Here at Colorado’s premier, research-based, relentlessly intellectual environmental science and health newsletter, we’ve been lying awake at night pondering our state’s biggest crisis:
Who took Daisy and Thunder?
Sheeple, wake up! There are 180 cattle missing from the Montrose area. Do you even realize that’s a short UFO flight from Crestone? Have we checked the Sand Dunes? Were they a casualty of the failed Kroger/Albertson’s merger? Did anyone check whether Western Slope counting machines were tampered with?
We are currently negotiating with editors for luxury accommodations in Telluride to adequately monitor this developing situation. In the meantime, check in with Olivia Prentzel’s coverage and rest assured we will not rest until Bessie and Stormy are accounted for. It’s no joke to the owners — the wandering calves are worth $1,000 to $2,000 each.
Free the ruminants before the UFOs make them mutants!
On to the news, and there’s lots of it …
TEMP CHECK
CLIMATE
Denver adapts greenhouse gas rules for big building owners. They’re still mad.

To be fair, landlords are never too keen on being told what they can and can’t do with their properties.
Even in good times, owners and managers of big buildings are wary of new laws that raise their costs, whether adding recycling options for apartments or updating fire codes or telling them their lawn mowing equipment must be cleaner.
So it’s no surprise Colorado and Denver’s biggest property owners would be fighting a truly revolutionary series of mandates to how they do business, in the form of greenhouse gas reduction and energy efficiency standards from state and city governments.
Similar to a Colorado state law covering large buildings statewide, Denver in 2021 passed “Energize Denver,” with a target 30% cuts to Denver buildings’ “energy use intensity” by 2030 and net zero on carbon from building energy in 2040. The city law, which started taking effect in 2023, required owners of large buildings to get extensive energy audits and come back with plans to reduce energy use and carbon output against a 2021 benchmark.
Though property owners had input all along the way at both the state and city level, they started legal pushback against the rules as soon as they went into effect.
“If you’ve got a multifamily apartment in the city of Denver that say has 200 or 250 units, and it’s going to cost you $10,000 to $15,000 per unit to bring them up to the standards that Energize Denver has, that’s quite a sum of money you’re spending on a property that you hadn’t intended,” said Dennis Supple, president of the Denver chapter of the International Facilities Management Association. “Rents are already high enough.”
Denver officials agreed to keep negotiating with the property owners, and have now issued a revised set of rules they say eases the timelines for the energy audits and the required targets.
Denver leaders know property owners have major challenges, including vacant downtown buildings cleared out by commuters fleeing, higher property taxes and more, said Sharon Jaye, policy manager for the Denver Office of Climate Action, Sustainability and Resilience.
“Your building is half vacant, so you literally don’t have the cash flow to be able to do an energy audit at this time,” Jaye said, as an example. “And so what we would do is get them into the alternate timeline adjustment and work with them on a one-year rotation and say, we’ve got you approved. You’re not going to see any penalties in the meanwhile, we’ll check in with you in a year, see how you’re doing.”
But in tweaking the rules, Denver is also underlining the importance of the original law: 49% of greenhouse gases coming from Denver are attributed to the energy used in big buildings, said CASR executive director Elizabeth Babcock. Cutting energy use isn’t just good for the environment and the climate, Babcock said, it’s also good business: Many clients want greener buildings, and an efficient building is cheaper to own.
Sustainability and affordability are not mutually exclusive, CASR says.
The property owners and managers are saying to Denver, thanks for working on it, but that’s not good enough. Supple said Denver’s proposed rule changes are not being written into the past ordinance, and could be changed by a new mayor or council. They also rely too heavily still on penalties and coercion, the owners say.
“We’re all trying to be good partners. It’s not like we drive down the street and throw used motor oil out of our car as we’re going,” Supple said. “We try to keep our buildings as efficient as possible, because that saves me money to spend more money on the things I’d like to spend it on. But when you have government overreach coming in and saying, ‘We don’t like this, you’re going to do this,’ and they have not taken into account what the capital expenditure is on doing that, that’s when we have a problem.”
These conflicts will only get harder, as a host of climate rules across multiple sectors of the economy kick in and business owners start seeing the bills come due. Read more about the disputes over building efficiency in coming days at ColoradoSun.com.
CLIMATE
These gorgeous photos will make you even more ambivalent about Lake Powell.

Elliot Ross has captured the tantalizing promise of nature regenerating when Lake Powell recedes and Glen Canyon’s original fauna and vistas are reborn.
But his mesmerizing photographs, on display now in the underappreciated art galleries tucked into Denver Botanic Gardens, also leave viewers with an unmistakable sense of “be careful what you wish for.”
The artificial reservoir of Lake Powell in southern Utah reached record lows during 2022’s megadrought, uncovering lost side canyons and giving native plants time to reclaim the sandy shores. If Western snows pile up again and drought recovery continues, all that Fort Collins-based Ross reveals in his photos will be back under water again.
We said it was a beautiful art show. We didn’t say it was simple.

Could we ever afford to live without Glen Canyon Dam and the lake it holds back, the second largest reservoir in the U.S. after downstream Lake Mead? Ross’ photos, titled “Geography of Hope,” will set some to dreaming and others to debating.
You see sandbars dotted with orange lake buoys. Goosenecks flooded out of view since Powell first started filling in 1963. Houseboats huddling together against a storm of climate change on what’s left of the pool at Bullfrog marina.

