Climate Action 15: 2024's top global innovators powering green solutions

The climate crisis is having profound effects across the globe, from more intense heat waves and drought to catastrophic floods and wildfires.

Solving the crisis requires aggressive action across industries like energy, transportation, agriculture, and finance. These industries need new solutions to slash greenhouse-gas emissions and become more resilient to a warming world.

And entrepreneurs, policymakers, organizers, and academics are at the center, spearheading game-changing advancements and confronting these challenges head-on.

This spirit of innovation is at the heart of Business Insider's third annual Climate Action list.

This year's honorees are 15 global trailblazers who are deploying technologies like low-carbon battery recycling and electric buses; equipping workers with skills to build a cleaner economy; and mobilizing grassroots movements against fossil fuels.

We asked each honoree to tell us about their approach to building a sustainable future, as well as the actions our readers can take to help solve the climate crisis.

Editor's note: Business Insider's reporters and editors nominated leaders based on insights from past Climate Action honorees, expert sources, and reader submissions. The leaders are listed in alphabetical order.

Derya Baran, cofounder and chief engineer officer, Iyris

Saudi Arabia, with its hot desert climate and little fresh water, is one of the most difficult farming environments. The country relies on imports to supply most of its food but wants to grow more at home. Baran's research into solar materials led to an invention to extend farmers' growing season in greenhouses while using less water and electricity.

Baran developed an additive for plastic greenhouse covers that blocks heat but not sunlight. The product, called SecondSky, is part of a suite of technologies developed by Iyris, a startup Baran cofounded in 2021 to help farmers adapt to extreme heat and water scarcity.

Iyris' research has found that SecondSky can keep the greenhouse cool while reducing water and energy use by up to 30%. The reductions are particularly important in Saudi Arabia, where the majority of fresh water comes from desalination plants powered by fossil fuels.

Iyris, which has raised $16 million so far, said SecondSky is used by growers in 15 countries, including Saudi Arabia, the United Arab Emirates, Egypt, and Spain. Baran noted that farming in greenhouses is becoming more popular globally because the climate crisis is making extreme heat and weather more frequent.

"A lot of agriculture is done in open fields," said Baran, who's also an associate professor of material science and engineering at King Abdullah University of Science and Technology. "With climate change, there is demand for controlled environments."

Iyris in October also launched a sustainable-farming pilot in Saudi Arabia with chemical and plastic manufacturers as well as companies including Red Sea Global, a luxury tourism developer. The pilot is testing a model for regenerating unproductive farmland and includes a greenhouse using SecondSky technology made from plastic waste.

Inna Braverman, founder and CEO, Eco Wave Power

Braverman traces her desire to change the world to the Chernobyl nuclear disaster in 1986. She was two weeks old when a nuclear reactor at the power plant in northern Ukraine exploded, releasing radioactive material into the atmosphere. Braverman, who lived 200 miles away in Cherkassy, said she nearly died from exposure to the toxic plumes. But her mom, a nurse, resuscitated her before paramedics arrived to bring her to the hospital.

"I grew up always hearing this story," Braverman said. "I got a second chance at life, so I thought I should do something good with it."

Her family moved to a small town in Israel when Braverman was 4. Her first job out of college was as an English-Hebrew translator at a renewable-energy company. There she learned about the enormous potential of wave energy, which is created as wind blows across the ocean. A UN climate panel estimated that harnessing wave energy could supply 20% more electricity than the world produced in 2022.

"I didn't have money, I didn't have contacts, and I didn't have the technical background," Braverman said, adding, "But I decided I'm the person for wave-energy commercialization."

The first wave-energy patent was filed two centuries ago. Braverman started researching why wave energy wasn't already being used as a power source. She identified a handful of problems. Projects were tested far off the coast and attached to the seabed, where harsh ocean conditions degraded the equipment. The projects were expensive to connect to power grids on land. The risks scared off insurers.

