In 2023, El Niño is back, warming the oceans. (Representative)
Paris:
Scientists say man-made climate change is supercharging natural weather events, driving heatwaves across Asia, Europe and North America, making 2023 the hottest year since records.
Here experts explain why 2023 has been so hot, warning that these record temperatures will get worse even if humanity sharply cuts its planet-warming gas emissions.
El Nino and many more
After a record-warm summer in 2022, the Pacific warming phenomenon known as El Niño is back this year, causing oceans to warm.
“This may have provided some additional warming to the North Atlantic, although because the El Niño event has just begun, it is likely a small part of the effect,” wrote Robert Rohde of the US temperature monitoring group Berkeley Earth in an analysis.
The group calculated that there is an 81 percent chance that 2023 will become the warmest year since thermometer records began in the mid-19th century.
dust and sulfur
The warming of the Atlantic may also be accelerated by the reduction of two substances that normally reflect sunlight away from the ocean: blowing dust from the Sahara Desert and sulfur aerosols from shipping fuels.
In Rohde’s analysis of temperatures in the North Atlantic region, “dust levels from the Sahara have been exceptionally low in recent months.”
This was due to the unusually weak Atlantic trade winds, said Carsten Haustein of Germany’s Federal Climate Service Centre.
Meanwhile, new shipping restrictions in 2020 reduced toxic sulfur emissions. “This would not fully explain the current North Atlantic spike, but could increase its severity,” Rohde said.
‘stable’ anticyclone
Warming oceans affect land weather patterns, causing heat waves and droughts in some places and hurricanes in some places. Richard Allen, professor of climate science at the University of Reading, said the warmer atmosphere absorbs moisture and dumps it elsewhere.
Scientists shed light on the length and intensity of long-standing anticyclone systems that bring heatwaves.
Allen said, “Where stable high-pressure areas persist over continents, air sinks and heats, clouds melt, allowing intense summer sunlight to dry the soil, heat the ground and the air above.” does,” heatwaves “stay in place”, Allen said.
In Europe, “warm air coming in from Africa has now stabilised, with high pressure conditions meaning that heat continues to build up over warm sea, land and air,” said climate scientist Hannah Kloke from the University of Reading . ,
role of climate change
Climate change has made deadly heatwaves “more frequent and more intense” over most land areas since the 1950s, scientists from the Intergovernmental Panel on Climate Change (IPCC) said in their global summary report this year.
Robert Voutard, director of France’s Pierre-Simon Laplace climate institute, said this month’s heatwave was “not a single event but multiple impact events at the same time.” “But they are all strengthened by one factor: climate change.”
Higher global temperatures make heatwaves longer and more intense. Despite being the main driver, climate change is one change that humans can influence by reducing emissions from fossil fuels.
“We are moving from the normal and known natural fluctuations of climate into unknown and more extreme territory,” said Melissa Lazenby, senior lecturer in climate change at the University of Sussex.
“However, we have the potential to reduce our human impact on climate and weather and not cause more intense and longer-lasting heat waves.”
summer forecast
Berkeley Earth has warned that the current El Niño could make Earth even hotter in 2024.
The IPCC has said that heatwaves are at risk of becoming more frequent and intense, although governments can limit climate change by reducing countries’ greenhouse gas emissions.
“This is just the beginning,” said Simon Lewis, chair of global change science at University College London.
“Deep, rapid and sustained cuts in carbon emissions to net zero can stop the heat, but humanity will have to adapt to even more severe heat waves in the future.”
(Except for the headline, this story has not been edited by NDTV Staff and is published from a syndicated feed.)