Trilobites: A Warning for Dogs, and Their Best Friends, in Study of Fertility

Setting aside concerns about global warming, consumers are unloading hybrid and electric vehicles in favor of bigger cars, pickups and S.U.V.s.

Trilobites: Watermelon Snow: Not Edible but Important for Climate Change
A study called for better understanding of potential effects on the climate of red algae that grows on snow in warmer months.

Q&A: Remember the Ozone Layer?
It’s still there, NASA tracks it, and scientists are still worried about it, though atmospheric levels of chemicals that damage it are slowly declining.

Take a Number: The Rising Murder Count of Environmental Activists
A new report by Global Witness puts last year’s death toll at 185, a sharp increase, with Brazil leading the way.

Mysterious Rite of Reproduction
Watch corals in their procreative dance, a spectacular event that happens once a year after the full moon.

For Coral, Mass Spawns Are the Way to Go
One researcher compares the massive, synchronized frenzy of spawning to “a wave at a stadium,” one that builds reefs and is threatened by warming seas.

A Chinese River’s Uncertain Fate
Environmentalists have defended the Nu, in Yunnan Province, for more than a decade, battling state hydropower firms intent on building dams.

China’s Last Wild River Carries Conflicting Environmental Hopes
With global temperatures rising, can a nation afford to protect a pristine waterway and forgo the building of dams as an alternative to burning coal?

Robert Paine, Ecologist Who Found ‘Keystone Species,’ Dies at 83
Dr. Paine identified certain species, like sea otters and starfish, that if removed, could disproportionately affect their ecosystems and neighboring species.

Trilobites: 12,000 Years Ago, Humans and Climate Change Made a Deadly Team
By dating bones and teeth from megafauna found in South America, researchers found that prehistoric extinctions were tied to warming and the presence of humans.

National Aquarium Plans to Create Dolphin Sanctuary
In the face of protests by animal welfare activists, the institution is discontinuing the popular tourist attraction.

Australian Rodent Is First Mammal to Go Extinct Due to Climate Change, Scientists Say
In 2014, researchers used traps and cameras to try to determine how many Bramble Cay melomys were left on a tiny outcrop in the Great Barrier Reef. They found none.

A Conversation With: Samuel K. Wasser, a Scientific Detective Tailing Poachers
A conservation biologist discusses his forensic analysis using DNA to determine the origins of seized elephant ivory.

Coal Production Plummets to Lowest Level in 35 Years
Above-normal temperatures lowered electricity demand, but tougher regulations and cheaper alternatives have hurt the industry as well.

Quick Analysis Finds Effect of Climate Change in French Floods
Using data and computer simulations, researchers say warming temperatures increased the likelihood of a deluge like the one that affected Paris.

Iceland Carbon Dioxide Storage Project Locks Away Gas, and Fast
Researchers report success in an experiment that keeps a gas tied to global warming out of the atmosphere permanently.

What in the World: A Chinese Delicacy Straight From the Swiftlet’s Mouth
Bird’s nest soup, including bird saliva, is supposed to improve the immune system, skin and sex drive. The demand means trouble for the birds themselves.

Snow in June? It’s Forecast for the Adirondacks
The higher peaks in northern New York, along with the Green Mountains in Vermont, are expecting up to two inches on Wednesday night into Thursday. This weather is unusual, but not unheard-of.

Jinshan Journal: Rare Visitor to Taiwan Is a Bird-Watcher’s Dream
The only Siberian crane ever seen in Taiwan set off a frenzy by sightseers, the hiring of a 24-hour guard and environmental efforts to welcome such migratory species.

Bleaching May Have Killed Half the Coral on the Northern Great Barrier Reef, Scientists Say
Current bleaching along the Australian reef is the most extreme ever recorded, although researchers say damage in the south appears to be less severe.

Ronald C. Davidson, Pioneer of Fusion Power, Dies at 74
During Dr. Davidson’s tenure, the Princeton Plasma Physics Laboratory made major advances toward harnessing fusion, which powers the sun.

Bleaching May Have Killed Half the Coral on the Northern Great Barrier Reef, Scientists Say
Current bleaching along the Australian reef is the most extreme ever recorded, although researchers say damage in the south appears to be less severe.

N.Y.C. Nature: Time for Horseshoe Crabs and the Shorebirds That Love Them
In late spring, the crabs return to shallow bays in and around New York to mate after a winter in deeper water. Birds that feast on their eggs wait hungrily.

Australia, Fearing Fewer Tourists, Has Chapter Taken Out of Climate Report
The report about the impact of climate change on dozens of World Heritage sites is missing a section on damage to the Great Barrier Reef.

Trilobites: Why Are Minneapolis and St. Paul So Nice? Maybe It’s the Parks
The Trust for Public Land ranked 100 urban parks systems around the country, from Minneapolis to Fort Wayne, Ind.

Report Warns of Climate Change Disasters That Rival Hollywood’s
A joint report released by Unesco, the United Nations Environment Program and the Union of Concerned Scientists detailed the threat climate change could pose to World Heritage sites on five continents.