Braverman cofounded Eco Wave Power in 2011 with David Leb, a serial entrepreneur who invested an initial $1 million. They hired five engineers in Ukraine to design new technology. Today it uses metal "floaters" that attach to shoreline infrastructure like piers and breakwater jetties. As floaters move with the waves, they compress hydraulic fluid that then powers a generator on land, creating electricity that can be transferred to the grid. The higher the wave, the higher the pressure. If the waves get too high during a storm, floaters can fold up to avoid damage, Braverman said.

Eco Wave Power operated its first pilot project in Gibraltar from 2016 to 2022. A second pilot, in Israel, started sending electricity to the power grid in August 2023. It's developing a third pilot, in the Port of Los Angeles, with Shell. Braverman said the first commercial plant is expected to be built in Porto, Portugal, in the coming years and generate enough power for about 20,000 households.

Charles Callaway, director of workforce development, We Act for Environmental Justice

For Callaway, environmental justice is rooted in the community.

As the director of workforce development at We Act for Environmental Justice and a resident of West Harlem for over 15 years, Callaway has organized with people in New York City to push for community-driven and sustainable urban planning.

People of color and low-income populations often bear the brunt of environmental pollution — they're more likely, for example, to be exposed to toxic waste sites, landfills, and chemical plants. We Act focuses on informing marginalized residents about environmental issues affecting their health and pushing for stronger climate protections.

The organization lets city officials know what residents are experiencing in their neighborhoods "because environmental justice is all about understanding what the people need on the ground," Callaway said.

In 2008, Callaway worked alongside a community task force and the Metropolitan Transportation Authority to rebuild the Mother Clara Hale Bus Depot as Harlem's first green bus depot. The garage was outfitted with features like a green roof and an air-exchange system that could filter exhaust fumes released from diesel buses and bring in clean air from outside the depot. Callaway said the system provides cleaner air for both bus-station workers and communities living in the area.

Callaway is now expanding his work in the solar industry. In 2019, he helped create Solar Uptown Now Services, a solar-installation worker cooperative, after noticing that graduates of We Act's Green Institute program had the training and skills to work in the green-energy field but couldn't find jobs. Callaway said that in the past five years the co-op helped install 20 megawatts' worth of solar panels in the city.

Callaway also educates building owners and residents about the economic and environmental benefits of switching to solar. He said his role in the green-energy movement is to "ensure that solar is something that people of low income actually benefit from."

Gretchen Cara Daily, cofounder and faculty director, the Natural Capital Project at Stanford University

Daily said the Natural Capital Project was partly inspired by Costa Rica. The country had one of the highest rates of deforestation in the world in the 1980s — but starting in 1996 it outlawed chopping down forests and started paying landowners to plant trees, protect watersheds, and practice sustainable forestry and agriculture.

"Leaders in Costa Rica were trying to turn around the fatal flaw of our economic systems, which is that they're totally blind to the value of nature," Daily said. "Forests are only valued when cut. How do we turn that equation around?"

Daily cofounded NatCap at Stanford in 2005. The project maps and measures where investments in nature can deliver the highest returns for people and biodiversity, and then helps governments, financial institutions, and other companies craft plans to carry them out. NatCap developed a suite of software tools, known as InVEST, that model scenarios based on research by more than 1,000 scientists around the globe. It is now used in more than 185 countries.

Daily said nature has many economic and social benefits that people often overlook. Wetlands or coral reefs along coastlines can protect people from rising sea levels and severe storms. Forests can store water for hydropower and keep it clean for people to drink. Green spaces help keep cities cool during extreme heat. Mountains and marine life attract tourists.

NatCap has worked directly in more than 70 countries, Daily said, including Belize and China. NatCap supports China's efforts to conserve 51% of its land, which involves paying 200 million people to steward land in ways that mitigate flooding, secure water supplies, and renew agricultural soils so they produce more crops and absorb more carbon. NatCap helped Belize devise a plan to restore coral reefs and mangroves, which in turn created a natural barrier to the effects of storms while boosting revenue from tourism and fisheries. The plans in China and Belize involved government agencies, NGOs, multilateral development banks, and private industry.