Powell has always been saturated with contradiction. Damming the Colorado River at Page, Arizona, flooded out of view some of the world’s greatest canyon country. Yet it saved other canyons from similar dam destruction, in a West determined to create massive reservoirs serving seven states.
And creating a floater’s paradise allowed millions of Americans to see canyon country and appreciate open space, even if that scenery was often viewed through beer goggles.
So what should happen next at the home of the Rincon and Escalante and Rainbow Bridge? Contemplate the future of these Western icons in the quiet spaces at the botanic gardens, with the Ross exhibit open through Feb. 2.
CLIMATE
A rare Rio Grande trout is not rare enough to be an extinction threat

26
Number of years since an environmental group first sought Endangered Species Act protections for the Rio Grande cutthroat
It’s a reality of environmental news that admittedly defies assumptions: State and local natural resources officials often fight very hard against naming a new endangered species, saying they would rather keep local control in protecting wildlife.
They say that while they are equally invested in stopping extinctions, imposing a demanding federal regime of actions under the Endangered Species Act is not the answer.
Efforts in Colorado and New Mexico to preserve and grow the rare Rio Grande cutthroat trout were rewarded this week with exactly that kind of nod to local efforts. The U.S. Fish and Wildlife Service said a yearslong review showed the trout with the striking fire-red belly does not need Endangered Species Act protection.
“The Service concluded that the Rio Grande cutthroat trout is not in danger of extinction or likely to become so in the foreseeable future,” the Fish and Wildlife Service said. In making the announcement, federal officials specifically called out the success of “ongoing multi-partnership efforts” by a host of local governments and nonprofits in the West to support trout populations.
Sun reporters Kevin Simpson and Lucy Haggard wrote about the Rio Grande cutthroat in 2020, because of course they did — long, interesting stories about fish are what we do. Who knew, before they attacked the problem, that saving one of 14 subspecies of cutthroat was such an involved and controversial process.
At the time, Simpson and Haggard were detailing angry local reactions, in the Wet Mountain Valley and San Luis Valley, to state wildlife officers poisoning other fish in beloved local creeks, in order to clear the way for the Rio Grande cutthroat’s reentry.
They wrote about how those wildlife officials can themselves get frustrated with local reactions, when they’ve tried to explain the complex problem over and over again in public meetings that not enough people attend.
“It’s something we need to do,” said John Alves, the Durango-based senior aquatic biologist for Colorado Parks and Wildlife’s Southwest Region, when The Sun last wrote about the fish. “With only 11% of its historic range left, the Rio Grande cutthroat trout is always susceptible to petitions to list it as endangered,” as well as to threats like wildfires. “It’s a constant process for us.”
One group that will be unhappy about the new Fish and Wildlife Service decision on the Rio Grande cutthroat is the nonprofit Center for Biological Diversity, which first started pushing for endangered species designations for the fish in 1998.
The CBD told the Sun in 2020 that while they hadn’t won federal protections yet, they were glad state and local officials had been working hard to help the fish.
“We haven’t succeeded in putting them on the protected list, but we’ve pressured the state to do more for them, which is a benefit for the species,” a CBD official said.
Now, the CBD is plotting its next moves after federal protection has been formally denied. Environmental groups could appeal, said CBD endangered species specialist Noah Greenwald, but after 25 years the process “feels like a treadmill.”
“This species needs regulatory protection. It needs Endangered Species Act protection, and the Fish and Wildlife Service is, just from my view, ignoring the science,” Greenwald said Tuesday. Colorado and New Mexico have made some good efforts on the Rio Grande cutthroat, but their numbers and range have not improved much at all over decades, he said.
Cutthroats get pushed out by hardier nonnative game trout like rainbows and browns, Greenwald added. But there are many reasons to fight for the Rio Grande cutthroat, because cutthroats are the true native trout for Colorado and ecosystems built up around their behavior, he said.
Plus, even if you just want to protect the Rio Grande trout because it’s got a bright red belly, that’s a good thing, he said.
“Our world is becoming homogenized, and so the fact that it’s beautiful, to me, is not insubstantial,” Greenwald said. “Part of the magic of the world is disappearing.”
Read more about the cutthroats, and better Endangered Species Act news for the popular monarch butterfly, in coming days at ColoradoSun.com.
MORE CLIMATE NEWS
CHART OF THE WEEK

Like an increasing number of other climate disasters, the one-unthinkable vision of no ice left around the North Pole is no longer a fictional Hollywood scenario. It’s possible within three years, according to scientists at CU Boulder and other institutions.
“The first summer on record that melts practically all of the Arctic’s sea ice, an ominous milestone for the planet, could occur as early as 2027,” according to a well-done science story summary by Yvaine Ye in CU Boulder Today. Simulations put the likely range of an ice-free year from nine to 20 years after 2023, with outside chances of it happening as early as 2027.
CU Boulder climatologist Alexandra Jahn worked with the University of Gothenburg in Sweden on computer modeling. They report that under global warming, Arctic sea ice is disappearing at the rate of more than 12% each decade. The standard for “ice-free” is less than 1 million square kilometers of Arctic ice, according to the research published in a December issue of “Nature Communications.”
“The first ice-free day in the Arctic won’t change things dramatically,” said Jahn, associate professor in the Department of Atmospheric and Oceanic Sciences and fellow at CU Boulder’s Institute of Arctic and Alpine Research. “But it will show that we’ve fundamentally altered one of the defining characteristics of the natural environment in the Arctic Ocean, which is that it is covered by sea ice and snow year-round, through greenhouse gas emissions.”
The map above is not from their report, but is a visceral look from NOAA at how bad things have been lately for Arctic sea ice. The outlines show where the Arctic should be at the late-summer ebb and the winter peak, in an average year. The reality, shown in the shaded area, is a major retreat of icy conditions driven by climate change.
Thanks for joining us today, and thanks for all your support on Colorado Gives Day. We will do our best to reward your trust with the latest in environment, science and health news. Plus missing-cattle updates. We will divine all the news that is bovine.
— Michael & John

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