Following 2023 as the hottest year, January 2024 has been confirmed as the warmest on record globally – 0.12°C above the temperature of the previous warmest January in 2020.

January was the 8th month in a series of global temperature record-breakers, reported by the Copernicus Climate Change Service. June 2023 through to January 2024 were warmer than the corresponding months in any previous year, in records going back to 1850. 

We asked climate scientists at the National Centre for Atmospheric Science to explain the global climate conditions, why they are happening, and what they think about it.

“Another month, another unprecedented record. The consequences are all too clear: floods, heatwaves and storms, all made worse by climate change and our reliance on burning fossil fuels,” said Professor Ed Hawkins, a climate scientist at the National Centre for Atmospheric Science based at the University of Reading.

The temperature records set in 2023 and January 2024 are mainly driven by human emissions of greenhouse gases into the atmosphere, primarily due to ongoing fossil fuel burning that began in the 1800s during the Industrial Revolution.

Scientists are also investigating the role of regional climate and weather, ocean circulation, and El Niño.

Dr Kieran Hunt, a climate scientist at the National Centre for Atmospheric Science and University of Reading, explains what El Niño is:

“El Niño is a climate pattern that is defined as anomalous warming of surface and sub-surface waters in the eastern and central tropical Pacific Ocean. More specifically, El Niño is the name given to the warm phase of a larger phenomenon called El Niño-Southern Oscillation also known as ENSO.”

El Niño occurs every 2-7 years, and can warm the planet significantly (up to about 0.2°C averaged over a given year). 

Climate change causes the background temperature of the planet to be warmer, meaning periods of hot weather are likely to be more frequent and more intense. Alongside a strong El Niño, climate change is leading to unparalleled temperatures being recorded.

It is anticipated that 2024 will see more global temperature records broken, especially as El Niño is expected to continue through the first few months of the year.  

“Given that global warming has resulted in the ten hottest years on record all occurring since 2010, I think 2024 would have been likely to break the record even with a moderate El Niño. In reality, we actually had quite a strong one,” explains Dr Kieran Hunt.

The World Meteorological Organization advises that the ongoing El Niño could influence weather patterns, contribute to a further spike in temperatures both on land and in the ocean, and exacerbate extreme weather events like heatwaves, floods, and droughts. 

The Copernicus Climate Change Service has also stated that the 12-month period ending in January 2024 has exceeded 1.5°C above the pre-industrial level.

The Paris Agreement has set a goal of holding the increase in global average temperature to well below 2°C above pre-industrial levels – and to aim for 1.5°C. 

Breaking the 1.5°C – 2°C global warming threshold refers to long-term annual average global surface temperatures, not individual months or years. And so, the global temperature extremes in 2023 and January 2024 should not be misinterpreted to mean the Paris Agreement has been breached. 

Assuming that no drastic greenhouse gas emission reductions are implemented in the coming years, the planet is expected to overshoot 1.5°C global warming by the mid-2030s – in around 12 years from now. 

There is no sudden threshold where impacts of climate change get worse – the impacts increase as global temperatures increase. Breaching the 1.5°C threshold will bring severe climate and weather extremes, and large-scale damaging impacts.

Rising temperatures are causing serious changes to our climate, with consequences for food security, water resources, health and biodiversity. Extreme weather is also becoming more frequent and is a major threat to lives, livelihoods and infrastructure. 

Floods, droughts, and forest fires have become more common over the last few decades. 2023 saw wildfires across Europe, Canada and Hawaii, typhoons and floods in East Asia, and droughts in Spain.