Daily said NatCap accelerated its approach, working in 16 countries in 16 months last year, under a Global Environment Facility-funded program with three international development banks. NatCap is also setting up a technical-assistance center at Stanford to create a much larger pipeline of experts who can help countries and industries like banking and agriculture integrate nature into their policy and finance decisions.

Juan Carlos Navarro, minister of environment, Panama

Navarro, who took office in July alongside Panama's newly elected president, José Raúl Mulino, has brought global attention to the environmental degradation of the Darién Gap. Over the past few years, the 60-mile stretch of rugged tropical jungle that connects Panama and Colombia has become a major route for migrants coming to the US. Last year, more than 500,000 people — many fleeing economic collapse, violence, and poverty in countries like Venezuela and Haiti — made the journey.

"The human and environmental impact is absolutely horrific," Navarro said, describing deforestation and waterways filled with trash and gas leaked from boats carrying migrants.

The pollution has made rivers unusable for drinking and fishing. There are no roads, so makeshift routes cut through the Darién Gap, a UNESCO World Heritage site. Navarro said he had talked to migrants who described being raped and robbed at gunpoint and witnessing murders at the hands of Clan del Golfo, a drug cartel also involved in human trafficking.

Panama can't fix it alone, Navarro said, which is why he has requested that $3 million of a $10 million US aid package approved for Panama be set aside for environmental cleanups and to support local Indigenous communities that have been affected. He's waiting for a response from the US State Department.

About four decades ago, Navarro traversed the Darién Gap. He remembers pristine rivers, forests, and few people, except for the Indigenous communities who've lived there for thousands of years.

Navarro said that cleaning up the Darién Gap is part of a broader plan to ensure that Panama's economic growth is sustainable. The Mulino administration is prioritizing investments in national parks to attract more ecotourism, he said. While Panama's forests already absorb more carbon than the country emits — making it one of the few "carbon-negative" countries — the government is supporting renewable energy like solar. Another priority is improving waste infrastructure in Panama's cities.

Navarro had a decadeslong career in public service and environmental advocacy before becoming Panama's environment minister. He cofounded a solar company, NSolar, in 2015; was twice elected mayor of Panama City; and founded Panama's environmental NGO, the National Association for the Conservation of Nature, in 1985.

Reinhold Gallmetzer, founder, Center for Climate Crime Analysis

Large swaths of the Amazon rainforest are deforested illegally each year, even though countries and companies have laws and policies against those actions. Gallmetzer said part of the problem is that law enforcement and companies don't have the tools to collect enough evidence of illegal deforestation.

Gallmetzer founded the Center for Climate Crime Analysis in 2018. The center investigates illegal deforestation in Brazil, Peru, and Colombia through techniques including analyzing satellite imagery; scouring publicly available data from governments, companies, and scientists; and partnering with people and NGOs on the ground. It mainly targets the cattle, palm oil, and timber industries — the leading drivers of deforestation in the Amazon — and then shares its findings with law enforcement, companies, NGOs, and investigative journalists to help hold culprits accountable.

The center and its partners have connected beef sold at international supermarkets and collagen used in health supplements to illegal deforestation in the Brazilian Amazon. It also found that two carbon-credit projects in the region that claimed to prevent deforestation and emissions may have been used to illegally launder timber. Another investigation found that a coal mine in Peru contaminated the environment with toxic metals and harmed the local population.

As a result of the center's investigations, the French supermarket chain Carrefour in 2022 stopped buying beef from two slaughterhouses owned by Brazil's JBS, the world's largest meat packer, that were linked to illegal deforestation. Vital Proteins, a major collagen-supplement maker that's owned by Nestlé, said last year that it would end sourcing from the Amazon region. In June, Brazilian authorities arrested five people accused of selling $34 million worth of carbon credits and issuing fake documents as part of a scheme to launder timber from illegally deforested lands. Norway's largest sovereign wealth fund in 2019 divested itself of Glencore, a global mining giant that had a majority stake in the Peruvian coal mine accused of contamination.

Gallmetzer said the center was expanding its investigations into methane emissions from oil and gas infrastructure and waste dumps now that satellite imagery and AI can rapidly detect and measure the source of emissions.

