Scientists say 2024 it is on track to become the hottest year on record.

In its latest State of the Climate report, released on the first day of the COP29 climate summit in Baku, Azerbaijan, the World Meteorological Organization paints a sobering picture. 

The report shows 2015-2024 to be the warmest decade since records began. For 16 consecutive months (June 2023 to September 2024), "the global mean temperature likely exceeded anything recorded before, and often by a wide margin," the study found.

In addition, between January and September 2024, the average global air temperature was 1.54 degrees Celsius (2.77 degrees Fahrenheit) above the pre-industrial average.

This rise means the past months have seen the world temporarily surpass a critical threshold laid out in the Paris Agreement.

What does surpassing 1.5 degrees Celsius mean?

The goal of the Paris Agreement, as agreed by almost every country in the world at the COP21 climate summit in 2015, is to limit global warming to well below 2 degrees Celsius and to strive for 1.5. 

Scientists have long warned that crossing that lower threshold is a physical limit beyond which Earth enters a danger zone where climate tipping points can create further warming.

A separate report published this month by the EU's Copernicus Climate Change Service also concluded that the annual temperature for this year would likely be more than 1.5 degrees.

"It's this relentless nature of the warming that I think is worrying," said Copernicus Director Carlo Buontempo.

The WMO report said that for now, the passing of the 1.5 threshold is temporary and does not mean a failure to meet the Paris Agreement goal. The long-term global temperature increase is estimated at around 1.3 degrees Celsius.

"Recorded global temperature anomalies at daily, monthly and annual timescales are prone to large variations, partly because of natural phenomenon such as El Nino and La Nina," said WMO Secretary-General Celeste Saulo. "They should not be equated to the long-term temperature goal set in the Paris Agreement."

The WMO report underscores the urgency of addressing climate change before crossing the 1.5 mark for good and warns that every fraction of a degree of warming matters. Even seemingly minimal temperature rise can exacerbate climate extremes, heightening the potential for heatwaves, floods, droughts and wildfires, which are already causing catastrophic losses around the world.    

Record-breaking greenhouse gas emissions, ocean heat and glacier loss

2023 already showed the highest observed levels of greenhouse gas emissions on record and real time data indicates they continued to rise in 2024. The volume of heat-trapping carbon dioxide increased by 51% between 1750 and 2023, according to the WMO report, pushing up temperatures. 

This is clearly visible in the world’s oceans, which absorb about 90% of the excess heat from global warming. They reached record heat in 2023 already, and preliminary data for 2024 shows a continuation of that trend. 

This oceanic heat content is irreversible. It will persist over the course of centuries or even millennia and its long-term effects will be felt for generations to come, the report says.

Simultaneously, glaciers around the world are losing ice at an accelerating rate.

In 2023 alone, glaciers receded more quickly that at any other point since records began 70 years ago — losing the equivalent of five times the volume of water held in the Dead Sea. The loss is attributed to extreme melting in North America and Europe. 

Rapid glacial melt contributes to rising sea levels, which are now increasing at more than double the rate observed between 1993 and 2002.  

 

Economic and human toll

As the Earth heats up, the consequences are being felt across the globe. In 2024, extreme weather events have caused devastating human and economic losses. From deadly heatwaves to torrential flooding, tropical cyclones, wildfires and severe drought, communities are struggling to cope with a new reality of more frequent and intense climate-related disasters.

The WMO report highlights how these events have had severe impacts on food security, water availability and human health and how they have exacerbated existing inequalities and displaced millions of people worldwide. 

"Climate catastrophe is hammering health, widening inequalities, harming sustainable development and rocking the foundations of peace. The vulnerable are hardest hit," said UN Secretary-General António Guterres.

Strengthening climate action and preparedness

In response to this growing crisis, the WMO has emphasized the need for urgent action on both reducing greenhouse gas emissions and enhancing climate adaptation strategies. 

On the latter, the report highlights progress made in climate services and early warning systems. Through initiatives like Early Warnings for All (EW4All), the global community is working to ensure that vulnerable populations are better prepared for increasingly extreme weather events.

More than 100 countries have multi-hazard early warning systems, helping to save lives and livelihoods when disasters strike.

Nevertheless, the WMO makes clear the need for stronger, more coordinated action.

"Every additional increment of global warming increases climate extremes, impacts, and risks," Saulo said, adding that immediate steps to cut emissions and invest in climate resilience are essential to minimize future losses.

Edited by: Tamsin Walker