Shelby McClelland and Nycole Echeverria had just gotten off the plane from Denver to Katowice, Poland. The two Colorado State University graduate students had flown 16 hours to attend the annual United Nations climate pow-wow known as the Conference of Parties, or COP. Tired, they were looking for the U.S. pavilion, traditionally a prominent gathering place for Americans at these conferences.

They couldn’t find it.

Only later did they stumble upon the space, which was much smaller than in years past. The room’s diminished presence struck them as an apt metaphor for the U.S. government’s declining role in world climate affairs.

McClelland said she was “obviously” disappointed in the lack of official U.S. engagement. “But we are still in,” she said. “States like Colorado and cities are stepping up and taking on that role.”

The Trump White House did not send an official delegation to Katowice, where leaders from almost every nation are hunkering down this week and next to negotiate what’s being called the “rule book” for how to implement the Paris Agreement. That historic 2015 climate pact seeks to curb greenhouse gas emissions and halt the worst of climate change’s devastating impacts, such as rising sea levels and increasingly lethal and costly droughts and wildfires.

President Trump last year withdrew the United States from that treaty — one of President Obama’s chief foreign policy victories. Because other holdouts such as Libya and Syria have since signed on to the deal, the United States now stands as the only country in the world not on board with the global consensus reached in Paris two years ago. Back then, nearly 200 nations had agreed on the plan to rein in greenhouse gas emissions and curb global warming to within 2 degrees Celsius — a goal that President Trump never embraced because he believed it would run counter to his promise of resurrecting the fossil fuel industry in the United States.

Though officially only in Katowice as “observers,” the two CSU students — part of a larger delegation from the Fort Collins campus — quickly noticed in private conversations with other attendees that they were very worried about America’s absence from the negotiating table, given its status as the world’s largest producer of climate change-inducing greenhouse gases.

“A lot of the questions are personal: How do you feel that the U.S. isn’t participating? How does that affect your morale, your outlook?” said McClelland, a second-year Ph.D. student in CSU’s ecology program who worked for the Environmental Defense Fund after earning her undergraduate degree. “What keeps me going is that American businesses are stepping up and leading the charge.”

She mentioned Walmart’s partnership with the Environmental Defense Fund. The world’s largest retailer has made a commitment to remove one gigaton — 1 billion tons of carbon emissions — from its global supply chain by 2030.

It’s part of a larger trend: As governments endlessly quarrel about protecting their economies while simultaneously reducing their carbon emissions, industry leaders and non-governmental organizations are stepping up to the plate. Here in Colorado, for example, Xcel Energy announced this week it would commit to 100 percent carbon-free electricity by 2050.

“These non-state actors can use their economic capacities, their ability to mobilize people and information, and probably also their ability to put pressure on government in more indirect and subtle ways,” said Kenneth Shockley, an environmental ethics and philosophy associate professor and an affiliate faculty member with the School of Global Environmental Sustainability at CSU. “In sort of outdated language, they have much more of a soft power effect in the international climate arena.”

But while these industry and non-governmental organization leaders take on a much more active role in combating climate change, their voice at a gathering of nation states such as the COP is much more subtle.

“I’ve been at a number of these COPs, and you hear the side conversations, and language from these discussions finds their way into the official language of statements from countries,” Shockley said. “Because of that, there is influence to be had on the side that can be quite profound even if it is indirect and very hard to track.”

Shockley will be traveling to Katowice himself on Saturday. Given his research in environmental ethics and philosophy, he says he is mostly interested in seeing how the ultimate rule book weighs human health and well-being — measures including universal clean air and water, well babies, maternal health, longevity, educational opportunities to name a few — with the necessity to adapt to and mitigate climate change in a sustainable way.

“Countries can have different ways of focusing on their climate change responses, but for me the worry is that they are not measured financially or in terms of emissions — but in human well-being,” he said. “The ethical question here is whether or not we tie those climate action efforts to financial measures. Do we say that states have to respond to their own commitments by demonstrating financial input? Or do they have to respond by demonstrating some sort of emissions protocol?”

Amid the negotiations of those details, as well as determining a funding mechanism for adapting to climate change effects — such as improved preparation for natural disasters, infrastructure funding, data collection and an overhaul of the insurance industry — the United States is not the only country that cast a cloud of uncertainty over the climate talks. Brazil, a rising economic power and greenhouse gas emitter, has a new leader whose climate change denials echo President Trump’s.

And yet, outside the room housing top-level negotiators, signs of hope abound. And it is young people leading the charge.

The CSU delegation partnered with schools around the country, including Clark and Emory universities, to organize a side event on water and food sustainability. There, they presented CSU’s Comet Farm tool to the world.

“It is a greenhouse gas modeling tool for agricultural products, both crop and animal based,” said Echeverria, a second year master’s degree student in CSU’s greenhouse gas management and accounting program. “It uses some of the top-of-the-line modeling systems, one of which is used in the national greenhouse gas inventory for the United States. It is supposed to be a tool for farmers where they can go in and put in their farming practices, what they have done in the past, what they are doing currently, and what they might be doing in the future, and actually compare different scenarios to see what their yields might be compared to what the CO2 and methane outputs might be.”

CSU students also answered questions at a press conference entitled “Student Research and Advocacy In Climate Change.”

Members of he CSU delegation are demanding that elected officials in Washington develop a sense of urgency, one they say is sorely lacking now. The evidence, they argue, is damning. Just this week, the United Nations estimated a million lives will be lost between now and 2050 if climate change isn’t addressed. Then there is the recent Fourth U.S. Climate Assessment, which argued that without “substantial and sustained” reductions in greenhouse gas emissions, climate change will drastically hurt the U.S. economy and people across the country, while also outlining ways to adapt to our warming climate. They also point to a dire October report from the U.N. Intergovernmental Panel on Climate Change, which painted a picture of more immediate climate change consequences than previously thought and warned that an unprecedented transformation of the world economy would be necessary to avoid these damages.

“The international climate change negotiations are looking at the global level for solutions that affect every problem we face as a species and as Coloradans,” Shockley said. “It affects them by compounding and by making it more difficult to make long-term plans for things like water and agriculture and the movement of people, population growth, the changing demographics.”