2023: The Hottest Year 
on Record Jan/Feb 2024

A major reason for this temperature increase was the development of a strong El Niño phase from the middle of 2023 in the Pacific ENSO (El Niño-Southern Oscillation), which can have a major, warming, and sometimes devastating impact on world weather. In late 2023 this combined with a strong positive Indian Ocean Dipole effect — a similar phenomenon on the other side of the world.

Berkeley Earth points out that the largest anomaly in the 19th century was from a “super” El Niño in 1877-78 combined with conditions in the Indian Ocean Dipole similar to those last year. This, it is said, led to widespread droughts in Asia, Brazil and Africa and an estimated 50 million human fatalities.

2023 also saw a significant rise in the sea temperatures in the North Atlantic and a weakening in the currents forming part of the Atlantic Meridional Overturning Circulation (AMOC). Seen as a once-in-100-years event, the researchers suggest this was as much to do with a lack of airborn dust from the Sahara last Summer and Autumn as the activity in the Pacific. But should this become a new norm, we are warned that the AMOC could fail, giving Europe a new Ice Age and sinking New York and Boston under rising sea-levels. We are encouraged not to panic.

Weather forecasters also observe that the current El Niño is peaking and could turn to the cooling El Niña phase of ENSO by mid-2024; but this cooling phase may not have a major impact on global temperatures until 2025. Berkeley Earth are predicting that temperatures in 2024 are likely to be hotter than in 2016 — the previous record high — and may even exceed those of 2023.

In addition, 2023 was notable for:

• New national record high annual averages for an estimated 77 countries, including Bangladesh, Brazil, China, Germany, Japan, and Mexico.
• Record annual average warmth in both the land-average and ocean-average.
• Record warmth in most ocean basins, including once-in-a-century levels of warmth in the North Atlantic.
• Record low Antarctic sea ice during the Antarctic winter.

IEA: Energy based emissions

Meanwhile, the IEA has recently published its annual CO₂ Emissions Report for 2023. It has a slightly different perspective.

Although total energy-related CO₂ emissions grew by 1.1% last year, this is considered to be a continuation of the recovery from the pandemic: the average rate of growth in the past decade has “only”been 0.5% a year — a rate of increase last seen in the 1930s during the Great Depression.

This provides a level of optimism that clean energy is starting to have a real effect. 2023 set a new record for the introduction of clean energy: some 540GW added from wind and solar photo-voltaic (PV) farms, 35% up on the previous year. “Between 2019 and 2023, total energy-related emissions increased around 900Mt. Without the growing deployment of five key clean energy technologies since 2019 — solar PV, wind power, nuclear power, heat pumps, and electric cars — the emissions growth would have been three times larger.”

Then the IEA points to the causes behind the increase last year (see graph). Two thirds of the increase can be directly related to two factors: weather (it was a hot year) and transport (private cars in China but more importantly — aviation).