News

To walk deep into the mountain forests at the doorstep of the Rocky Mountains, is to encounter the fragrant majesty of century-old ponderosa pine trees famous for lining ski slopes, National Park trails and residential neighborhoods.

Now, those iconic Colorado trees — already under strain from record heat and prolonged drought — are threatened by a rapidly growing outbreak of silent killers: the mountain pine beetle.

The size of a grain of rice, the native forest insect can attack a tree in a matter of weeks, feeding upon its critical tissues and effectively strangling it from within.

“Once a tree has been attacked, it’s likely to die,” said Sarah Hart, a forest ecologist with Colorado State University. “For managing large landscapes, we really don’t have particularly effective strategies to stop it.”

WATCH: Outbreak: Hidden Costs of the Climate Crisis at 7 and 9 p.m. ET Monday on ABC News Live PRIME, streaming on Hulu, Disney+ and ABC News apps.

More than 700,000 acres in Colorado are affected, officials say. Climate change is blamed for supercharging the emerging outbreak, with no end in sight.

Some state officials have called them “zombie forests”: ponderosa that appear to be healthy but are under existential threats from a changing climate that may result in extinction in some areas. 

“We’ve had this dearth of precipitation, above-average temperatures — It’s kind of like attacking the bank when there’s no security guard,” said Dan West, an entomologist with the Colorado State Forest Service. “These trees are standing there with not a lot of defenses.”

The cost of responding to the pine beetle outbreak, along with the financial impacts from other climate-change influenced environmental threats, are at the heart of a major Supreme Court case being argued Monday in Washington.

The City of Boulder and Boulder County, Colorado, in 2018 sued major fossil-fuel producers Exxon Mobil and Suncor Energy, seeking financial damages under state public nuisance law.

Their complaint alleges the companies “knowingly caused and contributed” to climate change by promoting fossil fuels “while concealing and/or misrepresenting the dangers,” including “devastation” to forests from an “epidemic” of mountain pine beetles.

Exxon and Suncor, which declined interviews for this story, argue in court papers that the Boulder lawsuit is based on a “dubious theory,” insisting local harms from the global phenomenon of climate change cannot be pinned on individual companies.

They’re asking the U.S. Supreme Court to toss the case out.

“National issues should be decided at the national stage, and that means Congress needs to be the one to decide what are the rules for who pays, who ultimately pays, what are standards for imposing those costs,” said Michael Williams, solicitor general of West Virginia, which has joined 25 other states backing Exxon and Suncor.

“If these suits go forward, higher gas prices are maybe the smallest consequence. I think it’s even bigger than that and you’re going to see some of these industries potentially shutter entirely,” Williams said.

Boulder city and county officials declined interview requests about the case.

Longtime Boulder resident Paul Chinowsky, a civil engineer specializing in climate impacts, said he doesn’t want the oil companies to go bankrupt but agrees they should chip in for alleged harms from their product.

“Let’s be real. We can’t live today without some level of fossil fuels, but we need regulation,” Chinowsky said in an interview in his neighborhood on the outskirts of Boulder.

“We see streets getting resurfaced. We see drainage systems getting updated, and we think of it all as, well, this is just a part of regular maintenance. Climate change is putting an accelerator on that,” he said.

Boulder and Boulder County say in court documents that they’ve spent millions on road repairs, storm drainage improvements and utility upgrades to keep pace with other environmental threats amplified by climate change.

“It’s become a significant element of the city’s budget,” said John Tayer, CEO of the Boulder Chamber of Commerce. “There are direct costs associated with the change in climate. Just everything from rising heat, which leads to greater air conditioning costs. It can slow down outdoor work because of the risk to the workforce from heat exposure. It’s across the board.”

Then there is the mountain pine beetle.

Driving from Boulder along Interstate 70 into the Front Range, rust-colored clusters of dead ponderosa pine streak the mountainsides. From above, the scale of the crisis is even more dramatic.

Bark beetles killed more than 54 million acres of pines across the West in the early 2000s, an area the size of the state of Utah. The new outbreak is expected to be much worse for communities in fire-prone areas. 

“We’ve seen a lot of sporadic wildfire activity when you have a lot of dead trees like this,” said Dan Gibbs, a veteran wildland firefighter who heads Colorado’s Department of Natural Resources, “Bark beetle-kill timber burns differently than I would say a green, alive forest.”

