How global warming and La Niña fueled a summer of climate extremes

There’s an old joke about the fellow who has his left foot in a bucket of ice water and the right in a bucket of hot water, so that his overall temperature is average. That seems to apply to the climate during 2022’s northern summer of extremes: Overall, the planet was tied for only the fifth-warmest June-August, yet regional heat waves shattered records.

Global warming is undoubtedly a factor, but just how the increasing extremes that marked the summer of 2022—heat waves, droughts and floods, sometimes one on top of the other—are related can be bewildering to the public and policymakers.

As a climate scientist, I’ve been working on these issues for more than four decades, and my new book, “The Changing Flow of Energy Through the Climate System,” details the causes, feedbacks, and impacts. Let’s take a closer look at how climate change and natural weather patterns like La Niña influence what we’re seeing around the world today.

The Northern Hemisphere’s extreme summer

Summer 2022 has indeed seemed to feature one climate-related disaster after another.

Record-breaking heat waves baked India and Pakistan, then monsoon flooding left about a third of Pakistan under water, affecting an estimated 33 million people. Temperatures exceeded 104° Fahrenheit (40° Celsius) for prolonged periods in many places, and even broke 122° F (50° C) in Jacobabad, Pakistan, in May.

The Asian heat helped to melt some glaciers in the Himalayas, elevating rivers. At the same time, three times the normal annual rain fell in Pakistan during the weekslong monsoon. More than 1,500 people died in the flooding, an estimated 1.8 million homes were damaged or destroyed, and hundreds of thousands of livestock were lost. Food for the coming seasons will be in short supply.

Extreme heat in Europe led to wildfires, especially in Spain and Portugal. The drought in Spain dried up a reservoir, revealing the long-submerged “Spanish Stonehenge,” an ancient circle of megalithic stones believed to date back to around 5000 BC. Electricity generation in France plummeted, with low rivers reducing the ability to cool nuclear power towers, and German barges had difficulty finding enough water to navigate the Rhine River.