Today: In a fast-changing world, markets that were once considered incompatible are forging new links; the fading coal town that banked on a wind-power boom; how we're flushing a lot of energy down the drain.

Welcome back: Can a weapons manufacturer be considered sustainable?

On both sides of the Atlantic, companies, think tanks and governments are recalibrating arguments for investing in renewables, minerals and clean technologies. Whereas before, companies invested in these areas to decarbonise or to reduce the effects of climate change, now the reasons being given are for a strong supply of minerals to support weapons manufacture, critical infrastructure and conflict deterrence.

Europe has signaled moves to rearm and the stocks of European defense companies have soared, despite the effects of Trump’s trade war on global markets, WSJ Pro Sustainable Business's Yusuf Khan writes.

In a fast-changing geopolitical environment, amid tariffs and a pushback on green initiatives, sustainability and defense industries are forging new relationships with mutual ambitions.

• Startups That Set Out to Fix the Climate Now Talk About Jet Fighters

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Up and down the East Coast, communities staked their futures on wind farms, a key part of President Biden’s renewable-energy push. Government officials threw money into related investments onshore: manufacturing facilities to produce supplies; ports to assemble them; and training programs for a blue-collar workforce to install them.

The hope was to create the type of high-growth industry increasingly destined for the Sunbelt, the WSJ's David Uberti writes.

In Somerset, Mass., a planned factory on the site of an old coal plant would build underwater cables funneling energy onshore from skyscraper-size wind turbines off the coast. Biden even visited in 2022, casting the $200 million project as a symbol of America’s clean-energy revolution.

But these days the property stands empty, patrolled by deer and wild turkey—a sign of a dream deferred.

The election of President Trump hammered what many believe was the final nail in the coffin for the proposal, which already was facing shaky demand and permitting delays. The Italian company behind the project pulled out days before his inauguration.

According to Energy Department estimates, Americans flush the equivalent of 350 billion kilowatt-hours of energy from hot water down their drains annually. A substantial portion of this thermal energy is recoverable, yet most municipalities and building managers have barely begun to tap this resource, Jackie Snow writes for the WSJ.

Wastewater heat-recovery systems, which have been widely adopted in Europe, are gaining momentum in North America as the technology becomes more accessible and cost-effective. Major projects in Denver; Vancouver, British Columbia; New York state; and King County, Wash., are either expanding existing systems or breaking new ground.

The technology is relatively straightforward. The temperature of wastewater is typically between 54 and 67 degrees Fahrenheit, making it a source of thermal energy. Heat-pump systems can recover that energy and use it to warm buildings and heat water, and to cool buildings in warm weather. 

Vancouver was an early adopter of this approach in North America. The utility now delivers 70% of its energy to customers using renewable energy. That has reduced carbon emissions by around 7,000 tons a year compared with natural gas, according to Derek Pope, who oversees the system.

• LG, Samsung sue India over electronic-waste pricing. (Reuters)
   
• Apple cuts manufacturing emissions in half from 2020. (ESG Today)
   
• Trade war threatens one of America’s top energy exports. (WSJ)
   
• SEC approves first U.S. "green" stock exchange. (ESG Dive)
   
• Tariffs risk higher costs at U.S. nuclear plant, builder says. (Bloomberg)
   
• China dominates solar. Trump tariffs target China. For U.S. solar industry, that means higher costs. (AP)
   
• Climate philanthropies fear Trump blow from loss of tax-free status. (FT)
   
• Former Energy Secretary Granholm becomes energy strategist. (Trellis)

WSJ Pro Sustainable Business gives you an inside look at how companies are tackling sustainability. Send comments to bureau chief Perry Cleveland-Peck at perry.cleveland-peck@wsj.com and reporter Yusuf Khan at yusuf.khan@wsj.com. Follow us on LinkedIn at wsjperry and yusuf_khan.