TheConversation

“When it rains, it pours” once was a metaphor for bad things happening in clusters. Now it’s becoming a statement of fact about rainfall in a changing climate. Across the continental U.S., intense single-day precipitation events are growing more frequent, fueled by warming air that can hold increasing levels of moisture. Most recently, areas north of Houston received 12 to 20 inches (30 to 50 centimeters) of rain in several days in early May 2024, leading to swamped roads and evacuations. Earlier in the year, San Diego received 2.72 inches (7 centimeters) of rain on Jan. 22 that damaged nearly 600 homes and displaced about 1,200 people. Two weeks later, an atmospheric river dumped 5 to 10 inches (12 to 25 centimeters) of rain on Los Angeles, causing widespread mudslides and leaving more than a million people without power. Events like these have sparked interest in so-called sponge cities – a comprehensive approach to urban flood mitigation that uses i...

In July 2024, all eyes will turn to Paris for the Summer Olympic Games. Spectators from around the globe will converge on the City of Light to watch athletes compete and to soak in the culture, romance and history of one of the world’s most recognizable cities. But an iconic Paris landmark, the Notre Dame cathedral, will still be under renovation after a devastating fire that ignited in the cathedral and burned for 12 hours on April 14, 2019. When the last embers were extinguished, most of Notre Dame’s wood and metal roof was destroyed, and its majestic spire had vanished, consumed by flames. Notre Dame is nearly 1,000 years old and has been damaged and repaired many times. Its last major renovation was in the mid-1800s. The massive beams that framed the structure were fashioned from European oak trees harvested 300 to 400 years ago. Today, these trees are common throughout north-central Europe, but few are tall enough to replace Notre Dame’s roof lattice an...

Dozens of wildfires are burning across Canada in May 2024 and sending unhealthy smoke blowing into the northern U.S. again. At the same time, the southeastern U.S. is getting smoke from Mexico, where drought conditions have been fueling fires. Last year, Canada’s record 2023 wildfire season introduced millions of Americans across the Midwest and northeastern states to the health hazards of wildfire smoke, with air quality alerts that reached levels never seen there before. Professional baseball games were postponed and the skies in New York City turned orange with haze, at times exposing millions of people to the worst air quality in the world. In some regions, the smoke hung on for days. The pressing question on many people’s minds: “Is this the new normal?” From our perspective as air quality scientists, we think the answer is likely “yes.” Global warming means more fires Hotter, drier conditions, coupled with dry grasses and underbrush...

A deadly heat wave gripped Asia for weeks in spring 2024, sending temperatures in India’s capital region over 120 degrees Fahrenheit (49 Celsius) in May. Campaigning politicians, news announcers and Indian voters waiting in long lines passed out in the oppressive heat. In June, hundreds of people on the Hajj, a Muslim pilgrimage to Mecca, Saudi Arabia, died in searing heat that reached 120 F (49 C) with high humidity. Most of the planet has suffered the dire effects of extreme heat in recent years. Phoenix hit 110 F (43.3 C) or higher for 31 straight days in summer 2023, and Europe saw unprecedented heat that killed hundreds and contributed to devastating wildfires in Greece. Mexico and neighboring regions were sweltering through a dangerous and long-running heat wave in 2024. Regardless of where or when a heat wave strikes, one pattern has been a constant: Older adults are the most likely to die from extreme heat, and the crisis is worsening....

The 2024 Atlantic hurricane season starts on June 1, and forecasters are predicting an exceptionally active season. If the National Hurricane Center’s early forecast, released May 23, is right, the North Atlantic could see 17 to 25 named storms, eight to 13 hurricanes, and four to seven major hurricanes by the end of November. That’s the highest number of named storms in any NOAA preseason forecast. Other forecasts for the season have been just as intense. Colorado State University’s early outlook, released in April, predicted an average of 23 named storms, 11 hurricanes and five major hurricanes. The European Centre for Medium-Range Weather Forecasts anticipates 21 named storms. Colorado State also forecasts a whopping 210 accumulated cyclone energy units for 2024, and NOAA forecasts the second-highest ACE on record. Accumulated cyclone energy is a score for how active a given season is by combining intensity and duration of all storms occurring within a gi...