2°C not ‘safe’: World must ‘completely decarbonise’ in 30 years

The world must almost completely decarbonise in the next 30-35 years, and the vast majority of fossil fuels be left in the ground, if we are to have any hope of tackling climate change effectively, a new Climate Council report has warned.

The warning is based on one of the major findings of the report: that the scientific case behind 2°C as a “safe” level of global warming – a figure that has underpinned climate policies around the globe – is rapidly weakening.

The report – Growing Risks, Critical Choices, released on Tuesday – finds that, compared to four years ago when the Climate Council’s Critical Decade report was published, the risks of climate change now looks more serious at lower levels of warming.

“The scientific underpinning for the 2°C policy target being a ‘safe’ level of climate change is now weaker than it was a decade ago,” the report says.

“The scientific case for a 1.5°C limit is more consistent with our current level of understanding, bolstering the case for even more urgent action.”

It is a worrying revelation, particularly considering how many major countries’ official emissions targets are deemed to be “not consistent” with the goal of keeping global warming below 2°C – Australia being chief among them.

As we reported here earlier this month, the Abbott government – with its 2030 target of 26-28 per cent reductions on 2005 levels – is the worst performer on two key measures: per capita emissions and emissions intensity. It is also in the bottom three of aggregate targets from a range of different years, and on reductions per year.

Meanwhile, the impact of climate change on Australia is already being felt. The Climate Council report, which reaffirms that it is “beyond doubt” that global warming is being driven by human activities, says hot days have doubled in the last 50 years, while heatwaves have become hotter, last longer and occur more often.

Over the last 30 years, it notes, extreme fire weather has increased in the southeast region of Australia, including southern NSW, Victoria, Tasmania and parts of South Australia. Extreme sea-level events have tripled at Sydney and Fremantle since the middle of the 20th Century.

From 2020 onwards, the report says the predicted increase in drought frequency is estimated to cost Australia $7.3 billion annually, reducing GDP by 1 per cent per year.

If global temperatures happen to reach 3°C above pre-industrial levels, the report says this would put an estimated 8.5 per cent of the world’s species are at risk of extinction.

Under a “business as usual” scenario, leading to global warming of 4°C or more, a staggering one in six species could be lost, the report says.

“The more we learn about climate change, the riskier it looks,” the report says. “The climate change landscape today stands in stark contrast to where it stood four years ago.

“Halfway through the Critical Decade, many consequences of climate change are already evident, and the risks posed by further climate change are better understood.

“It is clear that global society must almost completely decarbonise in the next 30-35 years, or sooner if possible, to tackle the climate change challenge effectively. This means that the vast majority of fossil fuels must stay in the ground.”