John Kerry, 81, has been practically everything in American politics. Born in Aurora, Colorado, he served as a U.S. senator for Massachusetts from 1985 until 2013. He was the Democratic Party’s presidential candidate in 2004, when he lost to George W. Bush. Barack Obama appointed him as secretary of state in his second term (2013-2017), where he played a decisive role in the signing of the Paris Agreement in 2015.
Those were very different times from Donald Trump’s turbulent second term. The incumbent president frequently launches attacks on science and is attempting to torpedo global efforts to contain global warming or alleviate the global environmental crisis.
Throughout this video interview — which Kerry granted to Le Figaro, la Repubblica, and EL PAÍS on the eve of the 2025 UN Ocean Conference, which was held in Nice, France — the subject of Trump was ever-present. The former secretary of state, whose last political appointment was as Joe Biden’s special presidential envoy for climate (2021-2024), now works for an investment fund focused on the energy transition.
Question. Why is the High Seas Treaty important? And is it a failure that, two years after it was drafted, several countries haven’t ratified it?
Answer. It’s a global failure that, after all these years, we still have no laws governing a large proportion of our oceans. The high seas [are] outside the jurisdiction of any country. And, as a result, there’s extraordinarily outrageous behavior on the high seas. We have countries engaging in modern slavery on ships. Also, in some areas, there are tens of thousands of small vessels engaged in illegal fishing. But they don’t do it alone; they [obviously] have to rely on larger vessels, whose flag isn’t always [legitimate]. These large vessels sit and wait for illegal vessels to bring them the fish, which they then process and ship around the world. There’s a lot of piracy. [The oceans offer spaces for] arms smuggling, drug smuggling, human smuggling… and we have no laws that have regulated these types of activities [or that] have been enforced. We cannot allow these activities to persist in the zone of darkness that exists on the high seas.
Q. This year, 2025, marks 10 years since the signing of the Paris Agreement. Trump has again withdrawn the U.S. from the pact. And, last year, global warming was already 1.5°C above pre-industrial levels. Do you think Paris will fail like the 1997 Kyoto Protocol?
A. Well, Kyoto had requirements that aren’t in the Paris Agreement, which allows each country to [craft] its own approach to this challenge. So, it’s really not the same. Trump withdrew from the Paris Agreement in his first term, but the American people remained. At the subnational level — states and cities, [through] their political leaders — continued to implement laws on renewables and the transition to a clean energy economy. More than 1,000 mayors, those in every major U.S. city, remained in the agreement. Additionally, 37 governors operate under what are called “renewable portfolio standards,” which require them to [generate a certain amount of their energy from renewable sources].
The [green energy] market is proving profitable and is attracting private capital in much greater quantities than ever before. Last year, around $2 trillion were invested in clean energy worldwide. On the citizen side, there’s the transition to electric vehicles, the installation of solar panels... there’s a whole host of things that are happening and will continue. But what President Trump has done has affected the pace of this transition. And the pace is critical, because science tells us that certain negative impacts will occur if we don’t act quickly enough to change course.
Q. What would you say to those who think the U.S. is not a reliable partner in climate and environmental diplomacy?
A. I would tell them that much of the United States continues to move in the right direction. Unfortunately, President Trump has obviously made engagement [with the U.S.] very difficult. And that’s a loss, not only for other countries, but for the United States, for our own citizens, who will not benefit from being a good partner. It’s very unfortunate. And those of us who have worked our entire lives moving in the right direction and promoting good policy — not ideological policy, but good policy, based on science — to respond to the challenge of the crisis we face globally are obviously disappointed. But we will continue doing everything in our power [to combat climate change].
Q. Are you concerned about how several large corporations and financial institutions in your country have recently shifted positions when it comes to the fight against climate change?
A. Some companies have publicly backed away from their commitments, but they say they’re going to continue putting the money and effort into achieving those goals. So, it’s too early to say what the level of impact will be. But I think it’s unfortunate that some people have felt compelled to do that. Obviously, they’re worried about the impact of retaliation against their businesses… but I think this will also contribute to slowing things down. The Wall Street Journal ran this headline a few weeks ago: “The Clean Energy Revolution Is Unstoppable.” When The Wall Street Journal runs that kind of headline...
