2024 Officially Declared Hottest Year, Surpassing 1.5°C Limit

The year 2024 set a new global record as the warmest on record, marking the first calendar year where global temperatures exceeded 1.5°C above pre-industrial levels.

The announcement was made on Friday by the Copernicus Climate Change Service, the European Union’s Earth observation program. It coincided with devastating wildfires sweeping through Los Angeles, California, an event scientists link to the intensifying effects of climate change.

This unprecedented global heat is largely driven by greenhouse gas emissions from burning fossil fuels. Until humanity achieves net-zero emissions, the warming will persist.

The urgency to drastically reduce greenhouse gas emissions has never been greater.

Copernicus Confirms 2024 as the Hottest Year on Record

The Copernicus findings align with other major global temperature datasets, confirming that 2024 was the hottest year since record-keeping began in 1850.

In 2024, the global average temperature was approximately 1.6°C higher than the late 19th-century average, which serves as a benchmark for pre-industrial levels.

On July 22 of the previous year, the daily global average temperature hit 17.16°C, setting a new record high.

Copernicus also reported that every year in the past decade ranks among the ten warmest on record. Carlo Buontempo, director of Copernicus, stated:

“We are now dangerously close to surpassing the 1.5°C threshold outlined in the Paris Agreement, with the average temperature over the last two years already exceeding this level.”

These elevated global temperatures, combined with record-high atmospheric water vapor levels in 2024, triggered unprecedented heatwaves and heavy rainfall, impacting millions of people worldwide.

Estimating the global average surface temperature is a complex task, with methods differing between organizations. However, the conclusion remains consistent: 2024 was the hottest year on record.

Greenhouse Gas Emissions and El Niño: Key Drivers of Record Heat

This record-breaking global temperature was driven by greenhouse gas emissions from human activities. Additionally, the El Niño climate phenomenon contributed early in the year, warming the Earth’s surface—especially across much of the central and eastern Pacific—and raising the global average surface temperature by up to 0.2°C.

According to Copernicus, 2024 was the hottest year on record for every continental region except Antarctica and Australasia.

However, Australia is also experiencing the effects of a warming climate. The Bureau of Meteorology announced last week that 2024 was the country’s second-hottest year on record, surpassed only by 2019. That year, an extremely hot and dry spring triggered the devastating Black Summer bushfires. In contrast, 2024 was wetter than average for Australia.

Despite this, 2024 set new heat records in the southwest, as well as in parts of central and eastern Australia. With the exception of April, unusual warmth persisted throughout the year, with August standing out for record-breaking temperatures.

Why Global Temperature Records Surpass Regional Trends

Global temperature records tend to be broken more frequently than regional ones because weather patterns are more variable locally than they are globally. For example, a stretch of unusually cold weather in one region can lower the annual average temperature there, preventing new records from being set.

This explains why Australia has only reached record-high annual average temperatures three times since 2000—in 2005, 2013, and 2019—while the global average temperature broke six records during the same period.

The Paris Agreement aims to limit global warming to 1.5°C above pre-industrial levels. With 2024 reaching approximately 1.6°C above pre-industrial levels, it might seem that this target has been missed—but that’s not the case yet.

Long-Term Trends Over Single-Year Fluctuations in Climate Assessment

The agreement’s success is assessed over longer-term temperature trends rather than individual years. This method accounts for natural climate variability and phenomena like El Niño and La Niña, providing a clearer picture of underlying climate change.

Still, the 2024 data serves as a stark warning. It highlights the significant challenge humanity faces in keeping global warming well below 2°C, let alone achieving the 1.5°C target.

Understanding climate change hinges on one key fact: the amount of greenhouse gases humans emit over time is closely linked to the rise in global temperatures.

This near-linear relationship means that every tonne of greenhouse gas emissions contributes roughly the same amount to global warming. Therefore, the quicker we transition to a decarbonized global economy, the sooner we can halt warming and mitigate its impacts.

While 2025 is unlikely to be as hot as 2024, given the end of El Niño, Earth will still face record-breaking global temperatures for at least the next few decades.

This underscores the urgency of accelerating efforts to decarbonize society and the economy. It’s not too late to change the long-term trajectory of Earth’s climate.

Read the original article on: Science Alert

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