Moody’s on Why 2023 Was So Warm and What Will Happen This Year

A Moody’s publication looks why it was so warm last year and the impacts the effects of global warming will have in 2024.

The publication “Warmest Year; Warmest Months: Climate Change and El Niño Edged the Global Closer to the Paris Accord Temperature Bound” notes that long-term warming trends associated with the increase in atmospheric greenhouse gases, which were then superimposed on the oscillations of the equatorial temperatures across the Pacific: The El Niño Southern Oscillation or ‘ENSO.’

The arrival of a moderate/strong El Niño was declared by the National Oceanic and Atmospheric Administration in June 2023. In an El Niño phase, hot water accumulated at the western edge of the equatorial Pacific spreads across the ocean, liberating vast amounts of heat, the publication notes.

The global average temperature for 2023 was 14.98 degrees Celsius, 0.17 degrees Celsius higher than the previous maximum in 2016. El Niño was also present between 2018 and 2019, but was relatively weak. Global temperature records were not exceeded, and then there was no El Niño until 2023.

The 2023 El Niño is now fading and is likely to pass into Neutral or La Niña conditions into the second half of 2024.

“However, as has already been seen, the influence of El Niño is still being felt in the record temperatures at the start of 2024,” the publication states. “The (Copernicus Climate Change Service) suggests that even though El Niño continued to weaken in the equatorial Pacific, marine air temperatures, in general, remained at an unusually high level.”

“Once the current El Niño has dissipated, we can then expect a few years that are not quite as warm as 2023 – until the next strong El Niño year breaks the 2023 record,” it continues. “The next El Niño could be in three years, or as many as seven years, as with the gap from 2016 to 2023.”

Heat Stress

Extreme levels of heat stress have more than doubled over the past 40 years, a trend that is expected to continue, according to a new brief from NASA.

The brief explains how climate change may make some places too hot to live, and how climate scientists are tracking a key measure of heat stress that can warn us of harmful conditions.

Heat stress is a leading cause of weather-related deaths in the U.S. each year, and heat waves are becoming more frequent and severe as Earth’s climate warms, according to the NASA brief.

While most people are familiar with a heat index, scientists conducting global climate studies are more frequently using a measure of heat stress called wet-bulb temperature. That’s the lowest temperature an object can cool down to when moisture evaporates from it. It measures how well bodies cool down by sweating when it’s hot and humid.

Like the heat index, wet-bulb temperatures are calculated using data on air temperature and humidity. According to the brief, the highest wet-bulb temperature humans can survive when exposed to the elements for at least six hours is roughly 95 degrees Fahrenheit.

Since 2005, wet-bulb temperature values above 95 degrees have been measured for short periods on nine occasions in subtropical locations including Pakistan and the Persian Gulf, and they appear to be becoming more frequent. Incidences of slightly lower wet-bulb temperature values in the 90 to 95-degree Fahrenheit range have more than tripled over the 40 years studied, according to the brief.

Greenwashing

An Amsterdam court ruled Dutch airline KLM misled customers through advertisements that suggested its flights are climate friendly with claims in advertisements “based on vague and general statements about environmental benefits, thereby misleading consumers.”

The carrier didn’t provide travelers with honest and concrete information, it said. Airlines depend on sustainable aviation fuels or buying carbon offsets to demonstrate how they are reducing emissions, but many of those steps are currently seen as inadequate, Bloomberg reported in an article this week on Insurance Journal.

Air France-KLM’s Dutch arm was one of the first major airlines to face a lawsuit over greenwashing when it was sued by environmental pressure groups in 2022 over allegations that the airline’s “Fly Responsibly” campaign created a false impression of its climate impact.

KLM paints an “overly rosy picture” of measures such as sustainable aviation fuels and reforestation which “only marginally reduce the negative environmental aspects and give the wrong impression that flying with KLM is sustainable,” the court said in its verdict. The airline has discontinued the ad campaign, Bloomberg reported.

More Heat Stress

Heat stress may reduce productivity, a potential worry for people who see it as an important part of economies.

A new study from the National University of Singapore called Project HeatSafe entails a large-scale study in Singapore and the region aimed at investigating the impact of rising heat levels on the health, productivity and well-being of occupational workers in tropical climates, as well as the impact of heat stress on a macroeconomic and national level.

The study also indicates heat stress causes lower fertility and reduced cognitive capacity.

The study examines wet-bulb globe temperature, a measure of heat stress in direct sunlight, which considers humidity, air temperature, wind speed and solar radiation, at 24 indoor and outdoor workplaces.

The study aimed to find out how workers and their employers perceived heat stress during the hottest months of the year (April to August), and the impact on productivity through surveys with 355 workers and 214 employers in Singapore.

It found the higher the physical and mental exertion in the job role, the higher the productivity and economic losses. Economic loss significantly increased along with workers exposed to adverse environmental conditions at the workplace, such as working under the sun or being exposed to additional sources of heat. For every hot day, it was estimated the reduced productivity during working hours translated into a median income loss of S$21 per worker, roughly 24% of the daily median salary of the surveyed workers, the study shows.

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