The year 2017 may end up being the second hottest on record, the United Nations’ World Meteorological Organization said on Monday – the opening day of the Bonn Climate Change Conference in Germany.

The global mean temperature for January-September this year was 0.39 to 0.55 degrees Celsius above the average temperature during 1981-2010, and about 1.1 degrees above the pre-industrial era, a statement by the UN agency said.

The previous year, 2016, is set to remain the hottest year, because of the strong impact of the El Niño phenomenon. While 2015 and 2017 will have the next two places, the period 2013-’17 will be the warmest five-year period ever recorded, the organisation said.

The statement said that long-term indicators of climate change, such as increasing carbon dioxide levels, sea levels and ocean acidification “continue unabated”. “We have witnessed extraordinary weather,” Petteri Talaas, head of the WMO, said, giving examples of a spate of hurricanes in the Atlantic Ocean and Caribbean Sea, monsoon floods in Asia and drought in East Africa.

Around 200 countries have gathered in Bonn to step up efforts to make the 2015 Paris climate deal work. The discussions will go on till November 17.

“This is our moment of truth,” Fiji’s Prime Minister Frank Bainimarama, who is presiding over the talks, told delegates on Monday. Fiji is a Pacific island country, and is likely to be highly vulnerable to rises in the sea level as a result of climate change.

The Paris climate deal had suffered a setback after the United States withdrew from the pact soon after Donald Trump took over as the president.