Heat is likely to rise to record levels in the next 5 years, new analysis says
The news
Global temperatures are likely to reach record highs over the next five years, driven by human-induced warming and a climate pattern known as El Niño, World Meteorological Organization forecasters say. said Wednesday.
The previous record for hottest year on Earth was in 2016. There’s a 98 percent chance that at least one of the next five years will exceed that, the forecasters said, while the average from 2023 to ’27 is almost certainly the warmest year will be. five-year period ever recorded.
“This will have far-reaching consequences for health, food security, water management and the environment,” said Petteri Taalas, the secretary general of the meteorological organization. “We must be prepared.”
Why it matters: Every fraction of a degree brings new risks.
Even a small increase in warming could exacerbate the dangers of heat waves, wildfires, droughts and other calamities, scientists say. Elevated global temperatures in 2021 contributed to a heat wave in the Pacific Northwest that shattered local records and killed hundreds.
El Niño conditions may cause further unrest by shifting global precipitation patterns. The meteorological organization said it expected more summer rainfall over the next five years in places like northern Europe and the Sahel in sub-Saharan Africa and less rainfall in the Amazon and parts of Australia.
The organization reported that there is also a two-thirds chance that one of the next five years could be 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, hotter than the 19th-century average.
That does not mean that the world will have officially violated the ambitious target of the Paris climate agreement to limit global warming to 1.5 degrees Celsius. When scientists talk about that temperature target, they generally mean a longer-term average over, say, two decades to eradicate the influence of natural variability.
Many world leaders have pushed for the 1.5 degree limit to keep climate change risks to acceptable levels. But countries have waited so long to make the monumental changes needed to achieve this goal, such as drastically cutting fossil fuel emissions, that scientists now think the world is likely to reach that threshold by the early 2030s. will exceed.
Background: La Niña, a cooling influence, is on its way out.
The average global temperature has already increased by about 1.1 degrees Celsius since the 19th century, largely because humans continue to burn fossil fuels and pump heat-trapping gases such as carbon dioxide into the atmosphere.
But while that overall upward trend is evident, global temperatures can fluctuate a bit from year to year due to natural variability. For example, a cyclical phenomenon in the Pacific Ocean, the El Niño South Oscillation, causes year-to-year fluctuations by moving heat in and out of deeper ocean layers. Earth’s surface temperatures tend to be somewhat cooler during La Niña years and somewhat hotter during El Niño years.
The last record year, 2016, was an El Niño year. In contrast, the past three years have seen many La Niña conditions: While unusually warm, they were still slightly below 2016 levels. Now scientists expect El Niño conditions to return later this summer. Combined with steadily rising levels of greenhouse gases in the atmosphere, that will most likely cause temperatures to rise to new highs.