TheConversation

You’ve just finished a cup of coffee at your favorite cafe. Now you’re facing a trash bin, a recycling bin and a compost bin. What’s the most planet-friendly thing to do with your cup? Many of us would opt for the recycling bin – but that’s often the wrong choice. In order to hold liquids, most paper coffee cups are made with a thin plastic lining, which makes separating these materials and recycling them difficult. In fact, the most sustainable option isn’t available at the trash bin. It happens earlier, before you’re handed a disposable cup in the first place. In our research on waste behavior, sustainability, engineering design and decision making, we examine what U.S. residents understand about the efficacy of different waste management strategies and which of those strategies they prefer. In two nationwide surveys in the U.S. that we conducted in October 2019 and March 2022, we found that people overlook waste reduction and reuse...

The odd headlines about little towns in the San Francisco Bay Area just keep coming. First Woodside, a tiny suburb where several Silicon Valley CEOs have lived, tried to declare itself a mountain lion habitat to evade a new California law that enabled owners of single-family homes to subdivide their lots to create additional housing. Then wealthy Atherton, with a population of 7,000 and a median home sale price of US$7.5 million, tried to update its state-mandated housing plan. Until very recently, 100% of Atherton’s residentially zoned land allowed only single-family houses on large lots. When the City Council considered rezoning a handful of properties to allow townhouses, strenuous objections poured in from such notable local residents as basketball star Steph Curry and billionaire venture capitalist Marc Andreessen. A council member argued that the town should “express and explain the specialness of Atherton … to succeed in reducing [the state’s] ex...

The blanket of wildfire smoke that spread across large parts of the U.S. and Canada in 2023 was a wake-up call, showing what climate change could feel like in the near future for millions of people. Apocalyptic orange skies and air pollution levels that force people indoors only tell part of the story, though. As global temperatures rise, fires are also spreading farther north and into the Arctic. These fires aren’t just burning in trees and grasses. New research on the exceptional Arctic fire seasons of 2019 and 2020 points to fires moving into the ground as well. These underground fires are known as “zombie fires,” and there are a number of reasons to worry about the trend. A volunteer fights ‘zombie’ peat fires in Siberia in 2020, a year when an estimated 100,000 square miles of forest, grassland and peatland burned, according to an International Association of Wildland Fire analysis. Alexa...

If you’ve ever waded into the ocean for a swim and suddenly realized that the shore is getting farther away, not closer, you may have encountered a rip current. Common at beaches worldwide, these powerful currents flow from the shore toward the sea at speeds up to several feet per second. It’s important to know what rip currents are and how to look for them, because they are a leading cause of drownings in the surf zone near shore. According to one recent estimate, rip currents have accounted for 435 drownings in the U.S. since 2017. National Weather Service offices that serve coastal communities issue forecasts that predict where and when rip currents are likely to occur. Those forecasts draw on decades of research into the physics of rip currents. Many scholars, including our research group, are finding innovative ways to discover more about rip currents – including their important roles in coastal marine ecosystems. Rip currents a...

As scorching heat grips large swaths of the Earth, a lot of people are trying to put the extreme temperatures into context and asking: When was it ever this hot before? Globally, 2023 has seen some of the hottest days in modern measurements, but what about farther back, before weather stations and satellites? Some news outlets have reported that daily temperatures hit a 100,000-year high. As a paleoclimate scientist who studies temperatures of the past, I see where this claim comes from, but I cringe at the inexact headlines. While this claim may well be correct, there are no detailed temperature records extending back 100,000 years, so we don’t know for sure. Here’s what we can confidently say about when Earth was last this hot. This is a new climate state Scientists concluded a few years ago that Earth had entered a new climate state not seen in more than 100,000 years. As fellow climate scientist Nick McKay and I recently discussed in a scientific journal art...