- This week, the UN Environment Program launched the Global Environment Outlook 7 (GEO-7), a stark assessment that comes on the heels of US President Donald Trump’s dismissal of climate change as a “con job.”
- In this context, Mongabay interviewed GEO-7 co-chair Sir Robert Watson about what to tell a political leader who rejects the science.
- “The evidence is definitive,” says Watson, who argues that countries must rethink their economic and financial systems and that science must be heard in the rooms where power lies.
When U.S. President Donald Trump addressed the United Nations General Assembly in late 2025 and dismissed climate change as a “con job”, the scientific community reacted with alarm. Months earlier, The Guardian had reported that his anti-climate agenda could result in 1.3 million additional deaths globally. Prior to that, in August, CNN documented how scientists were coordinating to counter Trump’s attempts to erase credible climate research from the record.
The news was emblematic of a wider trend: The rapid spread of climate disinformation, a resurgence of greenwashing and a global political environment increasingly hostile to science — even as emissions rise, biodiversity collapses and pollution reaches lethal levels.
Against that backdrop, the U.N. Environment Program launched another report, which it called a flagship environmental assessment — the Global Environment Outlook 7 (GEO-7) — in Nairobi on Tuesday. Authored by 287 scientists from 82 countries, the report paints a stark picture: Greenhouse gas emissions continue climbing, 20-40% of global land is degraded, pollution kills 9 million people a year and 1 million species face extinction if current trends continue.
Among the co-chairs of GEO-7 is Sir Robert Watson, one of the world’s most respected environmental scientists and a former chair of the IPCC, the U.N.’s top climate science body. In many ways, he has spent his career trying to ensure science informs political decisions. Watson was in Nairobi this week for the launch of the GEO-7.
So, what would he tell a political leader who rejects the science entirely? Mongabay asked him.
“The evidence is definitive,” he said.
“If you had someone like President Trump or another president who does not believe in science,” Mongabay asked, “what would you tell them?”
Watson didn’t hesitate. “I’d simply point and say to him, the evidence is definitive. We’re changing our environment and there are cost-effective ways to save our environment.”
It is an answer that lands sharply in an era of manufactured doubt, designed confusion and deliberate politicization of science.
But to understand why Watson believes the evidence is “definitive,” one must understand what GEO-7 released this week in Nairobi actually says.
The report warns that the planet is on track for deeper climate shocks, accelerating biodiversity loss, worsening land degradation and deadly pollution — unless countries drastically transform how economies are powered, fed and governed.
Asked for the report’s headline message, Watson framed it simply:
“The environment is changing, not just climate change, but loss of biodiversity, pollution, land degradation. All of these issues are getting worse — and they are all interconnected and must be addressed together.”
The GEO-7 findings echo dozens of other scientific assessments released in the past five years — on wetlands, chemicals, emissions, tipping points and biodiversity. UNEP’s own Adaptation Gap Report warns that adaptation financing is falling sharply even as climate shocks intensify. Another recent global analysis shows that climate misinformation is turning a crisis into a catastrophe by eroding public trust and delaying policy action.
Yet the GEO-7 report carries a crucial message, arguing that solutions also exist. Asked what has to be done to ensure the transformation in how societies produce and consume energy, food and materials as recommended by the report, he said: “The way we’re producing our food today, the way we’re producing and using our energy is leading to environmental degradation. If we want to limit climate change and biodiversity loss, we have to deal with the underlying causes.”
As the GEO-7 states, there may be a need to rethink the economic and financial systems that incentivize environmental destruction.
“We have to look at our governance structures around the world. And we also have to look at our economic and finance systems.”
When asked whether governments are heeding the science, Watson gave a cautious but honest answer:
“I think some countries are definitely acting on it. Other countries are not acting on it. So, it’s highly variable.”
The private sector reflects the same uneven pattern, he argued.
“Some of the private sector companies are really becoming more sustainable. Some are acting quickly. Some are acting slower.”
This inconsistency, combined with global polarization, has allowed misinformation and denial to flourish — and even shape national policies.
Many have increasingly expressed skepticism about politics’ ability to meet the moment when it comes to the mounting scientific evidence about the growing planetary emergencies. Mongabay asked Watson how to get politics to meet the science. “They have to start to believe it’s in everybody’s best interest to act.”
Most environmental treaties involve environment ministers who often lack large budgets and do not significantly influence finance or economic ministers, who, in most countries, have the power to decide on national budget allocations. For him, communicating with environment ministers alone is not enough. “We need to talk directly to agriculture ministers, energy ministers, finance ministers. And we must talk to the private sector. We mustn’t just focus on environment ministers.”
In other words: Science must be heard in the rooms where the real power lies.
Despite the grim data, GEO-7 identifies transformations already underway. Watson highlighted several: “It will be cost-effective to change our energy system. It will be cost-effective, socially acceptable and environmentally sustainable to change our food system.”
The report lays out practical pathways in energy, food, materials and finance. But Watson stressed that governments must invest now if they want to reap long-term benefits: “You do have to invest now in order to realize these benefits in the long term. This is not a freebie today.”
Banner image: Sir Robert Watson, one of the world’s leading environmental scientists and co-chair of GEO-7, attends the report’s launch at the UN Environment Assembly in Nairobi. Image by Photographer/UNEP.
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