This month is set to be the hottest on record, with UN chief Antonio Guterres warning the rise in temperatures meant the world was on the brink of an "era of global boiling".
Mr Guterres pleaded for immediate radical action on climate change, on Thursday, warning record-shattering July temperatures prove Earth has passed from a warming phase into an "era of global boiling".
Speaking in New York, the secretary-general said the intense heat across the Northern Hemisphere was "terrifying," adding that "the era of global warming has ended; the era of global boiling has arrived."
July 6 was the hottest day ever and the first three weeks of this month were the hottest such period since records began, analysis by an EU-funded organisation indicates.
Exceptionally high sea surface temperatures have contributed to the record-breaking figures, Copernicus Climate Change Service (C3S) has revealed.
Drastic increase in temperatures
Records were broken as extreme heatwaves have affected many parts of the world, including the US and Mexico, China and Southern Europe. Wildfires have raged amid the sharply rising temperatures.
“Record-breaking temperatures are part of the trend of drastic increases in global temperatures. Anthropogenic emissions are ultimately the main driver of these rising temperatures," Dr Carlo Buontempo, director of C3S, said in a statement.
This month’s temperatures, which averaged about 17 °C globally, according to a graph released by C3S, look set to break the record for the hottest month set in July 2019.
"It is extremely likely that July 2023 will be the hottest July and also the hottest month on record, following on from the hottest June on record," C3S said.
The stark findings were supported by a second report released on Thursday, led by Dr Karsten Haustein, a research scientist at Leipzig University.
The study revealed that this month is the hottest since records began and possibly the hottest for more than 100,000 years.
"It’s quite a lot above the old record," said Dr Haustein.
"We have all the data we need to know it’s the hottest month … We are at least 0.2 °C warmer than the old record, for 2019.
"Even if it turns out to be a bit cooler than my fairly sophisticated forecast, we’re still in record territory. This is the warmest July ever. It’s also the warmest month in absolute terms."
This month is thought likely to have been the warmest since the end, about 115,000 years ago, of an interglacial period called the Eemian interglacial period.
Dr Haustein based his conclusions on data from land and ocean weather stations, satellites and radiosondes, which are battery-powered devices carried up by balloon.
One factor causing temperatures to be particularly high at the moment is that the world is in an El Niño phase, which is associated with a warmer climate than the opposite La Niña system.
The La Niña system is associated with stronger east-to-west trade winds in the Pacific Ocean, which brings up colder water from the ocean depths and results in cooler temperatures.
On top of the effect of being in an El Niño phase are the effects of climate change, which have made the heatwaves of the kind experienced this month around the world, notably in the United States and Mexico, China and Southern Europe, much more likely.
"We have also seen extremely high rainfall in South Korea, in Brazil, in other parts of the world this July," said Dr Friederike Otto, a senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment, part of Imperial College London, who was also involved in the analysis.
"It’s not by chance this is happening while we’re having this hottest July ever. These heatwaves we’re having are not rare events at all in today’s climate.
"They will be expected every five years or 10 years; not a really extreme event. Without heat-induced climate change, this would’ve been so rare it would’ve been the statistical equivalent of impossible."
Droughts have also been made more likely and more intense and are leading to yet higher temperatures, Dr Otto said.
'Harsh reality' of climate change
Meanwhile, the July 6 record for the hottest day exceeds that of August 2016. C3S said July 5 and July 7 were almost as hot as July 6.
Dr Buontempo said July’s record was "unlikely to remain isolated this year", because forecasts by C3S suggested temperatures over land areas were set to remain "well above average".
During the first and third weeks of this month, global mean temperatures were more than 1.5 °C higher than the average temperature of pre-industrial times, before humans began releasing large quantities of greenhouse gases into the atmosphere.
The key aim of the Paris Agreement of 2015 was to limit average global temperature rises to 1.5 °C above pre-industrial levels.
While the 1.5 °C threshold has been breached this month, it has happened only temporarily and global average temperatures have yet to reach the limit set by the Paris Agreement.
However, given the cuts in global carbon emissions set out in the deal have not been brought in by nations, it is thought highly likely that the threshold will be breached irreversibly.
“The extreme weather which has affected many millions of people in July is unfortunately the harsh reality of climate change and a foretaste of the future,” said Prof Petteri Taalas, secretary general of the World Meteorological Organisation (WMO).
“The need to reduce greenhouse-gas emissions is more urgent than ever before. Climate action is not a luxury but a must.”
Global heatwave - in pictures
According to WMO predictions, there is a 98 per cent chance that one of the next five years will be the warmest on record.
Also, the WMO says there is roughly a two-thirds chance that one of the next five years will have an average temperature more than 1.5 °C above that of the pre-industrial benchmark period of 1850 to 1900.
Statistics from OurWorldinData indicate that six billion tonnes of carbon dioxide, the key greenhouse gas, were emitted globally by fossil-fuel burning and industry in 1990, a figure that had more than quadrupled, to above 25 billion tonnes, by 2000. Two decades later, in 2020, the figure had risen to more than 35 billion tonnes a year.
Global carbon emissions are continuing to increase, although growth has slowed, in part thanks to some governments investing heavily in renewable energy technology, such as solar and wind power.
Some analysis suggests that global carbon emissions could peak as soon as 2025, but to prevent the worst effects of climate change, scientists have said steep reductions must be introduced this decade.
C3S, which released the data about this month’s record-breaking temperatures, is part of the European Centre for Medium-Range Weather Forecasts, which works on behalf of the European Commission.