Tornado Storms Through Kansas
At least one tornado touched down in central Kansas on Wednesday as severe weather swept through the area.

What in the World: Korean Words, Straight From the Elephant’s Mouth
While parrots are supposed to, well, parrot human speech, elephants aren’t. But don’t tell that to Koshik, an Asian elephant at a zoo near Seoul who can say at least five words.

Michael Mariotte, a Leading Antinuclear Activist, Dies at 63
Mr. Mariotte succeeded in preventing the repeal of a federal ban on interstate shipment of radioactive waste and barred the construction of new nuclear plants in Maryland and Louisiana.

Public Campaign Against Exxon Has Roots in a 2012 Meeting
A gathering held four years ago in California outlined tactics for taking on the fossil fuel industry, drawing lessons from the fight over tobacco.

Exxon Investors Seek Assurance as Climate Shifts, Along With Attitudes
A growing chorus of shareholders is worried the energy giant is not adequately preparing for tighter times in light of the Paris accord.

Tornado Sirens, an Old Technology, Still Play a Vital Role
Officials and enthusiasts believe the sirens continue to serve the public safety even with the rise of smartphones, social media and text alerts.

How Do You Move a City? Ask Kiruna, Sweden
It has nothing to do with climate change: The Arctic Circle city will be moved about two miles east so it doesn’t collapse into the mine underneath.

Opinion: Unplugging the Colorado River
Could the end be near for one of the West’s biggest dams?

New Solar Plants Generate Floating Green Power
So-called floatovoltaics are attracting international interest as a space-saving, high-efficiency alternative to land-based solar power plants.

Beyond Twitter, Donald Trump’s Views on Climate Change Are Unclear
Mr. Trump has mostly expressed his opinions on climate change and energy policy through Twitter messages. But more of his views are starting to emerge.

State Officials Investigated Over Their Inquiry Into Exxon Mobil’s Climate Change Research
Some members of Congress have demanded access to communications since 2012 between state attorneys general and climate change activist groups.

Australia to Lay Off Leading Scientist on Sea Levels
The scientist, John Church, confirmed that he was one of 275 scientists that an Australian science agency said would be dismissed.

Humans and Mastodons Coexisted in Florida, New Evidence Shows
The discovery of an unmistakable human artifact proves that humans colonized northern Florida by 14,550 years ago.

N.Y.C. Nature: When Caterpillars Move In, the Yellow-Billed Cuckoo Feasts
An upside to the onslaught of Eastern tent caterpillars, whose webby bivouacs festoon black cherry trees, is the chance to watch the birds that eat them.

Volcanic Eruption in Costa Rica
Infrared camera footage captured the Turrialba Volcano erupting on Wednesday. The volcano is located about 30 miles from Costa Rica’s capital, San José.

Europe Trails U.S. in Cutting Air Pollution, W.H.O. Says
Air quality readings from 3,000 cities in 103 countries found that more than 80 percent of people in those cities were exposed to dangerous particle levels.

Researchers Aim to Put Carbon Dioxide Back to Work
Scientists are working on ways to recycle and reuse carbon dioxide, rather than storing it underground, to fight climate change.

The Science of Fat: After ‘The Biggest Loser,’ Their Bodies Fought to Regain Weight
Contestants lost hundreds of pounds during Season 8, but a study of them helps explain why they could not keep all of that weight off.

Wait, What’s That Noise? Cicadas, the New Batch, to Sound Siren Song in 5 States
Everything you need to know about the insects set to ascend from the ground after 17 years and seek mates with singing that sounds like a tiny maraca.

China Curbs Plans for More Coal-Fired Power Plants
The country, the world’s biggest emitter of greenhouse gases, halted plans for new coal-fired plants and postponed building of some already approved.

Gorillas in Danger of Extinction
The population of the world’s largest primate, the Grauer’s gorilla, has plummeted 77 percent over the last 20 years, with fewer than 3,800 remaining.

Walter Kohn, Nobel-Winning Scientist, Dies at 93
A chemist and physicist who fled Nazi-occupied Vienna as a child and built a distinguished academic career in the United States, becoming an American citizen in 1957.

Carbon Pricing Becomes a Cause for the World Bank and I.M.F.
To ensure that the Paris agreement on climate change works, two global lenders have begun pressing national governments to ensure that polluters pay for the carbon dioxide they emit.

Opinion: Lessons From Underwater Miami
Clues to the future from an era when hippos splashed in the Rhine.

Mushroom Suits, Biodegradable Urns and Death’s Green Frontier
A growing number of products rely on sleek design and online publicity to get people comfortable with an environmentally friendly death.

Trilobites: Celebrate Earth Day With a 4,800-Year-Old Tree (If You Can Find It)
The exact location of Methuselah, a Great Basin bristlecone pine commonly known as the world’s oldest tree, is kept a secret.

Letter of Recommendation: Letter of Recommendation: AstroTurf