NEW YORK (BLOOMBERG) - There is about a 40 per cent chance that the global average temperature for at least one of the next five years will be 1.5 deg C higher than in pre-industrial times - and the odds are only going up.

That level of temperature increase would most likely be temporary, according to an annual climate update led by the British Meteorological Office and published by the World Meteorological Organisation (WMO).

But the figure is significant because most global leaders committed to taking actions that would limit global warming to 1.5 deg C and well below 2 deg C by the end of the century when they signed the Paris Agreement in 2015.

"We are getting measurably and inexorably closer to the lower target of the Paris Agreement on climate change," WMO secretary-general Petteri Taalas said in a statement. "It is yet another wake-up call that the world needs to fast-track commitments to slash greenhouse gas emissions and achieve carbon neutrality."

Last year tied with 2016 for the warmest on record, with temperatures 1.2 deg C above pre-industrial times.

The past seven years have been the warmest seven recorded, a sign that climate change is accelerating.

Man-made global warming is manifesting itself in phenomena such as rising sea levels, melting sea ice, and extreme weather events.

While a year with average temperatures 1.5 deg C warmer than pre-industrial times is likely to be a one-off phenomenon, that does not mean the next half-decade will come in below recent records either.

Average temperatures are likely to be at least 1 deg C warmer in each of the coming five years, with the WMO estimating they will be between 0.9 deg C and 1.8 deg C.

There is a 90 per cent likelihood that at least one year between 2021 and 2025 will become the warmest on record, dislodging 2016 from the top slot.

"These are more than just statistics," Mr Taalas said. Increasing temperatures mean "greater impacts on food security, health, the environment and sustainable development".

The next five years will likely bring more tropical cyclones in the Atlantic Ocean and more rain in high latitudes and the Sahel region of central Africa, compared with the average between 1981 and 2010.

This year, south-western North America will likely be drier than in the past, while the Sahel and Australia are likely to be wetter.

National commitments to cut greenhouse gas emissions currently fall far short of what is needed to fulfil the Paris Agreement, according to a United Nations analysis released earlier this year.

Global leaders are expected to present more ambitious climate goals ahead of the UN-sponsored COP26 climate talks, due to be held in Glasgow in November.

Pressure from the public, as well as international competition, has generated momentum on the policy front in recent months, although significant issues remain unresolved, including the creation of an international carbon market that would put a price on emissions.