Last month was the second warmest September on record globally in a year that is “almost certain” to be the warmest on record, Copernicus, the European Union’s Earth observation programme, said today.

September recorded extreme rainfall and destructive storms around the world, weather events occurring with greater severity and frequency as temperatures rise due to climate change.

The average global temperature last month was the second warmest since September 2023, according to the Copernicus service, which uses billions of measurements from satellites, ships, aircraft and weather stations for its calculations.

Last year was the hottest on record, but 2024 looks set to repeat that record.

How floods were caused around the planet

Global warming does not only mean an increase in temperature, but also the phenomenon of excess heat being trapped in the atmosphere and oceans.

Warmer air can hold more water vapor and warmer oceans bring more water evaporation, which affects rainfall and causes it to be heavier and more marked storms.

During September some parts of the world experienced “rainfall in a few days that would normally occur in a month”, explains Samantha Burgess, the deputy director of the Copernicus Climate Change Service.

“Extreme rainfall events this month, which we are seeing more and more often, have been exacerbated by the warmer atmosphere. The risk of extreme rainfall will continue to increase as temperatures rise,” added Burgess.

In a month of extreme weather, Hurricane Elin hammered the southeastern US, Hurricane Krathon hit Taiwan, while Storm Boris caused flooding and damage in central Europe.

Typhoons Yagi and Bebinka left behind massive devastation in Asia, while deadly floods hit Nepal, Japan, west and central Africa.

According to Copernicus, wetter-than-average conditions were observed in parts of Africa, Russia, China and Australia, while Pakistan was hit hard by the monsoons.

New high records

Copernicus announced that the period from January to September 2024 has already set record highs “making it almost certain that 2024 will be the warmest year on record”.

Fourteen of the past 15 months have recorded temperatures at least 1.5 degrees Celsius above the average relative to the pre-industrial era, i.e. the period 1850-1900.

This does not constitute a violation of the Paris climate agreement, which aims to limit the greenhouse effect well below 2 degrees Celsius and preferably 1.5 because this limit is measured over decades and not individual years.

But scientists warn that the 1.5 degree target looks unattainable.

As things stand today, international efforts to reduce global warming from emissions of greenhouse gases such as carbon dioxide will result in global temperatures rising by as much as 2.9 degrees Celsius by 2100, according to the United Nations Environment Program (UNEP).

Greenhouse gas emissions, mainly from burning fossil fuels, have risen in recent years even as scientists warn they must be halved this decade.