Teams of state foresters are scrambling to clear beetle-killed trees from hillsides near residential communities to reduce fuels for fire, one dead tree at a time. The cost to state taxpayers: $10,000 per acre, Gibbs said.

“Fire hazard, impacts to recreation, impacts to watersheds — the [dead trees have] a huge ripple effect on almost daily life of Coloradans and visitors,” he said.

If the nation’s highest court allows Boulder to sue Exxon and Suncor for damages, it won’t halt a pine beetle outbreak that state officials say will last from years to decades. But supporters of the case hope it brings increased accountability — and more funding to protect Colorado’s ponderosa pines and the people who love them.

“Oftentimes the people and the organisms that are facing the most dramatic impacts of climate change are not the ones who are benefiting from what’s causing climate change,” said Hart. “I do think that there should be greater accountability for those negative effects.”

Copyright © 2026, ABC Audio. All rights reserved.

To walk deep into the mountain forests at the doorstep of the Rocky Mountains, is to encounter the fragrant majesty of century-old ponderosa pine trees famous for lining ski slopes, National Park trails and residential neighborhoods.

Now, those iconic Colorado trees — already under strain from record heat and prolonged drought — are threatened by a rapidly growing outbreak of silent killers: the mountain pine beetle.

The size of a grain of rice, the native forest insect can attack a tree in a matter of weeks, feeding upon its critical tissues and effectively strangling it from within.

“Once a tree has been attacked, it’s likely to die,” said Sarah Hart, a forest ecologist with Colorado State University. “For managing large landscapes, we really don’t have particularly effective strategies to stop it.”

WATCH: Outbreak: Hidden Costs of the Climate Crisis at 7 and 9 p.m. ET Monday on ABC News Live PRIME, streaming on Hulu, Disney+ and ABC News apps.

More than 700,000 acres in Colorado are affected, officials say. Climate change is blamed for supercharging the emerging outbreak, with no end in sight.

Some state officials have called them “zombie forests”: ponderosa that appear to be healthy but are under existential threats from a changing climate that may result in extinction in some areas. 

“We’ve had this dearth of precipitation, above-average temperatures — It’s kind of like attacking the bank when there’s no security guard,” said Dan West, an entomologist with the Colorado State Forest Service. “These trees are standing there with not a lot of defenses.”

The cost of responding to the pine beetle outbreak, along with the financial impacts from other climate-change influenced environmental threats, are at the heart of a major Supreme Court case being argued Monday in Washington.

The City of Boulder and Boulder County, Colorado, in 2018 sued major fossil-fuel producers Exxon Mobil and Suncor Energy, seeking financial damages under state public nuisance law.

Their complaint alleges the companies “knowingly caused and contributed” to climate change by promoting fossil fuels “while concealing and/or misrepresenting the dangers,” including “devastation” to forests from an “epidemic” of mountain pine beetles.

Exxon and Suncor, which declined interviews for this story, argue in court papers that the Boulder lawsuit is based on a “dubious theory,” insisting local harms from the global phenomenon of climate change cannot be pinned on individual companies.

They’re asking the U.S. Supreme Court to toss the case out.

“National issues should be decided at the national stage, and that means Congress needs to be the one to decide what are the rules for who pays, who ultimately pays, what are standards for imposing those costs,” said Michael Williams, solicitor general of West Virginia, which has joined 25 other states backing Exxon and Suncor.

“If these suits go forward, higher gas prices are maybe the smallest consequence. I think it’s even bigger than that and you’re going to see some of these industries potentially shutter entirely,” Williams said.

Boulder city and county officials declined interview requests about the case.

Longtime Boulder resident Paul Chinowsky, a civil engineer specializing in climate impacts, said he doesn’t want the oil companies to go bankrupt but agrees they should chip in for alleged harms from their product.

“Let’s be real. We can’t live today without some level of fossil fuels, but we need regulation,” Chinowsky said in an interview in his neighborhood on the outskirts of Boulder.

“We see streets getting resurfaced. We see drainage systems getting updated, and we think of it all as, well, this is just a part of regular maintenance. Climate change is putting an accelerator on that,” he said.

Boulder and Boulder County say in court documents that they’ve spent millions on road repairs, storm drainage improvements and utility upgrades to keep pace with other environmental threats amplified by climate change.

