Rebecca Hersher

Lead-based paint was extremely popular in the early and mid-20th century — used in an estimated 38 million homes across the U.S. before it was banned for residential use in 1978.

The firefighters came on Monday. They went up and down the halls, knocking on every apartment in the six-story Ansonborough House building in downtown Charleston, S.C., and leaving notices on the doors of those who didn't answer: This area is under mandatory evacuation.

The manager of the building heeded the warning and left a note on the window in the lobby explaining that the building would not be staffed all week.

If you want to know what climate change will look like, you need to know what Earth's climate looked like in the past — what air temperatures were like, for example, and what ocean currents and sea levels were doing. You need to know what polar ice caps and glaciers were up to and, crucially, how hot the oceans were.

Humans must drastically alter food production to prevent the most catastrophic effects of global warming, according to a new report from the United Nations panel on climate change.

The panel of scientists looked at the climate change effects of agriculture, deforestation and other land use, such as harvesting peat and managing grasslands and wetlands. Together, those activities generate about a third of human greenhouse gas emissions, including more than 40% of methane.

It technically began last fall when Hurricane Florence swelled the Ohio River, but really it was all the unnamed storms that came after it — one after another after another, bringing rain on rain on rain across the central U.S. until the Mississippi River hit flood stage this winter.

Much of the Mississippi, and the massive tributaries that feed it, stayed flooded until June. That meant more than 140 days of cascading disasters for hundreds of small towns from Minnesota to Louisiana and catastrophic damage to ranch and farm communities that dot the Mississippi's swollen branches.

The global shipping industry is enormous — thousands of ships carry billions of dollars of goods each year across nearly every ocean on the planet.

People across southern Louisiana are spending the weekend worried about flooding. The water is coming from every direction: the Mississippi River is swollen with rain that fell weeks ago farther north, and a storm called Barry is pushing ocean water onshore while it drops more rain from above.

It's a situation driven by climate change, and one that Louisiana has never dealt with, at least in recorded history. And it's raising questions about whether New Orleans and other communities are prepared for such an onslaught.

Sea levels are rising, and that is sending more ocean water into streets, sewers and homes. For people who live and work in coastal communities, that means more otherwise-sunny days disrupted by flooding.

Updated at 9:34 a.m. ET

If you are neurotic and anxious, your dog may be feeling the stress, too.

Updated at 9:35 p.m. ET

The Arkansas River just keeps rising. The usually placid tributary of the Mississippi has become a bloated torrent carrying entire trees downstream, drowning riverfront property and halting commerce for hundreds of miles.

Federal weather forecasters are predicting a "near normal" number of storms this hurricane season, which runs from June 1 through November 1.

Between nine and 15 named storms, including includes tropical storms, are predicted to form in the Atlantic this year, said Neil Jacobs, acting administrator of the National Oceanic and Atmospheric Administration.

The Mississippi River is rising again as torrential rain falls across much of the Midwest. It's the latest in a series of storms that have flooded major cities and small communities along the length of the Mississippi and Missouri rivers on and off for more than a month.

Scientists are ramping up research on the possible health effects of a large group of common but little-understood chemicals used in water-resistant clothing, stain-resistant furniture, nonstick cookware and many other consumer products.

Detecting very small earthquakes is notoriously difficult. The churning of the ocean, a passing car or even the wind can feel a lot like a minor quake to the sensors that blanket seismically active parts of the U.S.

That's a problem for scientists who rely on data about all the earthquakes in a region to study what triggers the biggest, most destructive ones.

Hurricane Maria was the rainiest storm known to have hit Puerto Rico, and climate change is partly to blame, according to a new study.

The worst rain fell in the mountainous central part of Puerto Rico, from the northwest to the southeast. That part of the island is rainy under normal conditions. In an average year, it gets more than 150 inches of rain.

When Maria hit in 2017, it dropped nearly a quarter of that annual rainfall in just one day.

An hour south of Charlotte, N.C., two forks in the road beyond suburbia, a freshly constructed house sits in a wind tunnel waiting to be set on fire.

