The past decade has been the hottest on record, the UN said on Wednesday, alerting that the increasing temperatures were expected to bring extreme weather events in 2020 and beyond.
The World Meteorological Organization said rising global temperatures had alarming consequences, pointing at "retreating ice, record sea levels, increasing ocean heat and acidification, and extreme weather."
"The year 2020 has started out where 2019 left off -- with high-impact weather and climate-related events," said WMO chief Petteri Taalas in a statement, pointing at the deadly bushfires raging in Australia.
The bushfires have claimed 28 lives and destroyed more than 2,000 homes and burnt 10 million hectares (100,000 square kilometres) of land.
They have become the starting point of disasters that scientists say the world will continue to face due to global warming and climate change.
"Unfortunately, we expect to see much extreme weather throughout 2020 and the coming decades, fuelled by record levels of heat-trapping greenhouse gases in the atmosphere," said Taalas.
The UN agency said that average global temperatures during both the past five-year (2015-2019) and 10-year (2010-2019) periods were the highest ever recorded.
"Since the 1980s each decade has been warmer than the previous one," the UN agency said in a statement, warning that "this trend is expected to continue."
Call For Immediate Action
"On the current path of carbon dioxide emissions, we are heading towards a temperature increase of three to five degree Celsius by the end of the century," Taalas warned on Wednesday.
WMO also highlighted a new study published in Advances in Atmospheric Sciences with data showing that ocean heat content was at a record high in 2019.
The past five years and the past decade also recorded the warmest on record in terms of ocean heat content, the study showed.
Since more than 90 per cent of excess heat is stored within the world's oceans, their heat content is a good way to quantify the rate of global warming, WMO said.
"It is no surprise that 2019 was the second hottest year on record -- nature has been persistently reminding us that we have to pick up the pace," said Manuel Pulgar-Vidal, leader of WWF's global climate and energy practice.