Nate Rott

Smoke from the ongoing firestorm in Australia is obscuring skies halfway around the world. Satellite images from the National Oceanic and Atmospheric Administration show a haze from the deadly fires spreading over South America. The swirling plume is nearly the size of the continental United States.

All fires emit smoke — a combination of thousands of compounds, including climate-warming greenhouse gases. But the sheer scale of the emissions, and the severity of the fires causing them, are concerning climate scientists around the world.

On "good" bad days, the shells lie open at the bottom of the river, shimmering in the refracted sunlight. Their insides, pearl white and picked clean of flesh, flicker against the dark riverbed like a beacon, alerting the world above to a problem below.

Updated at 8:59 p.m. ET

The Trump administration is proposing to exempt Alaska's Tongass National Forest from long-standing protections against logging and development, opening the door for potential timber harvesting on 165,000 acres of old-growth forest.

The warnings come with unsettling regularity:

Climate change threatens 1 million plant and animal species.

Warmer oceans could lose one-sixth of their fish and other marine life by the end of the century.

Angel Portillo doesn't think about climate change much. It's not that he doesn't care. He just has other things to worry about. Climate change seems so far away, so big.

Lately though, Portillo says he has been thinking about it more often.

Standing on the banks of a swollen and surging Arkansas River, just upriver from a cluster of flooded businesses and homes, it's easy to see why.

"Stuff like this," he says, nodding at the frothy brown waters, "all of the tornadoes that have been happening — it just doesn't seem like a coincidence, you know?"

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.

Scott Pruitt, the former head of the Environmental Protection Agency, and his staff spent roughly $124,000 in excessive travel costs during a ten-month period, according to a new report from EPA's internal watchdog.

Up to 1 million of the estimated 8 million plant and animal species on Earth are at risk of extinction — many of them within decades — according to scientists and researchers who produced a sweeping U.N. report on how humanity's burgeoning growth is putting the world's biodiversity at perilous risk.

The Trump administration is postponing controversial plans to greatly expand oil and gas drilling off of the nation's coasts, following a recent setback in court and months of pushback from coastal communities.

Last month, a federal judge in Alaska ruled that President Trump exceeded his authority when he signed an executive order to lift an Obama-era ban on oil and gas drilling in parts of the Arctic and Atlantic oceans.

New Mexico, a poor but fossil fuel-rich state, is aiming to make itself a national leader in the fight against climate change.

Lawmakers passed ambitious legislation this week that will reshape the state's energy sector by mandating that the state's publicly regulated utilities get all of their electricity from carbon-free sources like solar and wind by 2045.

Trina Jo Bradley squints down at a plate-sized paw print, pressed into a sheet of shallow snow.

She reaches down with fingers outstretched, hovering her palm over a sun-softened edge. Her hand barely covers a third of the track.

"That's a big old foot right there," she says, with a chuckle. "That's the one where you don't want to be like: 'Oh! There he is right there!"

Bradley, like many ranchers, applies a wry sense of humor to things that feel out of her control.

In Tennessee, a wildland fire training academy was canceled. In California and the southeast U.S., forest cleanup and fuel mitigation projects, intended to reduce the risk of catastrophic wildfire, are being postponed. In Montana, a workshop designed to help forest managers better prepare communities for fire risk has been scuttled.

As the partial government shutdown stretches into its third week, becoming the longest shutdown in U.S. history, hundreds of thousands of federal workers remain furloughed.

Updated at 6:40 p.m. ET

Ryan Zinke is out as secretary of the interior.

Zinke will be leaving the Trump administration at the end of the year; his successor is expected to be announced next week.

On Saturday morning, President Trump tweeted that Zinke is leaving after serving for almost two years. He said Zinke has accomplished much during his tenure and thanked him for his service.

The Trump administration has released plans to lift or alter habitat protections for the greater sage grouse across millions of acres of Western land.

The long-anticipated proposals, released Thursday by the Bureau of Land Management, would revise a sweeping conservation effort made under the Obama administration, allowing for more development in the chicken-sized bird's vast habitat.

About 150 steps from John Imperato's Southern California home, pavement gives way to an ever-shrinking stretch of soft sand.

Imperato lives in Del Mar, a small, affluent town just north of San Diego. He spent his life savings to live here. He wanted to raise his son like he grew up, withing walking distance of the sea.

Del Mar is a picturesque place; its name means "of the sea," in Spanish.

That's becoming increasingly true.

There's a cycle that starts when the snow melts and the earth thaws high in Colorado's Rocky Mountains. It's a seasonal cycle based on timing and temperature, two variables that climate change is pushing increasingly out of sync.

To the outsider, it can be hard to see: Plants still grow, flowers bud, bears awake, and marmots breed. Broad-tailed hummingbirds still trill around a landscape that evokes the opening scene of The Sound of Music, with flowery meadows and granite peaks.

The images from the eruption of Kilauea are breathtaking. Lava is gushing from cracks in the earth, spraying — at times — more than 200 feet in the air. Eruptions from the Halema'uma'u crater continue to punch plumes of gas and ash into the Hawaiian sky.

For those living in the southeast corner of the Big Island, the eruption is devastating. Thousands have been evacuated, as rivers of lava slowly burn their way down the flanks of the long-active volcano, consuming homes and blocking roads.

As Environmental Protection Agency chief Scott Pruitt has moved to roll back a sweeping array of Obama-era regulations he's relentlessly cited his goal of providing "regulatory certainty."

In his first address to career employees last year he told the gathered room at the EPA, "Regulators exist to give certainty to those that they regulate. Those that we regulate ought to know what we expect of them, so that they can plan and allocate resources to comply."

The Interior Department is abandoning a plan to more than double entrance fees to some of the country's most popular national parks, opting instead to apply a "modest" fee increase to 117 parks beginning this summer in an effort to raise funds for park maintenance.

The announcement Thursday comes after an outcry from the public and from lawmakers, who were concerned that certain large increases that were initially proposed would price people out of the nation's parks.

The Trump Administration today moved to weaken fuel economy standards for automobiles, saying the current ones are inappropriate and wrong.

The long-anticipated move is a win for auto manufacturers, which had lobbied for lower fuel-economy standards. It's also a rejection of one of former President Barack Obama's biggest efforts to combat climate change by curbing greenhouse gas emissions.