United Nations — The month of July this year "has re-written climate history books" with record heat waves "seen across the globe," the World Meteorological Organization said Thursday.

At the U.N., Secretary General Antonio Guterres sounded alarm bells on the global climate crisis, releasing new statistics from the Geneva-based global weather agency and the Copernicus Climate Change Program.

Guterres said, "We have always lived through hot summers. But this is not the summer of our youth. This is not your grandfather's summer."

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The month of July, the U.N. chief said, at least equaled if not surpassed the hottest month in recorded history. By next week, climate scientists will determine if the month surpassed all others, when the final days are included in the research.

"July 2019 will be around 1.2°C warmer than the pre-industrial era," the WMO estimated.

The previous hottest month of July, back in 2016, occurred during one of the strongest El Niño weather events ever, which contributed to global temperatures. This year, record temperatures were reached without the aid of an El Niño.

Europe experienced a life-threatening heat wave, with France, Germany, Belgium, the Netherlands and Britain all hitting record temperatures: 100 degrees Fahrenheit in London, 109 in Paris. The International Federation of Red Cross and Red Crescent Societies warned that the threat posed by extreme heat "will only become more serious and more widespread as the climate crisis continues."

At the U.N. Thursday, the Secretary General laid out what must be done: limit global temperature increases to 1.5 degrees C to avoid the worst impacts of climate change; cut greenhouse emissions by 45% by 2030; and achieve carbon neutrality by 2050.

"Arctic sea ice is now close to new record low levels," the new statistics, announced by the U.N. chief, said, adding that the heat which recently affected Europe is now beating down on the Arctic and Greenland.

According to the WMO, "more frequent, longer and more intense heatwaves are exactly what we expect as greenhouse gases continue to lead to a rise in global temperatures."

The organization also noted, "The last time the earth experienced a comparable concentration of CO2 [carbon dioxide in the atmosphere] was 3 to 5 million years ago when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now."

When world leaders come to U.N. headquarters in New York for the annual General Assembly two months from now, the focus will include a Youth Climate Summit on September 21 and a Climate Action Summit on September 23, a day before heads of state, including presumably President Trump, will speak.

The mandate, Guterres said, is: "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."

Asked if there is a message to the Trump administration, which withdrew from the international Paris climate accord, Guterres said that all nations have to do better.

"Preventing irreversible climate disruption is the race of our lives and for our lives," the U.N. chief said.