“It’s become a significant element of the city’s budget,” said John Tayer, CEO of the Boulder Chamber of Commerce. “There are direct costs associated with the change in climate. Just everything from rising heat, which leads to greater air conditioning costs. It can slow down outdoor work because of the risk to the workforce from heat exposure. It’s across the board.”

Then there is the mountain pine beetle.

Driving from Boulder along Interstate 70 into the Front Range, rust-colored clusters of dead ponderosa pine streak the mountainsides. From above, the scale of the crisis is even more dramatic.

Bark beetles killed more than 54 million acres of pines across the West in the early 2000s, an area the size of the state of Utah. The new outbreak is expected to be much worse for communities in fire-prone areas. 

“We’ve seen a lot of sporadic wildfire activity when you have a lot of dead trees like this,” said Dan Gibbs, a veteran wildland firefighter who heads Colorado’s Department of Natural Resources, “Bark beetle-kill timber burns differently than I would say a green, alive forest.”

Teams of state foresters are scrambling to clear beetle-killed trees from hillsides near residential communities to reduce fuels for fire, one dead tree at a time. The cost to state taxpayers: $10,000 per acre, Gibbs said.

“Fire hazard, impacts to recreation, impacts to watersheds — the [dead trees have] a huge ripple effect on almost daily life of Coloradans and visitors,” he said.

If the nation’s highest court allows Boulder to sue Exxon and Suncor for damages, it won’t halt a pine beetle outbreak that state officials say will last from years to decades. But supporters of the case hope it brings increased accountability — and more funding to protect Colorado’s ponderosa pines and the people who love them.

“Oftentimes the people and the organisms that are facing the most dramatic impacts of climate change are not the ones who are benefiting from what’s causing climate change,” said Hart. “I do think that there should be greater accountability for those negative effects.”

Copyright © 2026, ABC Audio. All rights reserved.

The U.S. Supreme Court reconvenes Monday on the eve of the midterm elections to begin a new term that will confront a fresh wave of appeals from President Donald Trump and the prospect of explosive legal challenges to 2026 election results.

The first case for oral argument involves climate change and a blockbuster bid by local governments to sue energy companies for financial damages over alleged harms from fossil fuels — the first-of-its-kind dispute to reach the justices. Potentially billions of dollars are on the line.

This year the court will also decide whether states can ban semi-automatic weapons like the AR-15; deny federal ballots to voters who don’t provide proof of citizenship on state registration forms; and block religious schools from taxpayer-funded programs when they discriminate against LGBTQ+ families.

It is also considering whether to weigh in on state laws mandating display of the Ten Commandments in public school classrooms; legal shields for medical providers who mail abortion pills out of state; and, regulation of prediction markets like Kalshi and Polymarket.

These cases are not expected to be decided before the midterms in November.

“Is the court a Republican court? Is it resolving disputes in the name of justice or some broader set of principles? I think it’s a very live question,” said Genevieve Lakier, a constitutional scholar at the University of Chicago Law School. “This term, like the last, is going to provide fuel to the fire of that question.”

The justices will decide the legality of the Trump administration’s rapid deportation of immigrants to third countries — without giving them a chance to raise fears of persecution — and the indefinite detention of immigrants awaiting deportation proceedings without a chance for release on bond.

The president also has personal appeals before the court. He wants the justices to invalidate an $83 million civil judgment against him in the E. Jean Carroll defamation suit; revive a conspiracy claim against Hillary Clinton and the DNC from the 2016 campaign; and allow defamation claims against CNN from the 2020 election to go forward.

“The Supreme Court’s term is, in part, going to involve a lot of election drama,” said William Baude, a prominent conservative law professor at the University of Chicago and member of the Federalist Society. “The 2026 midterm elections are upon us, and the court has already had several pieces of litigation related to that, and has more to come at any moment.”

A majority of Americans believe that the justices are motivated mainly by politics in their decision-making and that this court — with a 6-justice conservative supermajority — rules often for Trump, a Marquette University poll found last month.

But many scholars, and the justices themselves, argue that public perception is not matched by reality.

The court ruled against Trump last term on nearly every major policy priority to reach them, striking down Trump’s sweeping global tariffs program, birthright citizenship executive order, deployment of National Guard troops to U.S. cities, removal of a Federal Reserve governor, and implementation of Postal Service mail-in ballot rules.

On dozens of other matters that reached the court on the emergency docket, however, the conservative majority has been much more deferential to the president. By one analysis, he has won about nine times out of ten.

