As the planet experiences its hottest temperatures in more than 100,000 years, scientists at the United Nations meteorological agency have crunched the numbers and come to a grim conclusion: More record-breaking heatwaves are almost inevitable.
There is a nearly 90% chance that the planet will surpass the hottest year on record in 2023 over the next five years, the World Meteorological Organization (WMO) said in a report on Wednesday.
It's almost equally likely that at least one of the next five years will see global average temperatures rise to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above the dawn of the Industrial Revolution — the level of warming that countries sought to avoid in the 2015 Paris Agreement.
“The goal of limiting long-term global warming to 1.5 degrees is in jeopardy,” UN Secretary-General Antonio Guterres said in a speech Wednesday at the American Museum of Natural History in New York City. He called for urgent action on a number of fronts, including reducing carbon emissions, adopting renewable energy, helping poor countries finance their own climate change efforts and cracking down on the fossil fuel industry.
On the last issue, Guterres has repeatedly called for an end to taxpayer subsidies for oil and gas, but he also set his sights on a new goal: He called on governments to ban advertising for fossil fuel companies, likening oil and coal producers to the tobacco industry, which faces advertising restrictions around the world, and he called on media outlets and tech companies to stop running them.
“Fossil fuels are not only polluting our planet, they're also bad for brands,” Guterres said, referring to advertising and PR firms. “I call on these companies to stop contributing to the destruction of our planet.”
Some publications, including The Guardian, have stopped accepting fossil fuel ads. The New York Times accepts ads from oil and gas companies with some restrictions, such as banning them from sponsoring climate newsletters and climate events, a company spokesman said. The Times also doesn't allow fossil fuel companies to buy all of the ad inventory in every episode of its podcast, “The Daily.”
Earth's latest record-breaking warm streak began mid-last year and has not abated as a new summer approaches in the Northern Hemisphere.
Last month was the warmest May on record on Earth, the European Union's Copernicus Climate Change Service said on Wednesday, making it the 12th consecutive month that the global average temperature exceeded all previous records for this time of year. According to Copernicus, temperatures over those 12 months were 1.63 degrees Celsius warmer than the pre-industrial average.
The 1.5°C target is described in the Paris Agreement as a “long-term” goal — technically this means that the world would only fail to meet the agreement if temperatures exceeded the threshold for years or even decades, not just one year.
“A temporary violation does not mean that the 1.5 percent target will not be met forever,” Ko Barrett, deputy director-general of the World Meteorological Organization, said at a news conference. But what is now clear is that such violations will become more frequent in the future, she added.
The effects of the extreme heat are being felt around the world. In India and other parts of South Asia, temperatures have risen well above 110 degrees Fahrenheit in recent weeks, pushing many people to their breaking point. Millions of Americans in California, Nevada and Arizona have been hit by the season's first heatwaves this week.
Brazil's recent floods have caused widespread deaths and damage and could be the costliest disaster in the country's history. Scientists said this week that human activity has added extra heat energy to the atmosphere, making the heavy rains that caused the floods twice as likely to occur over several days.
Coral reefs around the world are experiencing the most widespread bleaching ever observed, driven primarily by rising ocean temperatures. The National Oceanic and Atmospheric Administration predicts this year's Atlantic hurricane season will be unusually rough, with 17 to 25 tropical storms. Record ocean temperatures are a major factor, providing thermodynamic fuel for the formation and intensification of storms.
As the planet continues to warm, “this sequence of the hottest months will be remembered as relatively cold months,” said Copernicus director Carlo Buontempo. If greenhouse gas emissions are cut quickly, he said, the planet could cool to its current temperature by the end of the century.
There's at least one reason to believe a temporary respite is on the way: El Niño, a natural climate phenomenon, is weakening. Periodic El Niño events redistribute vast amounts of heat in the Pacific Ocean, triggering shifts in global weather patterns that lead to warmer temperatures across the planet. This contributed, at least in part, to 2023's record-breaking temperature rise.
Other factors may linger longer. In a study published last week, a team of scientists led by geophysicist Tianle Yuan of the University of Maryland, Baltimore County, estimated that the planet may now be experiencing further warming for a counterintuitive reason: recent regulations that have drastically reduced air pollution from ships.
Burning fuel oil releases carbon dioxide, which contributes to global warming, but it also releases sulfur compounds that have a somewhat opposing effect: once in the atmosphere, these turn into particles that help cool the planet by reflecting sunlight back into space and promoting cloud formation.
These pollutants still harm human health and ecosystems, which is why the International Maritime Organization (IMO) has imposed new limits on sulphur emissions from ships from 2020. But in doing so, the organization may have unintentionally contributed to making the planet slightly warmer than it would have been, Dr Yuan and his colleagues estimate.
To scientists, the biggest cause of global warming remains clear: Atmospheric concentrations of the three most important man-made greenhouse gases—carbon dioxide, methane, and nitrous oxide—have been steadily increasing. Scientists estimate that at current rates of emissions, in the next five years or so, humans may have altered the atmosphere's chemistry so significantly that it will be extremely difficult to prevent temperatures from rising above 1.5 degrees.