Climate change

Food’s role in climate change has emerged as one of the defining challenges of our time. The journey of a steak, fruit or salad from the vast expanses of agricultural lands to the plates on our tables leaves a significant footprint on the environment. As earth, climate and atmospheric scientists, we track global greenhouse gas emissions and just published the most comprehensive assessment yet of a powerful greenhouse gas from food production: nitrous oxide, or N₂O. After carbon dioxide and methane, N₂O is the most consequential greenhouse gas humans are releasing into the atmosphere. While there is less N₂O than carbon dioxide in the atmosphere, it is 300 times more powerful at warming the planet, and it remains in the atmosphere, holding in heat, for over a century. Today, atmospheric N₂O levels are about 25% higher than before the Industrial Revolution, and they’re still rising at an accelerating rate....

Ocean-related tourism and recreation supports more than 320,000 jobs and US$13.5 billion in goods and services in Florida. But a swim in the ocean became much less attractive in the summer of 2023, when the water temperatures off Miami reached as high as 101 degrees Fahrenheit (37.8 Celsius). The future of some jobs and businesses across the ocean economy have also become less secure as the ocean warms and damage from storms, sea-level rise and marine heat waves increases. Ocean temperatures have been heating up over the past century, and hitting record highs for much of the past year, driven primarily by the rise in greenhouse gas emissions from burning fossil fuels. Scientists estimate that more than 90% of the excess heat produced by human activities has been taken up by the ocean. That warming, hidden for years in data of interest only to oceanographers, is now having profound consequences for coastal economies around the world. Understanding the role of the ocean in th...

When summer starts with a stifling heat wave, as many places are seeing in 2024, it can pose risks for just about anyone who spends time outside, whether they’re runners, people who walk or cycle to work, outdoor workers or kids playing sports. Susan Yeargin, an expert on heat-related illnesses, explains what everyone should think about before spending time outside in a heat wave and how to keep yourself and vulnerable family members and friends safe. What risks do people facing running, walking or working outside when it’s hot out? The time of day matters if you’re going for a run, or if you’re walking or cycling to work during a heat wave. Early risers or evening runners face less of a risk – the Sun isn’t as hot and the air temperature is lower. But if your normal routine is to go for a run midmorning or over lunch, you probably want to rethink exercising in the heat. Pretty much everywhere in the U.S., the hottest part of the day is be...

You’ve probably heard people say, “It’s not the heat, it’s the humidity.” There’s a lot of truth to that phrase, and it’s important to understand it as summer temperatures rise. Humidity doesn’t just make you feel sticky and uncomfortable – it also creates extra dangerous conditions on hot days. Together, too much heat and humidity can make you sick. And in severe cases, it can cause your body to shut down. Meteorologists talk about the risk of heat and humidity using the heat index, but it can be confusing. I’m a risk communication researcher. Here’s what you need to know about the heat index and some better ways meteorologists can talk about the risks of extreme heat. Outdoor workers can be at high risk of heat illnesses. Robert Gauthier/Los Angeles Times via Getty Images What is the heat index, and how is it measured? Heat index...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. My parents said the planet is getting too hot for people to live here. They called it climate change. What does that mean? – Joseph, age 12, Boise, Idaho Many countries have seen extremely hot weather lately, but in most of the inhabited world, it’s never going to get “too hot for people to live here,” especially in relatively dry climates. When it’s hot outside in dry places, most of the time our bodies can cool off by evaporating water and heat from our skin as sweat. However, there are places where it occasionally gets dangerously hot and humid, especially where hot deserts are right next to the warm ocean. When the air is humid, sweat doesn’t evaporate as quickly, so sweating doesn’t cool...