At the ClimateLaunchpad Japan National Finals in Tokyo in August 2026, one of the early discussions included nuclear energy and smaller reactor concepts, which naturally caught my attention because much of my interest in climate begins with energy. From there, though, the room moved quickly into very different territory: semiconductor design, flood protection in Morocco, abandoned homes in rural Japan and an app for finding more sustainable shops in Tokyo.
The teams were competing with one another for the judges’ attention and for the chance to move forward, but the problems they had chosen were so different that comparing the technologies directly sometimes felt artificial.
The semiconductor presentation was one example. The company said its designs could make chips more energy efficient without simply accepting the usual trade-offs in heat, size or performance. The presenter talked about electric vehicles and AI data centers, where the issue is not only how much electricity the chips consume but how much heat they create and how much additional energy is then needed to cool the system. He even referred back to the Pentium 4 era, when computers could run extremely hot, to make the point more tangible. If the gains are real, the effect is easy to picture: a data center can do the same work while drawing less power and spending less energy getting rid of waste heat.
The judges were not satisfied with the performance claim alone. They wanted to know where the intellectual property came from and why this team could do something that much larger semiconductor companies could not. The presenter said the technology had been developed in-house by experienced engineers. That made the commercial opportunity easier to understand, but it did not remove the need to prove that the technical advantage was real and defensible.
A later presentation came from a landscape architect with experience in both Japan and Morocco. His proposal was far more physical. He wanted to use Japanese-style flood barriers to protect buildings and facilities in Morocco, beginning with the simplest version of the idea: put the panels in place before the water arrives and keep it outside.
The images were memorable because there was very little abstraction to them. One building floods, another stays dry because a barrier is standing between the water and the entrance. The presenter talked about airports, ports, electricity facilities and hotels as possible early customers, places where a flood can mean damaged equipment, lost business and days or weeks of disruption.
One of the judges suggested bringing insurers into the model. That made the economics much easier to see. A warehouse owner may not feel any urgency to spend money on flood protection during a dry year, but an insurer sees what happens after the water gets inside. If a barrier can reduce the size of a claim and keep a facility operating, the insurer has a reason to encourage installation before the next flood.
A few presentations later, the discussion was back in Japan and focused on akiya, the millions of vacant homes scattered around the country. The team behind Akiya Homes wanted to match some of those properties with people working on renewable energy, agriculture, eco-tourism and other environmental projects.
The attraction of the idea was obvious. An empty house could be used again, a project could gain relatively inexpensive space, and a town that had been losing people might see new activity. One of the judges, however, pointed to what exists beyond the walls of the house. Many of these properties are empty because the surrounding area has already lost jobs and population. A young family considering a move does not only ask what the house costs. They also care about where their children will go to school, whether there is work nearby, how far they are from medical care and whether there is enough activity in the town to build a life there.
Putting solar panels on an empty house or turning it into a base for an environmental project might help that property. It does not automatically rebuild everything around it. The presenters hoped successful projects would attract more activity, while the judge argued that local government and other institutions would have to be involved if the goal was broader regional revival rather than a series of isolated projects.
Nearby Finds brought the scale down again, this time to an everyday decision in Tokyo. The team wanted to begin in places such as Shibuya, Shinjuku and Meguro and make it easier for consumers to compare businesses on environmental factors rather than relying only on location, reviews or a shop’s own sustainability claims. Their customer research suggested that sustainability often mattered most when price and reviews were already similar. The person making the decision is still standing in a real neighborhood with limited time and a budget, choosing between two actual shops.
I wrote more about those business questions separately in Testing Climate Innovation. Here, what stayed with me was the contrast between the problems appearing one after another. In the space of a morning, the conversation moved from how a chip handles electricity and heat, to whether water can be kept out of a warehouse, to why an empty house remains empty, to what makes someone choose one cafe over another.
By the time the moderator called the break, he was laughing as he tried to remember everything that had been covered. Nuclear, semiconductors, flooding, akiya and Nearby Finds had all appeared in the same session.
The competition was real. Governments do not have unlimited budgets, investors have to decide where to put capital, good engineers can only work on so many projects, and public attention is finite. Climate technologies compete for all of those things even when they are addressing different problems.
That is why the distinction between competition and substitution matters. A more efficient chip can reduce the electricity needed by a data center, but the data center still needs a reliable power supply. A flood barrier may keep a warehouse open, while reliable energy supply helps keep the facility operating in the first place. A new use for an akiya may help a rural community, but that community still depends on functioning transport, infrastructure, energy and public services if people are going to stay.
Nuclear belongs inside that connected picture. Reliable, low-carbon electricity can support factories, railways, data centers, homes and new investment, while improvements in efficiency can reduce how much energy those activities require. Energy supply also interacts with resilience and regional development rather than sitting apart from them. A factory deciding whether to invest in an area cares about the reliability of the power supply, but it also cares whether roads work, whether flooding can shut the site down and whether people actually want to live nearby.
Seen from that angle, the morning did not look like a contest to find the single climate technology that should win. It looked more like a series of people arriving at different pressure points in the same economy and trying to make one of them work better.
The moderator’s difficulty remembering the order of the pitches was almost appropriate. By then we had moved from reactors to chips, from chips to floodwater, from floodwater to empty houses, and from empty houses to a shopping decision in Tokyo. The subjects were scattered, but the common thread was visible once each problem became concrete enough to picture: someone had to keep the lights on, use less power, keep water out, make a town worth living in, or choose differently at the point of purchase. The challenge was never that every idea needed to do all of those things. It was that each one had to be useful where it actually touched the real world.