Diane Gilpin, founder and CEO, Smart Green Shipping

The global shipping industry abandoned wind sails in the late 1800s, slowly replacing them with engines fueled by coal and then oil. The industry is estimated to account for 3% of global greenhouse-gas emissions, and Gilpin is hoping that using sails again — albeit high-tech ones — will help solve the climate crisis.

In 2014, she founded Smart Green Shipping, which developed a 34-meter sail known as FastRig designed to automatically turn to the best angle for wind and speed. It can retract during still conditions and storms, or when navigating under bridges and through harbors. The company's software selects optimal routes based on global weather data and quantifies how much fuel a ship saves as a result of using the sail. FastRig could be retrofitted to the decks of about two-thirds of ships that transport fossil fuels, grain, wood, chemicals, and other goods — or about 40,000 vessels.

The combined carbon footprint of those vessels would drop by 30% annually if they were installed with FastRig, based on modeling by Smart Green Shipping and calculations by the International Windship Association. In October, a nuclear cargo ship with FastRig set sail from Barrow-in-Furness, a port town in the UK. Gilpin said an enormous amount of data was collected on the trip and should demonstrate to the shipping industry that FastRig can be part of a low-carbon future. The results are expected by early 2025.

The industry is under pressure to slash its emissions. The UN's International Maritime Organization, a global regulator, is drafting a carbon tax that would require shipping companies to pay a fee for polluting. The European Union also requires industries — including large ships — to pay for their emissions. Still, progress is slow, Gilpin said. She added that there's a codependency between shipping and fossil fuels, because 40% of global cargo is oil, gas, and coal.

"There's not much incentive to change," Gilpin said. "We say, 'You won't need to use as much fuel.' But the oil industry is incredibly powerful."

Gilpin said that once the first sea trial wraps up, Smart Green Shipping aims to equip a larger vessel with six FastRigs. The goal is to retrofit 70 ships by 2029. The company has backers including a Japanese shipper called MOL Drybulk — one of the largest shipping companies in the world — the UK renewable-energy firm Drax, and the UK government.

Gilpin said she welcomes competition because Smart Green Shipping alone can't retrofit all 40,000 ships. "We need other players," she said.

Roberta Tuurraq Glenn-Borade, Iñupiaq, project coordinator and community liaison, the Alaska Arctic Observatory and Knowledge Hub

Glenn-Borade's work documenting the environmental observations of coastal Arctic Alaska communities is rooted in her belief in the strength and depth of Indigenous knowledge.

She serves as the project coordinator and community liaison for the Alaska Arctic Observatory and Knowledge Hub, or AAOKH, a monitoring network of Iñupiat observers who routinely track environmental changes in the Arctic's land and sea, including the weather, sea-ice levels, and tundra and river systems. Participants share their insights through online databases and maps.

Glenn-Borade says AAOKH's work is also shared with federal agencies such as the National Weather Service. AAOKH is in the early stages of partnering with the organization to help improve forecasts for sea ice through local observations, including gathering information about what specific ocean, weather, and sea ice conditions should be considered. Glenn-Borade facilitates what she calls "knowledge exchange meetings" between federal agencies and Indigenous community members.

Glenn-Borade has worked with AAOKH since she was a master's student at the University of Alaska Fairbanks, where she produced a story map with photos, audio clips, and data gathered from local observers. Her hometown, Utqiaġvik, Alaska, is one of five Arctic communities participating in the monitoring network.

She describes Utqiaġvik as a whaling community with strong ties to its culture and traditions — as well as a frequent site for Arctic research. But growing up, she often noticed a cultural gap between the scientists who came to conduct their research in Arctic communities and the people who lived there.

As AAOKH's community liaison, Glenn-Borade aims to bridge this divide and elevate the expertise of Alaska Native communities affected by the climate crisis. "We can only understand how best to respond if we know exactly what's going on in each community from their voices, from their perspectives," she said.

Glenn-Borade also hopes for more "acknowledgment and recognition of Indigenous knowledge as meritable science," especially in a world where Native communities often have to justify the value of their oral histories and ecological knowledge through data to gain access to funding and resources.

