The European Union's Copernicus Climate Change Service (C3S) has confirmed in its latest Global Climate Highlights report that 2024 was the hottest on record.

The study reveals a rise of 1.6 degrees Celsius (2.9 Fahrenheit) above pre-industrial times — defined as the level between 1850 and 1900. Previously, 2023 was the warmest year.

At the international climate conference in Paris in 2015, 196 world leaders agreed to limit global warming to no more than 2 degrees Celsius and to pursue efforts to keep temperatures below 1.5 degrees (2.7 Fahrenheit).

Samantha Burgess, C3S's deputy director, told DW that the world is now "teetering on the edge of passing the 1.5-degree level."

She added that though the average of the last two years had already surpassed the threshold, it did not imply the Paris Agreement was broken, as the agreement is based on a mean calculated over decades and not individual years. But "it shows the trajectory we are on," she said, warning of the impacts.

"We know from our understanding of the climate system that the warmer the atmosphere is, the more likely we are to have these hazardous extreme weather events and that's what really impacts people and ecosystems," she said.

How have rising temperatures affected the weather?
So far, global average temperatures — as measured over decades — have reached 1.3 Celsius, an increase that has already seen devastating consequences.

In 2024, wildfires scorched parts of the Pantanal wetlands in Brazil and affected several countries in the region, while parts of Sudan, the United Arab Emirates and Spain were hit by heavy flooding. Heat waves struck in Europe and West Africa, and tropical storms swept across parts of the United States and Philippines.

Scientists working as part of World Weather Attribution, an organization that studies the links between extreme weather and climate change, found that 26 of the events they looked at last year were made worse or more likely to happen due to rising temperatures.

Human burning of fossil fuels for activities such as heating, industry and transportation is the main driver of global warming, but natural phenomena like El Nino have also played a part in pushing up temperatures over the past two years, said scientists at C3S.

Warming Oceans Raising Temperatures in 2025
Typically occurring every two to seven years, El Nino is associated with the warming of the central and eastern tropical Pacific Ocean, leading to overall average sea surface temperatures that are 0.51 degrees Celsius higher than the 1991–2020 average.

Sea surface temperatures are of particular concern to scientists because oceans store around 90% of the heat connected to global warming.

"It has acted as a buffer over the past half century, or 70 years, for us. We are exceeding that buffer capacity, and we are feeling that in terms of extreme events on land," said Brenda Ekwurzel, director of scientific excellence at the Union of Concerned Scientists nonprofit, who was not involved in collating the C3S data.

Although the El Nino phase ended in 2024, Burgess said the ocean is holding onto more heat than in previous cycles which could affect heat levels in the coming year.

"Until we see that effectively dissipate into the deep ocean, we're likely to continue to see very high temperatures, but maybe not record-breaking temperatures," she said.

Climate change a 'problem we need to talk about now'
Despite growing alarm over rising global temperatures, levels of greenhouse gas emissions in the atmosphere continue to grow. C3S reported that the rate of increase of carbon dioxide was higher than that observed in recent years. The gas, which remains in the atmosphere for 300 to 1,000 years, is most associated with rising temperatures.

John Noel, a senior climate campaigner at environmental NGO Greenpeace in the US, blamed the "grim milestone" of the hottest recorded year on "deliberate obstruction" by fossil fuel executives and political allies.

"We must dismantle the dangerous corporate delusion that fossil fuel expansion can continue without consequence. Instead, we must embrace the once-in-a-lifetime opportunity to build the zero-carbon infrastructure needed for a safe future that includes everyone," he said in a press statement.

Meanwhile, Burgess told DW that without immediate action it was unlikely long-term average temperatures could be kept under the 1.5-degree limit. But she added that the world should not abandon those targets, as every fraction of a degree matters.

"[Climate change] is not a future problem that we have to deal with or that future generations will have to deal with, it's a problem that we need to talk about now," she said.

"We need to make sure that whoever we vote for is taking action on issues that are important to us, to make sure we can mitigate future climate change and adapt to our existing climate," she added.