Scientists say human-induced climate change is exacerbating natural weather conditions and causing heatwaves to ravage Asia, Europe and North America, which could make 2023 the hottest year on record.

Here, experts explain why 2023 is so hot, and warn that these record temperatures will only get worse even as humanity drastically reduces emissions of planet-warming gases.

El Nino and others

After a record-breaking hot summer in 2022, the Pacific warming phenomenon known as El Niño is returning this year, warming the oceans.

“This may have provided a little more warmth to the North Atlantic, but since the El Niño event has just begun, this is probably only a small part of the effect,” Robert Rohde of the US temperature monitoring group Berkeley Earth said in an analysis. The group estimates that there is an 81 percent chance that 2023 will be the warmest year since the mid-19th century.

Dust and sulfur

Atlantic warming may also have been increased by the reduction of two substances that normally reflect sunlight from the ocean: dust from the Sahara Desert and sulfur aerosols from marine fuels. Temperature analysis in Rohde’s North Atlantic region noted “extremely low levels of dust from the Sahara in recent months”.

Carsten Haustein of Germany’s Federal Climate Service said this was due to unusually weak Atlantic trade winds. Meanwhile, new restrictions on shipping in 2020 have reduced emissions of toxic sulfur. “This doesn’t explain the entire current North Atlantic surge, but it may have increased its severity,” said Rhode.

“Still” anticyclones

Warming oceans affect the weather on land, causing heat waves and droughts in some places and storms in others. Richard Allan, professor of climatology at the University of Reading, said the warmer atmosphere absorbs moisture and expels it elsewhere.

Scientists have stressed the duration and intensity of long-duration anticyclone systems that bring heat waves.

“Where areas of stagnant high pressure over the continents persist, the air descends and warms, melting the clouds, forcing intense summer sunlight to dry the soils, warming the soil and the air above it,” and heat waves are “delayed” for weeks, Allan said.

“Hot air from Africa is now in place and high pressure conditions have begun in Europe, meaning that heat continues to rise in the warm sea, land and air,” added Hannah Cloke, a climate scientist at the University of Reading.

The role of climate change

Scientists from the Intergovernmental Panel on Climate Change (IPCC) said in their global summary report this year that climate change has caused deadly heatwaves to “become more frequent and intense in most land regions since the 1950s.”

Robert Vautard, director of France’s Pierre-Simon Laplace Climate Institute, said this month’s heatwaves were “not one phenomenon, but several at once.” “But it’s all made worse by one factor: climate change.”

Higher global temperatures are making heat waves longer and more intense. While climate change is the primary driver, it is one of the variables that humans can influence by reducing their fossil fuel emissions.

“We are moving from familiar and well-known natural climate fluctuations to uncharted and more extreme regions,” said Melissa Lazenby, senior lecturer on climate change at the University of Sussex.

“However, we have the opportunity to reduce our human impact on climate and weather and not create more extreme and prolonged heatwaves.”

heat forecast

Berkeley Earth has warned that the current El Niño could make the Earth even warmer in 2024. The IPCC said that although governments can limit climate change by reducing greenhouse gas emissions in countries, heatwaves could become more frequent and intense.

“This is just the beginning. Deep, rapid and sustained reductions in carbon emissions to zero may halt warming, but humanity will have to adapt to even more severe heatwaves in the future,” said Simon Lewis, head of global change science at University College London. Source