People walk past a billboard in Miami Beach discussing sea level rise: dozens of trucks have started dumping hundreds of thousands of tons of sand on Miami Beach as part of US government measures to protect Florida's tourist destinations against the effects of climate change.

UN Secretary General Antonio Guterres warned Tuesday that while the global outbreak of coronavirus may have caused a temporary drop in emissions that cause global warming, it would not end the problem and might even divert attention from the fight.

"We should not overestimate the fact that emissions have been reduced for some months. We will not fight with the virus," he said.

"It is important that all the attention that needs to be given to fight this disease does not distract us from the need to defeat climate change," he said.

Guterres was speaking after the publication of a UN report on planetary warming last year, and said the situation demanded .

"Global heating is accelerating," he said as the World Meteorological Organization (WMO), a UN institution, presented its update.

The WMO report confirmed findings in December that 2019 was the second hottest year on record, "with the past decade the hottest in human history," Guterres said.

"We have no time to lose if we are to avert climate catastrophe," Guterres emphasized. "Let us have no illusions. Climate change is already causing calamity, and more is to come."

The WMO report looked at different aspects of climate change, from the accelerating sea level rise due to melting ice to changes in land and .

The planet will continue to warm up if greenhouse gases continue to increase, said WMO Secretary General Petteri Taalas.

"We just had the warmest January on record. Winter was unseasonably mild in many parts of the northern hemisphere," Taalas said.

"Smoke and pollutants from damaging fires in Australia circumnavigated the globe, causing a spike in CO2 emissions," he said.

"This is exposing and islands to a greater risk of flooding and the submersion of low-lying areas."

Manuel Pulgar-Vidal with the World Wide Fund for Nature agreed with the urgent demand for action.

"We are in a critical year for action—the longer we wait, the harder the challenge of addressing the climate crisis is going to get," he said in a statement.

Guterres said that while both the coronavirus and climate change needed a concerted to counter, the two challenges were very different.

"One is a disease that we all expect to be temporary and its impact we also expect to be temporary," he said. "The other is change which has been there for many years and which will remain with us for decades and require constant action."