World temperatures are likely to rise by more than 2 degrees Celsius this century, surpassing a “tipping point” that global climate deals aim to avert, scientists say.
A study published in the journal Nature Climate Change on Monday shows a 90 per cent chance that temperatures will increase this century by 2 to 4.9 degrees Celsius.
Researchers at the University of Washington found only a 5 per cent chance that warming could be at or below 2 degrees Celsius – one of the targets set by the 2015 Paris climate deal on limiting emissions of greenhouse gases that warm the planet.
Missing that target would have dramatic consequences on people’s livelihoods – such as prolonged periods of drought and rising sea levels – said Adrian Raftery, the lead author of the study and a professor at the University of Washington.
The study uses statistical projections based on total world population, GDP per capita and the amount of carbon emitted for each dollar of economic activity, known as carbon intensity.
“Our analysis shows that the goal of 2 degrees is very much a best-case scenario,” said Mr Raftery.
“It is achievable, but only with major, sustained effort on all fronts over the next 80 years.”
The research comes as the Bureau of Meteorology (BoM) reports that Australia has experienced its warmest July on record.
A BoM report to be released later today will show the country’s average July temperature was at its highest in more than 100 years, forecaster David Crock told the ABC.
“The warmest parts have been through Queensland, Northern Territory, northern Western Australia and New South Wales,” he said.
“The month has been dominated – at least in eastern Australia – by a ridge of high pressure which has seen very clear skies and a warm air mass sit over the country for days and weeks at a time.
“The inland areas have certainly been warmer away from the cooling influence of the ocean … but certainly some of the temperature anomalies extend right across northern Australia.
“Queensland had its warmest July on record for both maximum and minimum temperatures across the whole state – parts of Queensland have been very dry.”
According to the UN Environment Programme, world greenhouse gas emissions, mainly from burning fossil fuels, are now about 54 billion tonnes a year and should be cut to 42 billion by 2030 to get on track to stay below 2 degrees Celsius.