Spike in global temperature fuels climate change fears

Each of the past 10 months has been a record for global surface temperatures, a US agency says. Photo: Planetary Visions Ltd
Each of the past 10 months has been a record for global surface temperatures, a US agency says. Photo: Planetary Visions Ltd
Carbon emissions from energy use have plateaued over the past two years, the IEA says. Photo: act\ian.warden

Carbon emissions from energy use have plateaued over the past two years, the IEA says. Photo: act\ian.warden

The world has lurched closer to the 2-degree global warming limit in recent months, prompting calls by scientists for clearer policies aimed at making Australia and other rich nations carbon-emissions neutral before 2050.

February's spike in global temperatures lifted temperatures to 1.21 degrees above the 20th century average, and were the biggest departure from the norm in 137 years of records. Temperatures over land were 2.3 degrees warmer than average, according to the US National Oceanic and Atmospheric Administration (NOAA).

The first half of March was also the hottest on record for Australia with the rest of the planet also on track for record heat, the Bureau of Meteorology said.

So far this year, 2016 is looking like no other in history, American meteorologist Eric Holthaus noted in an article for the FiveThirtyEight website this week:

Climatologists such as Stefan Rahmstorf​, from Germany's Potsdam Institute of Climate Impact Research, say the big El Nino event in the Pacific is topping up the background warming from climate change by about 0.2 degrees.

Complacency should be avoided, therefore, when the mercury's record run inevitably ends in coming months as the El Nino unwinds.

"It's important to take this hot spike as a reminder that this is a really urgent problem" said Professor Rahmstorf, who until last week was also a visiting professorial fellow at the University of NSW. "We are running out of time to avoid a 2-degree world."

The UK Met Office estimated last year we are roughly half way there, based on the estimated average of the 1850-1900 period.

Professor Rahmstorf said another half a degree of warming is already locked in - even without short-term fluctuations - taking us to the lower end of the 1.5-2-degree limit agreed on by almost 200 nations last December in Paris.

To keep under that mark, the world must reach carbon neutrality - storing as much as emitted - by the second half of the century with developed nations reaching that level by 2050 or sooner, experts say.

Pep Canadell​, executive director of CSIRO's global carbon project, said the latest data on atmospheric carbon dioxide (CO2) levels and emissions offer cause for both concern and optimism.

Last year, CO2 levels measured at NOAA's Mauna Loa site in Hawaii jumped 3.05 parts per million, the fastest increase in 56 years of observations.

Dr Canadell said the leap was made worse by the El Nino. The unusual heat and drought conditions led to vegetation taking up less CO2 than usual, while also creating conditions for the huge fires in Indonesia that blanketed much of south-east Asia for months and exceeded emissions from the whole of the US.

On the plus side, emissions from burning fossil fuels for energy have plateaued for the past two years, the International Energy Agency said earlier this month.

China's decreasing coal consumption - down 2.9 per cent in 2014 and 3.7 per cent last year - is a major reason for the stall in emissions growth.

China delivered as much as 90 per cent of the growth in CO2 since 1990 and "can make this go the other way", Dr Canadell said.

Another contributor has been the rise in renewable energy, with new wind, solar and hydro accounting for about 90 per cent of additional electricity generation in 2015, the IEA estimates.

"Renewables have turned out to be an unexpected success story," Professor Rahmstorf said.

However, cuts in emissions of greenhouse gases from other sectors of the economy - such as agriculture and industry - will be harder to achieve.

Stephen Sherwood, an atmospheric scientist at UNSW-based ARC Centre of Excellence for Climate System Science, said the recent surge in warming indicates the slowdown in surface temperature increases of the past 10-15 years is over.

"We knew that was never going to last," Professor Sherwood said, referring to what had been dubbed a "warming hiatus". "We're back on track to where the models were predicting."

Despite facing "an emergency in slow motion," political leaders have largely failed to take major steps to start cutting emissions, he said. "We're not even fighting the battle, so of course we're losing"

John Connor, chief executive of The Climate Institute, said putting a price on carbon was necessary to send "clear signals to the big emitters to take responsibility for their emissions".

"We don't have a clear policy of decarbonising our energy system,"he said.

While there's still time to avoid 2 degrees warming, Australia and other nations "have been given a massive hurry along by the huge extremes we're seeing now," he said.

"There are reasons to be optimistic," Mr Connor said. "But there also reasons to be terrified."

This story Spike in global temperature fuels climate change fears first appeared on The Sydney Morning Herald.