. Indeed, the Climate Council’s report is partially based on peer-reviewed research published this past September in the Bulletin of the American Meteorological Society, which found that human activity caused a “substantial increase in the likelihood and severity of the record 2013 temperatures in Australia.”

Building on that research, the Climate Council’s study — which is not published in a peer-reviewed journal — pulled together papers from the Australian government, the U.N. Intergovernmental Panel on Climate Change, and at least five other peer-reviewed journals to claim that climate change is “stacking the odds” toward record-breaking heat in the country. It noted that record hot days have doubled in Australia in the last 50 years, while record cold days have declined by a similar number. Citing data from the Australian government’s Bureau of Meteorology, the group said that the last two years in Australia have been the hottest ever recorded.

 The number of days each year where the Australian area-averaged daily mean temperature is above the 99th percentile for the period 1910-2013. The data are calculated from the number of days above the climatological 99th percentile for each month and then aggregated over the year.
The number of days each year where the Australian area-averaged daily mean temperature is above the 99th percentile for the period 1910-2013. The data are calculated from the number of days above the climatological 99th percentile for each month and then aggregated over the year.
CREDIT: ClimateCouncil.Org.Au/Australia Bureau of Meteorology

The study also pulled together data that showed how heatwaves have been affecting Australian cities differently from 1950 to 2013. In Melbourne, it said, the hottest heatwave day is now 2°C hotter than it was in 1950, and the average heatwave now starts about 17 days earlier. In Sydney — the country’s most populated city — heat waves now start 19 days earlier. The hottest heatwave day is 4.3°C hotter in the city of Adelaide, and the number of heatwave days has almost doubled. In Canberra, the number of heatwave days has more than doubled.

“All extreme weather events, including extreme heat events, are now occurring in an atmosphere that is significantly hotter than it was 50 years ago,” the report said. “The additional heat in the atmosphere and surface ocean from human emissions of greenhouse gases drives up the risk of more intense heat and more frequent extreme heat events.”

The Climate Council is a crowd-funded Australian agency that is headed by climate activist Tim Flannery. It used to be part of the Australian Government (Flannery also headed it at that time), but was eliminated after Prime Minister Tony Abbott took office. Abbott has been heavily criticized by environmentalists for dismantling what had at one point been an ambitious climate change framework in the country. Along with defunding the Climate Council, he has gutted his country’s cap-and-trade carbon pricing system, and abandoned the country’s emissions reductions target.

From a public health perspective, heat waves are problematic. Extreme heat increases the risk of heat stroke, and can exacerbate cardiovascular, respiratory, and cerebrovascular conditions. Wildfires mean smoke, which contains particulate matter, carbon monoxide, nitrogen oxides, and volatile organic compounds. With Australia’s instances of extreme heat projected to increase, the country’s own federal government predicts heat-related deaths could quadruple by 2050.

Because of that, the Council is calling on Abbott to take action on reducing carbon emissions through investing in clean energy technologies and engaging in the U.N. Climate Summit in Paris this December, which many consider the last chance for a global agreement that could feasibly keep the rise in global average temperatures under 2°C.

While this has normally been highly unlikely — many have speculated that Abbott wouldn’t even be invited to the Paris talks — the Guardian reported on Tuesday that Abbott might be warming up to the idea of reducing emissions. According to the paper, Abbott’s government is preparing to make “significant concessions” to member of the country’s Labor Party to set a new greenhouse emissions reduction target that would go into effect after 2020.

From: ThinkProgress

Nenhum comentário:

Postar um comentário