What’s happening will affect the pace of the transition. But the energy transition will continue. And the biggest challenge is whether we commit to making it happen as quickly as the science says it needs to.
John Kerry, then-U.S. secretary of state, signs the Paris Agreement with his granddaughter at a ceremony held at the headquarters of the United Nations, in April of 2016.Mark Lennihan (AP)Q. In your country, scientists have been laid off and international databases are set to be shuttered. Do you think the government has entered into a kind of obscurantism or McCarthyism regarding science?
A. Indeed, some science projects and grants to universities have been cut. It’s a tragedy. We’ve learned over the centuries that science is essential for everyone. In 1755, Lisbon experienced a massive earthquake and, later, a tsunami. All the city’s churches were destroyed and around 40,000 people died. For years, this sparked a great debate among such notable thinkers as Immanuel Kant, François Voltaire and Jean-Jacques Rousseau. And the question was: why did it happen? Some argued that a vengeful God had unleashed his wrath on people for the way they were living. But that debate ultimately led to the Age of Reason, the Age of Enlightenment, based on science.
In a way, we left flat-earthism behind. [But] we’re now living in a new era of flat-earthism, where we have people trying to sell the idea that climate change is a hoax with no basis whatsoever. They’re spending billions of dollars talking about [so-called “clean coal”] and the virtues of oil and gas.
Q. But do you think this is a form of McCarthyism?
A. That depends on what you mean by McCarthyism. Is there a disregard for reality and facts? Is there a call to accuse people, to pit people against each other? Yes, there’s polarization. And polarization is really dangerous. But I think the important thing is that, centuries ago, we had a fight over facts and science. And now, we have a new fight in which we must restore credit to science.
We’re in a difficult situation, fighting against red herrings, against straw men... I had a colleague in the United States Senate named Daniel Patrick Moynihan. He was a great senator from New York and he said that everyone has a right to their own opinion, but not their own facts.
Q. And how can the world recover from these damaging U.S. actions toward research?
A. We will recover if people understand their own empowerment. France, Germany, [Europe overall] and more countries have the capacity to conduct science and increase investment. And that’s going to have to happen. It’s not unlike the debate over European defense needs in the context of Ukraine; [the EU has] decided to spend more.
Q. David Attenborough’s new documentary shows the importance of protecting marine reserves from bottom trawling. What do you think about this subject?
A. I think it’s absolutely essential that we protect these areas from bottom trawling. I was the chairman of the fishing subcommittee in the U.S. Senate. We rewrote our fisheries laws several times. And, in the process, we had many discussions about bottom trawling. We never found consensus. But [the practice is] extremely destructive, because it ravages the ocean floor indiscriminately. It uproots seagrass beds, which releases carbon dioxide that’s been stored in the ocean. It has a profound impact. I’ve seen [Attenborough’s] film and it really shows that destructive aspect. That’s not the right way to fish… we have better ways of doing it.
Q. Trump has approved an executive order authorizing deep-sea mining, including in international waters. What do you think about this?
A. That’s not really necessary and it also has the potential to cause extraordinary damage. We all know what mining has done to the Earth’s surface. I think it would be a very dangerous step.
Q. The 2025 UN Ocean Conference took place in the context of a fierce conflict between the Trump administration and the EU over tariffs. How might a trade war impact ocean protection and, more broadly, climate change?
A. I oppose tariffs. I believe they’re not the way to pursue thoughtful multilateral initiatives. [They create] unilateralism, which automatically becomes a kind of tit-for-tat that spirals out of control and has a profound negative impact on the certainty and clarity that the market needs. Large amounts of capital are already being withheld: many economists have predicted the possibility that this tariff battle will produce a recession. And we have precedents, like the 1920s with [President] Herbert Hoover, when we saw what happened with this [kind of] tariff battle.
I think the rest of the world is going to react. In the United States, many business leaders I know are deeply concerned about the direction in which the administration has moved. And I hope we can return to a more orderly and structured process. Now, that’s not to say that global trade shouldn’t be reformed and that — in some cases — better rules, better enforcement and better accountability aren’t needed.
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