Addressing reporters at the UN headquarters on Thursday, the Secretary-General stressed the urgent need for the international community to work collectively on climate change ahead of the upcoming high-level Climate Action Summit, to be held on September 23.

The summit will be preceded by a Youth Climate Summit (Sept. 21).

"I have told leaders, from governments, businesses and civil society, that the ticket to entry is bold action and much greater ambition. I am telling leaders don't come to the Summit with beautiful speeches. Come with concrete plans - clear steps to enhance nationally determined contributions by 2020 and strategies for carbon neutrality by 2050," he underlined.

According to the latest data from the World Meteorological Organization, the month of July at least equaled if not surpassed the hottest month in recorded history, Guterres said.

He added that the heat wave is even more significant because the previous hottest month, July 2016, occurred during one of the strongest El Nino's ever and that was not the case this year.