The political career of John Kerry, 82, has left a vast legacy that the Donald Trump administration is poised to squander. Among other things, Kerry was the key negotiator of the nuclear deal with Iran and the Paris Agreement. The former secretary of state and 2004 Democratic presidential candidate remains fully engaged in the energy transition through the global investment platform Galvanize. Kerry recently visited Barcelona to give a talk at Impact/Week, a conference for entrepreneurs, investors, and global leaders organized by Norrsken Barcelona, one of Europe’s largest startup hubs.

Question. Some of the biggest shifts on the global chessboard are being driven by energy: Trump’s diesel agreement with Russia and the tensions surrounding Iran. Is this proof that the energy transition is fundamentally a geopolitical issue, not just an environmental one?

Answer. Yes. It’s obvious that there are leaders in a number of countries who have said publicly that they’re not going to be dependent on the Strait of Hormuz for energy security, and there’s no economy that’s going to live in that kind of uncertainty. National security and international security challenges are now much more on the table. It is front and center.

Q. But many governments emerging across Europe today are not especially enthusiastic about the transition to renewables, and Trump is clearly not on board. Are we witnessing a backlash?

A. There is certainly a political backlash, and we shouldn’t minimize it. Decisions by governments matter. They can delay investment, create uncertainty, and make it harder to build the infrastructure we need. But I would distinguish the political debate from the reasons countries and businesses are pursuing this transition. They need affordable electricity. They want secure energy supplies. They want to compete for the industries and jobs of the future. Those interests don’t disappear when an administration changes. We also have to listen to what people are telling us. If people believe the transition means higher bills or that their community will bear the costs while somebody else gets the benefits, we have to address that. So yes, progress can be slowed, and gains can be reversed. Nothing about this is inevitable.

Q. Do you think then that the global climate agenda can survive a new era of economic nationalism?

A. It can. Economic nationalism is creating obstacles, but new technologies are making the economic case for the transition stronger. Better batteries, better turbines, and better solar panels can help overcome some of those barriers. Ultimately, business leaders have to look at their bottom line: What are their costs? What does this mean for their shareholders? What can they save by transitioning?

Q. Spain already generates more than half of its electricity from renewable sources. However, after the major blackout in April 2025, the debate over grid stability resurfaced. Do you believe that a renewables-dominated power system can operate safely without nuclear energy?

A. People are right to demand reliable electricity, but we have to be precise about what happened. The European investigation found a combination of failures involving voltage control, the way generating plants responded, and a cascade of disconnections. That is a much more specific diagnosis than saying Spain had too much renewable energy or was waiting for storage technology to be invented. The investigators also made clear that the solutions they recommend are technologically available today. Storage technology exists. Batteries are already being deployed at scale, and pumped hydropower has been operating for decades. We should keep improving those technologies, particularly for storing energy over longer periods. But storage is one part of the answer. You also need stronger transmission, connections between regions, flexible sources of power, and equipment and operating rules that keep the grid stable.

Q. What role do you see for artificial intelligence in the green transition?

A. I see enormous potential. AI can help us forecast electricity demand, operate grids more efficiently, develop new materials, and reduce the energy wasted in buildings and industry. Those are practical applications that can lower costs and accelerate progress. But we also have to account for the electricity, water, and infrastructure that AI requires. The benefits aren’t automatic. We need to measure what it actually delivers and make sure communities benefit from the investment. The growth in electricity demand creates an opportunity to modernize our infrastructure. We should use it to bring more clean power onto the grid, expand storage, and build a system that serves everyone more reliably. Ultimately, the test is whether we’re using this extraordinary capability to solve consequential problems. Can we make energy more affordable? Can we manufacture with less waste? Can we help communities prepare for extreme weather? That’s where I would focus our ambition.

Q. You have said we should move together in a multilateral system to achieve our goals, with the involvement of China. Do you think that is possible with the Trump administration?

A. No, but we have to. It’s worth talking about it, because you need to persuade people to make that happen. If people don’t engage in politics, you’re going to leave it to people who will screw it up. We’ve seen that.

Q. Do you expect any change after the midterm elections?

A. I do. If the House of Representatives becomes Democratic and the Senate does, you’re going to have a huge change.

Q. What is at stake in the midterm elections?

A. There’s a huge amount at stake: whether or not we’re going to be a country that adheres to law, enforces the law, respects the law. And whether or not we are going to act in a way that sends a good example for democracy. A lot of people are arguing against democracy, and democracy is going to have to prove its value and its capacity to deliver.

Q. Regarding the recent deal with Russia, do you think that Trump has put the short-term interests of his administration and himself ahead of the long-term interests of the U.S. and the security of its allies in Europe?

A. I wouldn’t frame it specifically that way. I think his decision to allow purchases of Russian oil despite sanctions is counterproductive and dangerous. It doesn’t honor the sacrifice of Ukrainians, and it undermines both what we ask of other countries and our support for Ukraine.

Q. You were one of the architects of the Iran nuclear deal. Looking at the current situation, do you believe there is still a diplomatic path forward, or has the conflict entered a dynamic that will be very difficult to reverse?

A. Let me be very clear: there is only a diplomatic way out. There is no possibility to resolve the question of Iran by war, and I think President Trump has already proven the inability of his strategy to be able to get what he wanted.

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