"We're working to elevate the potential for Indigenous knowledge and observations to not just inform climate adaptation and responses but to lead some of that," she said.

Cynthia Houniuhi, president, Pacific Islands Students Fighting Climate Change

A trip to Fanalei, a village in the Solomon Islands, helped ignite Houniuhi's climate-justice journey.

Many of Houniuhi's family members lived in Fanalei. When she returned to visit the island as an elementary-school student, she saw that the sea levels had risen considerably. Many of the houses that were once elevated by stilts on the shore were now standing directly on the water, and some residents were forced to relocate.

Houniuhi said these rapid environmental changes also affected the island's daily subsistence activities like fishing. "When you have those daily conversations, when it's been affected, you feel it's not abstract," she said.

At the University of the South Pacific, she enrolled in a course on international environmental law. Taking classes with other students experiencing the effects of the climate crisis on their homelands, Houniuhi wondered how they could use their degrees to make a difference.

In 2019, Houniuhi was one of 27 students from her law school to form Pacific Islands Students Fighting Climate Change, an organization led by young people from the Solomon Islands, Fiji, Vanuatu, and Tonga. She now serves as its president.

The organization's main goal is campaigning to seek an advisory opinion from the world's highest court, the International Court of Justice, on states' obligations regarding the climate crisis and human rights. An advisory opinion provides legal advice to the United Nations or other specialized agencies.

Houniuhi said the campaign's ambition to take on the highest level of the law reflects the severity of the problem and the group's urgency to take action. "We may be small in size and often in documents referred to as 'Small Island Developing States,' but we are thinking big," she said. "Some of the biggest initiatives are born in the small island states."

Houniuhi told Business Insider that the advisory opinion could help provide baselines for state action on one of the most pressing issues of this century.

"We need the global world to be of the same mind," Houniuhi said. "That's the only way forward, and we believe that everyone is equal under the law and has a right to access justice."

Arvind Kumar, vice president of global research, Prasad Seeds

Rice is a staple for more than 3 billion people, and demand is on the rise as populations increase across Asia and sub-Saharan Africa. Scientists predict the climate crisis could shrink rice production globally as frequent droughts harm seedlings or extreme rainfall floods crops at the wrong time. The threats risk food security and farmers' livelihoods.

Kumar has spent decades developing rice varieties that can withstand those extremes in countries including India, the Philippines, Nepal, Bangladesh, and some in Africa. As vice president of global research at Prasad Seeds in Hyderabad, India, Kumar is working on direct-seeded rice varieties that use less water and can be harvested with a machine, which would reduce labor.

"Due to climate change, we will not have enough water to cultivate rice the same way that we are doing now," Kumar said, noting that traditional farming involves growing seedlings in a nursery and then transplanting them in flooded fields. "Labor is going to become more costly, which agriculture can't sustain, especially in poor countries."

Before joining Prasad Seeds, Kumar spent nearly 15 years at the International Rice Research Institute in the Philippines. There, he spearheaded an initiative that identified traits in rice plants that increase production under drought conditions. Now more than 70 drought-tolerant rice varieties are grown in 10 countries across South and Southeastern Asia, across Africa, and in the village where Kumar grew up in India. He said the varieties can boost rice yields by about 20%. Kumar has also trained more than 30 researchers who are now advancing the field of climate-resilient agriculture.

Kumar was raised on a rice farm in the village of Subhanpur in northeastern India. The region's rice production historically relied on monsoon rains. He said that rising global temperatures were making that rainfall more erratic, threatening farmers' harvests.

Ari Matusiak, cofounder, president, and CEO, Rewiring America

Climate anxiety is on the rise, in part because people feel like the crisis is out of their control. In cofounding Rewiring America in 2020, Matusiak sought to show people the many actions they can take at home to help reduce a big source of greenhouse-gas emissions.

Whether the cars we drive and the appliances we use to heat and cool our homes and cook our food are powered by renewable energy or fossil fuels are among our highest-impact climate decisions. An analysis of federal data by Rewiring America found that 42% of US energy-related emissions came from homes and cars. Matusiak aimed to make the switch to greener living easier and more affordable.

