The last five years are set to be the hottest on record, according to the World Meteorological Organisation (WMO).

In an official statement released on Monday at the opening of the United Nations COP23 climate change conference in Bonn, Germany, the WMO said 2013 to 2017 would break records, which is significant given 2017 did not experience the El Niño boost.

The average global temperature from January to September 2017 was approximately 1.1°C above the pre-industrial era, the WMO reported.

WMO Secretary-General Petteri Taalas said that although 2017 may not be the hottest on record, it still formed “part of a long-term warming trend”.

“The past three years have all been in the top three years in terms of temperature records,” Dr Taalas said.

“We have witnessed extraordinary weather, including temperatures topping 50°C in Asia, record-breaking hurricanes in rapid succession in the Caribbean and Atlantic reaching as far as Ireland, devastating monsoon flooding affecting many millions of people and a relentless drought in East Africa.

“Many of these events – and detailed scientific studies will determine exactly how many – bear the tell-tale sign of climate change caused by increased greenhouse gas concentrations from human activities.”

Dr Andrew King, a Climate Extremes Research Fellow at the ARC Centre of Excellence for Climate System Science at the University of Melbourne, said 2017 “provides a window to our warmer future”.

“This year fits into the long-term trend of global warming with more hot years set to come over the next decade or two,” Dr King said.

“We have now had a little over 1°C of global temperature rise due to human-caused climate change and even if we meet the Paris global warming targets we can expect to see more frequent and intense extreme weather events, especially heatwaves, in the future.”

Rising heat

It’s hot – and expected to get even hotter. Photo: Getty

According to the WMO report, long-term indicators of climate change, such as increasing carbon dioxide concentrations, ocean acidification, and the below average Arctic and Antarctic sea ice extent, show no signs of diminishing.

As a result, there is growing concern among experts about the impact of extreme weather events on global food security, which has a greater impact on developing and third-world countries, as well as on global health, specifically the increase in heat-related illness and death.

The global mean temperature for January to September this year was 0.39°C to 0.55°C warmer than the 1981 to 2010 average, which represents an approximately 1.1°C increase in temperature since the pre-industrial period.

Global sea surface temperatures for 2017 are also on track to be in the top three on record.

Dr Liz Hanna, an Honorary Senior Fellow at the Climate Change Institute at the Australian National University, said the WMO’s findings were “alarming, but not unexpected”.

“This escalation of warming should be sending alarm bells to all Australians, as Australia is over 10^oC hotter than the global average, and there is an upper limit to human tolerance to heat,” Dr Hanna said.

She criticised the government’s lack of action in combating Australia’s contribution to climate change.

“This surge in warming should prompt a surge in effort to ramp up Australia’s mitigation efforts, transitioning to renewables.”

More extreme extremes

The polar regions experienced a battering, with sea ice extent in both the Arctic and Antarctic well below average throughout 2017.

Arctic sea ice extent was at record-low levels in the first four months of the year; in the Antarctic, the annual minimum sea ice extent at a record-low in early March and the annual maximum extent near record-low levels in mid-October.

Global sea surface temperatures for the year are also on track to crack into the top three on record, with global ocean heat content at or near record high levels.