The Danish capital is moving rapidly toward a zero-carbon future, as it erects wind farms, transforms its citywide heating systems, promotes energy efficiency, and lures more people out of their cars and onto public transportation and bikes.

Fishways on rivers in the U.S. Northeast are failing, with less than 3 percent of one key species making it upriver to their spawning grounds, according to a new study. The researchers’ findings provide a cautionary tale for other nations now planning big dam projects.

Ontario is on the verge of becoming the first industrial region in North America to eliminate all coal-fired electrical generation. Here’s how Canada’s most populous province did it — and what the U.S. and others can learn from it.

A new census found this winter’s population of North American monarch butterflies in Mexico was at the lowest level ever measured. Insect ecologist Orley Taylor talks to Yale Environment 360 about how the planting of genetically modified crops and the resulting use of herbicides has contributed to the monarchs’ decline.

The world’s largest living species, native to California’s Sierra Nevada, faces a two-pronged risk from declining snowpack and rising temperatures. The threat to sequoias mirrors a growing danger to trees worldwide, with some scientists saying rapid warming this century could wipe out many of the planet’s old trees.

Stanford University scientist Barbara Block heads a program that has placed satellite tags on thousands of sharks, bluefin tuna, and other marine predators to better understand their life cycles. Now, using data available on mobile devices, she hopes to enlist public support for protecting these threatened creatures.

U.S. climate activists have launched a movement to persuade universities, cities, and other groups to sell off their investments in fossil fuel companies. But while the financial impact of such divestment may be limited, the campaign could harm the companies in a critical sphere — public opinion.

Matthew Tejada is taking over the EPA’s Office of Environmental Justice after helping low-income communities in Houston fight air pollution in their neighborhoods. He talks to Yale Environment 360 about how his work in Texas prepared him for the challenges of his new post.

By analyzing mitochondrial DNA, scientists now can make more accurate estimates of the numbers of individual species that existed centuries ago. What does it tell us about our impact on the natural world and about our own future?

New research shows that scientists have significantly overestimated the damage that logging in tropical forests has done to biodiversity, a finding that could change the way conservationists think about how best to preserve species in areas disturbed by humans.

Better Place was touted as one of the world’s most innovative electric vehicle start-ups when it launched six years ago. But after selling fewer than 750 cars in a major initiative in Israel and losing more than $500 million, the company’s experience shows that EVs are still not ready for primetime.

Maria Damanaki, Europe’s crusading fisheries minister, is making major headway in changing a cozy, “old boys” network that over-subsidized the European fishing industry and brought about the severe overfishing of the continent’s marine bounty.

The Netherlands’ system of dikes and sea gates has long been the best in the world. But as the country confronts the challenges of climate change, it is increasingly relying on techniques that mimic natural systems and harness nature’s power to hold back the sea.

With activists killed in Brazil, Cambodia, the Philippines, and elsewhere, 2012 may have been the worst year yet for violence against those working to protect the environment. So far, little has been done to halt this chilling development.

Republican Bob Inglis’ statement that he believed in human-caused climate change helped cost him his seat in Congress. In a Yale Environment 360 interview, Inglis explains why he is now trying to persuade his fellow conservatives that their principles can help save the planet.

One of the few potential advantages attributed to soaring carbon dioxide levels has been enhanced crop growth. But in an interview with Yale Environment 360, botanist Stephen Long talks about his research showing why rising temperatures and an increase in agricultural pests may offset any future productivity gains.

In a new paper, the world’s leading polar bear scientists say the time has come to consider drastic measures to save these iconic animals, including supplemental feeding by humans during ice-free periods and relocating more southerly populations to the High Arctic.

Scientists are only beginning to understand the impacts of mercury contamination on birds, fish, and other wildlife populations. But what they are finding is alarming — even low levels can cause harm, and chronic exposure has unexpected and troubling effects.

Urban stormwater runoff is a serious problem, overloading sewage treatment plants and polluting waterways. Now, various U.S. cities are creating innovative green infrastructure — such as rain gardens and roadside plantings — that mimics the way nature collects and cleanses water.

After more than four decades as a leading environmentalist, Gus Speth is disillusioned with what has been accomplished. What’s needed now, he says in an interview with Yale Environment 360, is a transformative change in America’s political economy that will benefit both society and the planet.

The Atlantic Canyons off the Northeastern U.S. plunge as deep as 15,000 feet and harbor diverse and fragile marine ecosystems. Now, the Obama administration’s plans to consider offshore oil and gas exploration in the canyons is troubling conservationists.