That vision has since been brought to life. Several initiatives in the Inflation Reduction Act aimed at reducing the costs of electrifying homes and making them more energy efficient were informed by policy papers coauthored by Matusiak. That includes a nearly $9 billion home-energy rebate program. Some states started doling out that money this year to homeowners and landlords who install appliances like electric heat pumps and stoves, among other upgrades. Rewiring America created online tools to help Americans craft their own electrification plan and calculate savings from new rebates and tax credits. The group said more than 1 million people had used the savings calculator.

Matusiak also advocated for the law's Greenhouse Gas Reduction Fund, a $27 billion grant program designed to fund community climate projects with private capital. A coalition that Matusiak helped assemble — and now co-chairs — called Power Forward Communities received $2 billion to electrify single-family and multifamily housing across 156 communities in 46 states that pledged to participate.

Matusiak said that while there's an enormous amount of work ahead, he's optimistic. His job is to help people understand the value of going electric, such as saving money on their utility bills, living in healthier homes with better air quality, and protecting the planet.

Duncan McIntyre, founder and CEO, Highland Electric Fleets

Many school districts want to switch to electric buses to improve local air quality but are held back by tight budgets and the daunting infrastructure project of replacing the technology.

Highland Electric Fleets is trying to make the switch easier. The company strikes 10-to-15-year contracts with schools and then goes out and procures buses and charging equipment, electrifies bus depots, manages charging, trains drivers and mechanics, and applies for state and federal tax breaks to bring down the project's costs. Schools pay a monthly bill for the services.

Since founding Highland in 2018, McIntyre has raised $250 million from investors and helped more than 100 school districts across the US start using 1,100 electric buses. Beverly Public Schools in Massachusetts — a neighboring town to where McIntyre lives — was the first customer. Some school districts have also installed vehicle-to-grid technology, which allows bus batteries to serve as backup power during outages or ease stress on the grid during times of high demand.

McIntyre spent his career in renewable energy. His first startup, Altenex, was the first marketplace for Fortune 500 companies to buy wind and solar power for their own operations. McIntyre sold Altenex to the utility Edison International in 2015 for an undisclosed sum and worked there for two years before taking time off to draft a business plan for Highland. McIntyre said that during that time he watched his young son board a school bus that pumped exhaust out of a tailpipe.

"I could see the benefit to kids," he said. "Their lungs are not as well developed, so the toxins in a diesel exhaust affect them more substantially than adults."

Roishetta Ozane, founder, director, and CEO, Vessel Project of Louisiana

In late January, Ozane was planning a sit-in protest at the US Department of Energy when she got the news: The Biden administration had paused approval of new terminals to export liquified natural gas, or LNG, until it could assess the effects on the climate crisis and energy costs for Americans.

It was a win for Ozane, her fellow environmental-justice activists, and scientists who are pressuring the White House to curb the use of fossil fuels that spew greenhouse-gas emissions and pollute local communities. That includes Sulphur, Louisiana, where Ozane lives with her six children. The region has many petrochemical and plastic plants, oil refineries, and LNG terminals. It's also the proposed site of the largest LNG terminal in the country, known as Calcasieu Pass 2.

Ozane's organizing and advocacy helped spark a movement against LNG, which had been seen as a "bridge" fuel in the transition to renewable energy because it burns cleaner than coal. But LNG is primarily composed of methane, a gas with 80 times the warming power of carbon dioxide over a 20-year period. Methane also leaks from oil and gas infrastructure, including wellheads, pumps, and pipelines. The process of making LNG so that it can be transported overseas creates even more emissions. Some research suggests LNG is worse than coal for the planet.

Ozane said she made the connections between industrial pollution, environmental racism, public health, and climate disasters several years ago. She founded the Vessel Project Louisiana, a mutual-aid and disaster-relief group, in 2020 after losing her home to back-to-back hurricanes, Laura and Delta. Her fight for clean air and water is also a fight for her children, two of whom have asthma, a disease that air pollution can worsen. Black and brown communities are also more likely to live in areas with heavy pollution, partly because of racist housing policies in the US that pushed them into undesirable areas. A judge in July blocked the Biden administration's LNG pause, but a spokesperson for the Department of Energy said it was updating the economic and environmental criteria it uses to approve new export terminals.

