Scientists still can't figure out the reasons behind the unexpected record-breaking heatwave that stretched from 2023 to this year, raising concerns that the climate crisis may be progressing faster than previously thought. is causing.
Is it a cloud? Or is it delivery? Or maybe a massive volcanic eruption?
A parade of climate researchers at the American Geophysical Union (AGU) announced potential reasons for the apparent spike in global warming meeting But no one claimed to fully understand what has been happening to the world's climate since early last year.
“We did not expect 2023 to be such an exceptional year,” admits Robert Rohde, a climate scientist at the University of California, Berkeley, and colleagues, adding that last year's temperatures exceeded the global annual record by 0.2 degrees Celsius. stated in the words. “Surprisingly Banana.”
Humans are causing global warming by burning fossil fuels, and last year we were also affected by the El Niño phenomenon. El Niño is a naturally occurring weather phenomenon that typically increases global temperatures. “But this was not normal,” Rohde said. “Global warming and El Niño are the biggest factors, but something else was going on.”
“Maybe it's the clouds,” Rohde said. New research discovered Last year had record low cloud cover, which reduced the amount of reflective surfaces that deflect the sun's energy out of the atmosphere. “There was extra warmth because the Earth was absorbing extra energy due to the lack of clouds,” he says. “But that just begs the question, 'Why weren't there so many clouds?'”
Another potential explanation could be found in the measures that came into effect in 2020 to reduce the amount of air pollution emitted by ships. The rule significantly reduced this type of pollution, by up to 90%. According to another new paperThis reduces the amount of sulfate aerosols released into the atmosphere, which blocks incoming solar radiation and helps cool the Earth slightly.
A further contributing factor could be the 2022 eruption of the Hunga Tonga volcano, located in the South Pacific. Rohde said the eruption would spew 150 million tons of water vapor into the atmosphere, trapping more heat closer to the surface into 2023.
Among other factors considered, discussed in front of an audience of hundreds of other researchers, was a reduction in the amount of dust that normally flies up from the Sahara desert, which again acts as a shield from the sun. “It's also possible that there is some kind of climate change feedback that we don't understand,” Rohde said. “There is a possibility.”
High temperatures will continue through much of 2024, and scientists are still waiting to see if the unexpected warming will subside. This year is certain to be the hottest year on record, the first to be 1.5 degrees Celsius warmer than before the industrial revolution, and likely to frustrate long-term international efforts to keep temperature rise below this level. It suggests that there is.
This level of global warming is already causing dangerous heat waves, floods, and other disasters, and scientists need to understand whether the climate system is heating up at an eerie rate faster than previously expected. He says further research is needed.
“There's a lot of explaining to do, but there's more to do,” said NASA climate scientist Gavin Schmidt, who co-chaired the session.Raise your hand if you think thermal anomalies have been fully explained. participants were asked to do so. Only a few out of hundreds did.
