TheConversation

About 400,000 years ago, large parts of Greenland were ice-free. Scrubby tundra basked in the Sun’s rays on the island’s northwest highlands. Evidence suggests that a forest of spruce trees, buzzing with insects, covered the southern part of Greenland. Global sea level was much higher then, between 20 and 40 feet above today’s levels. Around the world, land that today is home to hundreds of millions of people was under water. Scientists have known for awhile that the Greenland ice sheet had mostly disappeared at some point in the past million years, but not precisely when. In a new study in the journal Science, we determined the date, using frozen soil extracted during the Cold War from beneath a nearly mile-thick section of the Greenland ice sheet. A brief look at the evidence beneath Greenland’s ice sheet and the lessons its holds. The timing – about 416,000 years ago, with largely ice-free conditions last...

Powerful storm systems that hit the U.S. Northeast starting July 9, 2023, dumped close to 10 inches of rain on New York’s Lower Hudson Valley in less than a day and sent mountain rivers spilling over their banks and into towns across Vermont. Vermont Gov. Phil Scott said he hadn’t seen rainfall like it since Hurricane Irene devastated the region in 2011. Extreme water disasters like this have disrupted lives in countries around the world in the past few years, from the Alps and Western Europe to Pakistan, India and Australia, along with several U.S. states in 2022 and 2023. The role of climate change is becoming increasingly evident in these types of deluges. Cars were stranded in floodwater on the campus of the United States Military Academy at West Point, N.Y., on July 10, 2023. U.S. Military Academy via AP Studies by scientists around the world show that the water cycle has been inte...

“Shark!” When you hear this word, especially at the beach, it can conjure up images of bloodthirsty monsters. This summer, my colleagues and I are eager to help the public learn more about these misunderstood, ecologically important and highly threatened animals and their close relatives – rays and chimaeras. As a marine biologist focused on conserving sharks, I want people to know that an estimated one-third of them are at risk of extinction. Second, there’s an amazing variety of species in an astounding variety of shapes sizes and colors, and many of them get very little attention. Here is an introduction to a group of fishes that are at extremely high risk of extinction, and also delightfully weird: the rhino rays, named for their elongated noses. Scientists tag endangered sawfish off Florida’s west coast to identify and protect their habitats and educate the public about them. Motley shapes Rhino rays a...

Back-to-school sales are underway, and people across the country will be shopping online to fill up backpacks, lockers and closets – and they’ll be taking advantage of free returns. Making it easy for customers to return items at no cost started as a retail strategy to entice more people to shop online. But it’s getting expensive, for both retailers and the planet. In 2022, retail returns added up to more than US$800 billion in lost sales. The transportation, labor, and logistics involved raised retailers’ costs even higher. Product returns also increase pollution, greenhouse gas emissions and waste in landfills, where many returned products now end up. So how can retailers fix this problem and still provide quality customer service? We conduct research in reverse logistics, focusing primarily on the intersection of retail returns and customer behavior. Here are some insights that can help reduce the abuse of free returns and lower costs without losing...

The world’s largest shipping companies are starting to update their fleets for a greener future. Maersk received the world’s first dual-fuel methanol container ship in July 2023, and dozens more container ships that can run on alternative fuels are currently on order. The industry – responsible for about 3% of global greenhouse gas emissions, more than Canada and Ireland combined – has reasons to act and to have some confidence in its multimillion-dollar investments. On July 7, the 175 member countries of the International Maritime Organization, a United Nations agency that regulates global shipping, agreed to a new climate strategy that includes reaching net-zero greenhouse gas emissions “by or around, i.e., close to, 2050.” The strategy’s language is vague, obscure and almost noncommittal. But it points the industry toward a cleaner future. New European Union rules will also soon go into effect that will significantly raise costs for...