Ozane continues to protest new fossil-fuel projects. This summer she marched on Wall Street to pressure banks, private-equity firms, and insurance companies to stop backing coal, oil, and gas expansion.

Liz Ricketts, cofounder and executive director, The Or Foundation

Ricketts said her life changed after she spent a week in Accra, Ghana, in 2011 and toured Kantamanto Market, one of the largest secondhand textile markets. She was inspired by entrepreneurs recycling millions of garments. But as much as 40% of those garments are thought to go unsold and end up as waste.

Ricketts described the market as an example of the global fashion industry's excess and the human and environmental toll it takes on developing countries. Ricketts watched the rise of fast fashion as a designer and stylist in New York and London. Brands went from producing two clothing lines a year to churning out clothes monthly, and in some cases weekly, to keep up with social-media trends. Quality deteriorated, and waste piled up. McKinsey found that from 2000 to 2014, clothing production doubled and the number of garments purchased per capita increased by about 60%. Its analysis indicates that for every five garments made, the equivalent of three end up in a landfill or incinerated.

Ricketts didn't want to be a part of that new business model and so pursued more sustainable work. In 2011 she cofounded The Or Foundation, a nonprofit in Ghana that offers grants and job training to workers in Kantamanto Market, funds small projects to make the market a safer place to work, engages government officials to improve waste collection, and conducts environmental and socioeconomic research to inform policy locally and globally.

"The root of the issue is the business model of overproduction, which is volumes over value," Ricketts said. "There's no longer enough embedded value in a garment to cover the costs of the secondhand-clothing trade."

The foundation also advocates a policy known as extended producer responsibility, which requires global fashion companies to pay fees to fund the collection, sorting, and recirculation of their products. Ricketts argued that this should be global because so much secondhand clothing is exported from rich countries to poorer ones that often don't have the money to invest in modern waste systems. She also argued that brands that make the most clothing should pay higher fees in order to discourage overproduction.

Chao Yan, cofounder and CEO, Princeton NuEnergy

One of Yan's earliest childhood memories was wiping black soot off his school desk each morning. He grew up in Taiyuan, in China's Shanxi province, a hub for coal mining and steelmaking. The industries fueled the country's rapid economic development but also polluted the skies. Yan said he often wondered whether there was a cleaner way to produce energy.

This question led him to study chemistry, and he earned a doctorate from the New Jersey Institute of Technology before spending four years as a postdoc at Princeton University. He researched batteries and realized that even though they store and produce electricity without emissions, there remains a dirty part of the supply chain: recycling.

Conventional recycling involves soaking batteries in acid and then extracting and refining their valuable materials — an energy-intensive process that creates pollution. Yan and three other scientists cofounded Princeton NuEnergy in 2019 after developing a low-temperature, plasma-assisted separation process designed to purify and recover up to 98% of the materials in lithium-ion batteries. The process doesn't use acid and avoids the leaching and refining steps. The Energy Department's Argonne National Laboratory estimates that it costs 40% less and creates 70% fewer emissions than conventional battery recycling.

"When you get these valuable materials from a mine, it's also a dirty process," Yan said, referring to lithium, cobalt, nickel, and other critical minerals. "If you don't recycle them, it's a huge waste."

Building more battery recycling in the US is also a national security issue. China dominates the industry and the supply chains for metals needed for electric-vehicle batteries, solar panels, and other renewable-energy technologies. The US is trying to shore up its own mining and manufacturing base to curb China's power, including in battery recycling.

Princeton NuEnergy in June broke ground on its first commercial plant in South Carolina, with a goal to start production in the first half of 2025 and eventually recycle enough materials for 100,000 EV batteries annually. Yan said he was partnering with automakers, consumer electronic companies, scrapyards, and car dealerships to source end-of-life batteries.