March 2, 2024

Is this ‘the new normal?’ There is no such thing, say some scientists



CNN

Summer in the Northern Hemisphere is playing out like an apocalypse movie: a story of heat, flood and fire. But scientists warn this could be just a preview of the unpredictable chaos to come if the world continues to pump planet-warming pollution.

Just over half way through July and some extreme weather records have already been broken.

A long, unrelenting heat wave has scorched large parts of the Southern and Southwestern United States. Temperatures in Phoenix, Arizona, have hit at least 110 degrees Fahrenheit (43.3C) for 19 consecutive days, and emergency departments are flooded with heat-related illnesses.

Southern Europe is experiencing one of the most extreme heat waves on record, with wildfires burning in Greece, Spain and Switzerland. And in Asia, temperatures have soared above 50 degrees Celsius (122 degrees Fahrenheit) in China, with deadly flooding in parts of South Korea, Japan and northern India.

I statement On Tuesday, Petteri Taalas, secretary general of the World Meteorological Organization, called this relentless cascade of extreme weather “the new normal.”

But some scientists now baulk at that framing.

“When I hear it, I get a little bit crazy because it’s not really new,” said Hannah Cloke, a climate scientist and professor at the University of Reading in the UK. “Until we stop pumping greenhouse gases into the atmosphere we have no idea what the future holds.”

She is one of many scientists who warn that while this summer has been very bad, it is only the beginning. As long as global temperatures continue to rise, they said, the world should watch for increasing impacts.

Michael E. Mann, a climate scientist and distinguished professor at the University of Pennsylvania, prefers to describe the weather we are seeing as “the new abnormal.”

The new normal “misconceives the idea that we’ve entered a new climate state and all we have to do is adapt to it,” he told CNN.

“But it’s much worse than that. The impacts get worse and worse as fossil fuel burning and warming continue. It’s a shifting baseline of increasingly destructive impacts as the Earth continues to warm.”

For scientists like Mann and Cloke, this year’s extreme weather is no surprise. The development of El Niño, a natural phenomenon that affects global warming, was expected to have a major impact on top of long-term human-caused global warming.

But regionally, there were “some significant anomalies,” said Mann, who cited record low levels of winter sea ice in Antarctica and “off the charts” warmth in the North Atlantic. “They are a reminder that if we continue to burn fossil fuels, we cannot expect to break records, but to be broken.”

A billboard shows Sunday's temperature in Phoenix.

As the climate crisis intensifies, the stage is set for more surprises.

“Weather extremes will continue to get more severe and our weather patterns could change in ways we cannot yet predict,” said Peter Stott, scientific fellow in climate attribution, at the UK Met Office.

In some cases, the heat, fire and floods are already greater than climate models predict, Mann said. In part, this is due to changes in the jet stream, he said.

The jet stream is driven by the temperature difference between the poles and the equator. As the Arctic warms, that temperature difference is reduced and the jet stream softens and weakens. This can mean that weather systems can be locked for long periods.

“The same region gets baked day after day, or it rains day after day – just the kind of behavior we’re seeing this summer,” Mann said.

It will be difficult for countries to adapt to these new extremes, said Vikki Thompson, a climate scientist at the Royal Netherlands Meteorological Institute. “We will see a combination of events that could lead to unexpected impacts. Heavy rains can affect society, agriculture and ecosystems in extraordinary ways quickly afterward,” she told CNN.

Countries usually prepare for the worst they have experienced, but with climate extremes breaking current records, “we have to prepare for situations that may be impossible right now,” he said. Thompson.

Although the world is already locked in some impacts of global warming, due to the global failure to reduce pollution warming planet, scientists are clear that there is still time to avoid the worst consequences.

The latest science shows that global warming would stop almost immediately after we stop burning fossil fuels, Mann said.

And there’s more evidence this summer that every fraction of what the world can do to limit global warming will count, Cloke told CNN. The planet is around 1.2 degrees Celsius warmer than it was before the industrial revolution – still short of the 1.5 degrees scientists are warning the planet should stay below. But even now, the consequences are fatal and far-reaching.

“It’s really scary,” she said. “But the more action we take, the sooner we take that action, the better our future will be.”

Read more:

Why the nighttime heat can be so dangerous – and why it’s getting worse

Summer is now a test of survival as the heat gets more extreme

2023 could be the hottest year on record

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