Extreme weather

The U.S. power grid is the largest and most complex machine ever built. It’s also aging and under increasing stress from climate-driven disasters such as wildfires, hurricanes and heat waves. Over the past decade, power grids have played roles in wildfires in multiple states, including California, Hawaii, Oregon and Minnesota. When wind speeds are high and humidity is low, electrical infrastructure such as aboveground power lines can blow into vegetation or spark against other components, starting a fire that high winds then spread. Under extreme conditions, utilities may opt to shut off power to parts of the grid in their service areas to reduce wildfire risk. These outages, known as public safety power shutoffs, have occurred mainly in California, where wildfires have become larger and more destructive in recent decades. On April 5-6, 2024, Colorado utility Xcel Energy carried out that state’s first public safety power shutoff, cutting power to thousands of custo...

With the arrival of spring in North America, many people are gravitating to the gardening and landscaping section of home improvement stores, where displays are overstocked with eye-catching seed packs and benches are filled with potted annuals and perennials. But some plants that once thrived in your yard may not flourish there now. To understand why, look to the U.S. Department of Agriculture’s recent update of its plant hardiness zone map, which has long helped gardeners and growers figure out which plants are most likely to thrive in a given location. The 2023 USDA plant hardiness zone map shows the areas where plants can be expected to grow, based on extreme winter temperatures. Darker shades (purple to blue) denote colder zones, phasing southward into temperate (green) and warm zones (yellow and orange). USDA Comparing the 2023 map to the previous version from 2012 clearly shows that as...

Superstorms, abrupt climate shifts and New York City frozen in ice. That’s how the blockbuster Hollywood movie “The Day After Tomorrow” depicted an abrupt shutdown of the Atlantic Ocean’s circulation and the catastrophic consequences. While Hollywood’s vision was over the top, the 2004 movie raised a serious question: If global warming shuts down the Atlantic Meridional Overturning Circulation, which is crucial for carrying heat from the tropics to the northern latitudes, how abrupt and severe would the climate changes be? Twenty years after the movie’s release, we know a lot more about the Atlantic Ocean’s circulation. Instruments deployed in the ocean starting in 2004 show that the Atlantic Ocean circulation has observably slowed over the past two decades, possibly to its weakest state in almost a millennium. Studies also suggest that the circulation has reached a dangerous tipping point in the past that sent it into a precipitous, uns...

Wild weather has been roiling North America for the past few months, thanks in part to a strong El Niño that sent temperatures surging in 2023. The climate phenomenon fed atmospheric rivers drenching the West Coast and contributed to summer’s extreme heat in the South and Midwest and fall’s wet storms across the East. That strong El Niño is now starting to weaken and will likely be gone by late spring 2024. So, what does that mean for the months ahead – and for the 2024 hurricane season? What is El Niño? Let’s start with a quick look at what an El Niño is. El Niño and its opposite, La Niña, are climate patterns that influence weather around the world. El Niño tends to raise global temperatures, as we saw in 2023, while La Niña events tend to be slightly cooler. The two result in global temperatures fluctuating above and below the warming trend set by climate change. El Niño starts as warm water builds up a...

Electricity is essential to just about everyone – rich and poor, old and young. Yet, when severe storms strike, socioeconomically disadvantaged communities often wait longest to recover. That isn’t just a perception. We analyzed data from over 15 million consumers in 588 U.S. counties who lost power when hurricanes made landfall between January 2017 and October 2020. The results show that poorer communities did indeed wait longer for the lights to go back on. A 1-decile drop in socioeconomic status in the Centers for Disease Control and Prevention’s social vulnerability index was associated with a 6.1% longer outage on average. This corresponds to waiting an extra 170 minutes on average for power to be restored, and sometimes much longer. The top map shows the total duration of power outages over eight storms by county. The lower map is a comparison with socioeconomic status taken into account, showing that counties w...