Earth experiences unprecedented 12-month heatwave

The planet has witnessed a year-long period of temperatures exceeding 1.5 degrees Celsius above the pre-industrial average for the first time in history, according to the latest data from the European Union’s Copernicus Climate Change Service (C3S). Scientists warn that this is a clear sign of the escalating climate crisis and its devastating impacts on people and nature.

A year of record-breaking heat

From February 2023 to January 2024, the global mean temperature was 1.52 degrees Celsius higher than the 1850-1900 reference period, which is widely used as a proxy for the pre-industrial era. This means that the Earth has experienced 12 consecutive months of temperatures above the 1.5 degrees Celsius limit that the Paris Agreement aims to keep global warming well below.

The C3S also confirmed that January 2024 was the warmest January on record, with temperatures 1.66 degrees Celsius above the pre-industrial average. This was the eighth month in a row that set a new monthly temperature record, surpassing the previous records by large margins.

The C3S, which is part of the European Centre for Medium-Range Weather Forecasts (ECMWF), produces monthly climate bulletins based on observations from satellites, ground stations, ships and aircraft. The bulletins provide a comprehensive picture of the state of the climate and its variability.

El Niño and human-induced warming

The exceptional warmth of the past year was partly driven by a strong El Niño event, a natural phenomenon that occurs every few years when the surface waters of the eastern Pacific Ocean become unusually warm. El Niño affects the global weather patterns and tends to raise the global temperature by about 0.2 degrees Celsius.

However, El Niño alone cannot explain the magnitude and duration of the recent heatwave. The main culprit is the human-induced greenhouse gas emissions, mainly from the burning of fossil fuels, that have been accumulating in the atmosphere for decades and trapping more heat. According to the Intergovernmental Panel on Climate Change (IPCC), the global temperature has already risen by about 1.1 degrees Celsius since the pre-industrial era, and is likely to reach 1.5 degrees Celsius by the early 2030s unless drastic actions are taken to reduce emissions.

“El Niño has given us a glimpse of what a 1.5 degrees Celsius world looks like, but it is not a permanent breach of the threshold. It is a warning to humanity that we are moving faster than expected towards the dangerous levels of warming that we agreed to avoid in the Paris Agreement,” said Samantha Burgess, C3S Deputy Director.

Extreme weather and climate impacts

The unprecedented heatwave has been accompanied by a series of extreme weather events and climate impacts around the world, highlighting the urgency and the cost of the climate crisis.

Some of the most notable examples include:

• A severe drought that has affected the Amazon basin, reducing the river flows and the rainfall, and increasing the risk of wildfires and deforestation.
• A record-breaking heatwave that hit parts of southern Europe in December and January, with temperatures reaching up to 30 degrees Celsius in some places, and causing wildfires, crop failures and health problems.
• A series of deadly wildfires that ravaged South America, especially Argentina, Chile and Bolivia, destroying millions of hectares of land, killing dozens of people and animals, and releasing huge amounts of carbon dioxide and smoke into the atmosphere.
• A massive rainfall event that brought floods and mudslides to California in January, after years of drought and wildfires, damaging thousands of homes and businesses, and displacing tens of thousands of people.
• A rapid melting of the Arctic sea ice, which reached its second-lowest extent on record in September 2023, and has been shrinking faster than expected, threatening the wildlife, the indigenous communities and the global climate system.

“These are not isolated incidents. They are part of a larger pattern of climate change that is affecting every region and every sector of the world. The impacts are becoming more frequent, more intense and more costly, and they are putting lives, livelihoods and ecosystems at risk,” said Joeri Rogelj, professor of climate science and policy at Imperial College London.

The need for urgent action

The C3S data adds to the growing evidence that the world is running out of time to avert the worst consequences of climate change. The IPCC has warned that limiting global warming to 1.5 degrees Celsius would require a rapid and deep reduction of greenhouse gas emissions, reaching net zero by 2050. This would entail a transformation of the energy, transport, industry, agriculture and land use sectors, as well as unprecedented levels of international cooperation and public participation.

However, the current pledges and actions by countries are far from sufficient to meet this goal. According to the UN Environment Programme (UNEP), the world is on track to warm by more than 3 degrees Celsius by the end of the century, unless there is a drastic increase in ambition and action. The UNEP has also estimated that the global emissions gap, the difference between the projected emissions and the level consistent with the 1.5 degrees Celsius target, is 29 gigatons of carbon dioxide equivalent per year by 2030, which is equivalent to the annual emissions of the six largest emitters combined.

The next opportunity for countries to raise their ambition and action is the 26th Conference of the Parties (COP26) to the UN Framework Convention on Climate Change (UNFCCC), which will take place in Glasgow, Scotland, in November 2024. The COP26 is expected to be a crucial moment for the implementation of the Paris Agreement, as countries are supposed to submit their updated nationally determined contributions (NDCs), which are their plans to reduce emissions and adapt to climate change.

“The C3S data shows that we are in a climate emergency and we need to act accordingly. We cannot afford to delay or to compromise on the 1.5 degrees Celsius limit. We need to see a radical shift in the political will and the public awareness to achieve a net-zero emissions world by 2050. The COP26 is a critical opportunity for the world to demonstrate its commitment and its capability to tackle the climate crisis,” said Johan Rockstrom, of the Potsdam Institute for Climate Impact Research.