environment

Look closely at a plant in your local park, your garden or even your kitchen, and you’re likely to see some damage. Whether a caterpillar has chewed away part of a leaf or a mealybug is sucking on sap, animals are constantly feeding on plants. Of course, herbivory, or plant predation, is not ideal for a plant’s survival. So plants have evolved many different defense mechanisms to inhibit this threat, including physical and chemical weapons. For example, cactuses arm their bodies with skin-piercing spines. Herbs such as mint, lavender and rosemary produce volatile scent compounds that can help deter herbivores. Other plants resort to bribing personal bodyguards by secreting thick, sweet nectar. Nectar is most commonly associated with flowers, where it is used to entice bees, birds or butterflies to move pollen from one flower to another. But other plants produce different types of nectar glands called extrafloral nectaries. Plants produce these glands to bribe ants...

Spring 2024 was unnerving for people across large parts of the U.S. as tornado warnings and sirens sent them scrambling for safety. More than 1,100 tornadoes were reported through May − a preliminary number but nearly twice the 30-year average at that point and behind only 2011, when deadly tornado outbreaks tore across the southeastern U.S. The U.S. experienced several multistate outbreaks in 2024. Tornadoes damaged homes from Texas to Minnesota and east to West Virginia and Georgia. They caused widespread destruction in several towns, including Greenfield, Iowa; Westmoreland, Kansas; and Bartlesville, Oklahoma. Barnsdall, Oklahoma, was hit twice in two months. In May, at least one tornado occurred somewhere in the country almost every day. Greenfield, Iowa, after a powerful EF4 tornado cut through the city on May 21, 2024, amid a deadly tornado outbreak. What causes some years to have so many tornadoes? I’m a meteorologist w...

The world’s coral reefs are like underwater cities, bustling with all kinds of fish and sea animals. Coral reefs cover less than 1% of the ocean, but they support an estimated 25% of all marine species, including many important fish species. The economic value of the services that these complex ecosystems provide is estimated at over US$3.4 billion yearly just in the U.S. Today, rising ocean temperatures threaten many reefs’ survival. When ocean waters become too warm for too long, corals expel the colorful symbiotic algae, called zooxanthellae, that live in their tissues – a process called coral bleaching. These algae provide the corals with food, so bleached corals are vulnerable to starvation and disease and may die if the water does not cool quickly enough. With global ocean heat at record levels, scientists have confirmed that a global coral bleaching event is underway. Since the beginning of 2023, corals have been dying in the Indian, Pacific and Atlantic...

Winters on the Great Lakes are harsh – so much so that the scientists who work there often focus on the summer months, when tiny microbes at the base of the food chain were thought to be most productive. However, emerging research is changing our understanding of these winter ecosystems and shining a light on a vibrant world of winter activity just below the ice. Scientists discovered in the early 2000s that communities of diatoms – tiny photosynthesizing algae – were thriving in the light under the wind-swept lake ice. But, it turns out, that was only part of the story. As the Great Lakes’ winter ice disappears – it hit record lows in the winter of 2023-24 – new analyses show that some diatoms appear to have a different way to create energy and survive in the dark, turbid ice-free water until summer. A thin slice of Lake Erie ice collected by a scientist has diatom algae growing on the bottom....

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...