Climate change

When wildfire smoke is in the air, doctors urge people to stay indoors to avoid breathing in harmful particles and gases. But what happens to trees and other plants that can’t escape from the smoke? They respond a bit like us, it turns out: Some trees essentially shut their windows and doors and hold their breath. As atmospheric and chemical scientists, we study the air quality and ecological effects of wildfire smoke and other pollutants. In a study that started quite by accident when smoke overwhelmed our research site in Colorado, we were able to watch in real time how the leaves of living pine trees responded. How plants breathe Plants have pores on the surface of their leaves called stomata. These pores are much like our mouths, except that while we inhale oxygen and exhale carbon dioxide, plants inhale carbon dioxide and exhale oxygen. A highly magnified view of stomata in a maize leaf. Umberto Salvagnin/Fli...

A month into summer 2024, the vast majority of the U.S. population had already experienced at least one extreme heat wave, and millions of people were under heat alerts, with forecasts warning of more ahead. Death Valley hit 125 degrees Fahrenheit (51.7 Celsius) or higher for nine consecutive days in early July. Las Vegas broke its all-time heat record at 120 F (48.9 C). Days of 100-degree heat dried out the California landscapes, fueling wildfires there and in the Northwest. Oregon reported several suspected heat deaths. Globally, the planet had its hottest day in at least eight decades of recordkeeping on July 21 – and then broke the record again on July 22, according to the European Union’s Copernicus Climate Change Service. The extreme heat is part of a longer trend: Each of the past 13 months has been the hottest on record for that month globally, including the hottest June, the EU service reported in early July. It also found that the average temperature for t...

Strange as it may seem, early germ theorists could tell us a lot about today’s attitudes toward climate change. While researching for a new book about the history of emerging infections, I found many similarities between early debates over the existence of microbes and current debates over the existence of global warming. Both controversies reveal the struggles of perceiving an unseen threat. Both reveal the influence of economic interests that benefit from the status quo. But most importantly, both reveal how people with different beliefs and interests can still agree on key policies and practices for tackling a global problem. What you can’t see might hurt you Seeing is believing, and until the mid-19th century, it was very difficult to see the tiny organisms responsible for our so-called “fever” diseases. Although the indirect evidence was compelling, many people remained skeptical of “animalcules” – as microorganisms were once cal...

When wildfires rage, the immediate threat is obvious – but smoke from the fires actually kills far more people than the flames. As fires become more frequent, that smoke is leading to a public health crisis. In a new study published in the journal Science Advances, we found that wildfire smoke likely contributed to more than 52,000 premature deaths across California alone from 2008 to 2018, with an economic impact from the deaths of more than US$430 billion. Previous studies have examined the short-term health risks from wildfire smoke, but few have assessed how exposure to wildfire smoke over years adds up to shorten human lives. Smoke from far-off wildfires turns the skies orange over San Francisco in 2020. Running in wildfire smoke carries harmful particles deep into a person’s lungs. AP Photo/Tony Avelar Wildfire risk and severity have grown as the climate has changed and as more...

Hurricane Beryl was the latest Atlantic storm to rapidly intensify, growing quickly from a tropical storm into the strongest June hurricane on record in the Atlantic. It hit the Grenadine Islands with 150 mph winds and a destructive storm surge on July 1, 2024, then continued to intensify into the basin’s earliest Category 5 storm on record. Beryl was still a powerful Category 4 hurricane on July 3 when its eyewall brushed the coast of Jamaica and headed toward the Cayman Islands. A large part of Mexico’s Yucatan Peninsula was under a hurricane warning. The damage Beryl caused, particularly on Carriacou and Petite Martinique, was extensive, Grenada Prime Minister Dickon Mitchell told a news briefing. “In half an hour, Carriacou was flattened.” Beryl’s strength and rapid intensification were unusual for a storm so early in the season. This year, that is especially alarming as forecasters expect an exceptionally active Atlantic hurricane season....

Wherever people look, climate change is inflicting ever greater physical, economic, and mental costs on people and communities. From the impact of extreme weather events on food security to the growing spread of infectious diseases as weather patterns change, and with the rise of deadly heat waves, it is undeniable that what harms our planet also harms our health.  To meet the Paris Climate Agreement targets of limiting global temperature rise to under 1.5°C (2.7°F), every sector—including health care—must undergo decarbonization in adapting to this new reality. Health care is one of many sectors fueling the climate crisis, emitting more global carbon dioxide (CO2) emissions than the shipping industry.    In a new study, Unitaid sought to answer whether switching from one drug to another could provide lifesaving benefits while reducing carbon emissions. The findings reveal that this is not only possible, but also already...

The warming climate doesn’t only melt ice caps and bleach coral reefs but also puts your health at risk. Climate change is no longer a far-removed issue, able to be cast off as a problem “of tomorrow.” Climate change alters health both through long-term stressors, such as air pollution1 and vector-borne diseases2, and through acute events, such as heat waves3 and hurricanes.4 These long and short term elements collectively influence public health around the world.  Climate change has health consequences from the scale of entire populations all the way down to the level of your cells.5 Here are six things that are sometimes forgotten regarding climate and health:  Climate change is associated with infectious disease spread As temperatures rise, disease vectors like mosquitoes and ticks move northward into newly habitable terrain.2,6,7 This means that diseases that were previously only endemic to t...