“I don’t see this as a court that is just like, ‘We’re just going to rubber stamp what the current administration does.’ You know, quite the opposite,” Justice Elena Kagan, a member of the court’s liberal minority, told a judicial conference over the summer. “I think that that is a bad rap.”

Former Solicitor General Donald Verrilli, who served in the Obama administration, said the Court has been deliberate in asserting its independence from the president.

“It’s doing so at a time in which there really is a pretty darn serious constitutional clash going on,” Verrilli said last month. “Though, I think it’s certainly right it is not a MAGA court.”

Veteran court watchers note, however, that every term comes with surprises.

“Will the court continue to hold the line against the president’s never-ending assault on the rule of law? Will the court otherwise break down 6-3 in favor of conservative positions?” said Irv Gornstein, executive director of the Supreme Court Institute at Georgetown Law Center.

Copyright © 2026, ABC Audio. All rights reserved.

The U.S. Supreme Court reconvenes Monday on the eve of the midterm elections to begin a new term that will confront a fresh wave of appeals from President Donald Trump and the prospect of explosive legal challenges to 2026 election results.

The first case for oral argument involves climate change and a blockbuster bid by local governments to sue energy companies for financial damages over alleged harms from fossil fuels — the first-of-its-kind dispute to reach the justices. Potentially billions of dollars are on the line.

This year the court will also decide whether states can ban semi-automatic weapons like the AR-15; deny federal ballots to voters who don’t provide proof of citizenship on state registration forms; and block religious schools from taxpayer-funded programs when they discriminate against LGBTQ+ families.

It is also considering whether to weigh in on state laws mandating display of the Ten Commandments in public school classrooms; legal shields for medical providers who mail abortion pills out of state; and, regulation of prediction markets like Kalshi and Polymarket.

These cases are not expected to be decided before the midterms in November.

“Is the court a Republican court? Is it resolving disputes in the name of justice or some broader set of principles? I think it’s a very live question,” said Genevieve Lakier, a constitutional scholar at the University of Chicago Law School. “This term, like the last, is going to provide fuel to the fire of that question.”

The justices will decide the legality of the Trump administration’s rapid deportation of immigrants to third countries — without giving them a chance to raise fears of persecution — and the indefinite detention of immigrants awaiting deportation proceedings without a chance for release on bond.

The president also has personal appeals before the court. He wants the justices to invalidate an $83 million civil judgment against him in the E. Jean Carroll defamation suit; revive a conspiracy claim against Hillary Clinton and the DNC from the 2016 campaign; and allow defamation claims against CNN from the 2020 election to go forward.

“The Supreme Court’s term is, in part, going to involve a lot of election drama,” said William Baude, a prominent conservative law professor at the University of Chicago and member of the Federalist Society. “The 2026 midterm elections are upon us, and the court has already had several pieces of litigation related to that, and has more to come at any moment.”

A majority of Americans believe that the justices are motivated mainly by politics in their decision-making and that this court — with a 6-justice conservative supermajority — rules often for Trump, a Marquette University poll found last month.

But many scholars, and the justices themselves, argue that public perception is not matched by reality.

The court ruled against Trump last term on nearly every major policy priority to reach them, striking down Trump’s sweeping global tariffs program, birthright citizenship executive order, deployment of National Guard troops to U.S. cities, removal of a Federal Reserve governor, and implementation of Postal Service mail-in ballot rules.

On dozens of other matters that reached the court on the emergency docket, however, the conservative majority has been much more deferential to the president. By one analysis, he has won about nine times out of ten.

“I don’t see this as a court that is just like, ‘We’re just going to rubber stamp what the current administration does.’ You know, quite the opposite,” Justice Elena Kagan, a member of the court’s liberal minority, told a judicial conference over the summer. “I think that that is a bad rap.”

Former Solicitor General Donald Verrilli, who served in the Obama administration, said the Court has been deliberate in asserting its independence from the president.

“It’s doing so at a time in which there really is a pretty darn serious constitutional clash going on,” Verrilli said last month. “Though, I think it’s certainly right it is not a MAGA court.”

Veteran court watchers note, however, that every term comes with surprises.

“Will the court continue to hold the line against the president’s never-ending assault on the rule of law? Will the court otherwise break down 6-3 in favor of conservative positions?” said Irv Gornstein, executive director of the Supreme Court Institute at Georgetown Law Center.

Copyright © 2026, ABC Audio. All rights reserved.