To the left of the house is a brick wall with a hole in the middle, made by a 2-by-4 propelled at 70 miles per hour.

In front of the house is a metal staircase five stories tall. At the top are the hail guns.

More than 100 fans begin to turn, slowly at first and then faster. The ember generators flicker on. The fire is about to begin.

Several members of a powerful science panel for the Environmental Protection Agency expressed doubt at a hearing Thursday about the long-established scientific consensus that air pollution can cause premature death.

The panel was meeting to consider recommendations that would fundamentally change how the agency analyzes the public health dangers posed by air pollution and could lead to weaker regulation of soot.

When a storm gets very intense very quickly, it gets a very special, very scary name: bomb cyclone.

And just such a storm has arrived in the central U.S.

If they had known, they never would have bought the house on Bayou Glen Road. Sure, it was a beautiful lot, tucked in a bend of the creek, backyard woodsy and wild, the neighbors friendly and the street quiet. A little piece of nature just 20 minutes from downtown Houston. It was exactly what John and Heather Papadopoulos — recently married, hoping to start a family — were looking for in 2007. They didn't think much about the creek that ran along their yard, aside from appreciating the birds it attracted to the neighborhood.

The skin lesions are the first sign that something is wrong. Then limbs fall off and the body disintegrates, collapsing in on itself as it liquefies. In the end, what was once a sea star is only a puddle on the ocean floor.

Since 2013, sea star wasting disease has killed so many starfish along the Pacific Coast that scientists say it's the largest disease epidemic ever observed in wild marine animals. Where there used to be dozens of stars, scuba divers now report seeing none.

Nearly 200 countries have agreed on a set of rules to reduce global greenhouse gas emissions, a crucial step in implementing the landmark 2015 Paris climate agreement.

The rules describe in detail how countries will track their emissions and communicate with each other about their progress in the coming years and decades. But it stops short of committing them to the more ambitious emissions reductions necessary to slow climate change.

Leaders from nearly 200 countries, including the United States, are at a big climate conference in Poland this week. They are struggling to agree on rules for how to meet their national promises to reduce greenhouse gas emissions under the Paris climate agreement of 2015. The official U.S. position is making it difficult.

As the international climate summit in southern Poland enters its second and final week, most countries agree on the basic scientific facts: greenhouse gasses are causing climate change, and every country is feeling its effects.

But the United States, under the leadership of President Trump, has taken a different view. The administration questions the overwhelming scientific evidence suggesting that human activity is causing the climate to warm. As a result, the U.S., which has been a leader in past negotiations, is playing unpredictable role in this year's summit.

For the next two weeks, leaders from around the world are attending a major climate conference in Poland. They will talk about how to reduce global greenhouse gas emissions and how to support those communities that are already being affected by climate change.

Climate change is already causing more frequent and severe weather across the U.S., and the country is poised to suffer massive damage to infrastructure, ecosystems, health and the economy if global warming is allowed to continue, according to the most comprehensive federal climate report to date.

In October 2017, Drew Wynne collapsed inside a walk-in refrigerator at his coffee business in North Charleston, S.C. By the time his business partner found him crumpled on the floor, Wynne was dead. He had suffocated on a chemical called methylene chloride.

Carmen Lugo has lived in Puerto Rico her whole life, and her whole life she has feared the water that comes out of her tap.

"When I was a child, we used filters," she says, leaning on the doorjamb with her 11-year-old in front of her and two teenage sons sleepy-eyed behind her on a morning in July.

"The water here," she says, pausing as she purses her lips in a tight smile. She chooses her words carefully. "We want to be in good health," she finally says. "My husband, he buys water from the Supermax," referring to a local grocery store.

Lawanda Jones' house near Myrtle Beach, S.C., is next to a large, lovely tree. Earlier this week, as Jones listened to the evacuation orders and hurricane warnings piling up, she looked at that tree and thought: what if it falls?

On Friday afternoon, Jones stood outside Conway High School, a Red Cross shelter and, on drier days, home of the Tigers. She and her family have been staying at the shelter since Tuesday and, although it's crowded and difficult to sleep among strangers, she said she's glad she evacuated early.