This is today's edition of The Download, our weekday newsletter that provides a daily dose of what's going on in the world of technology.

Why worms (and microbes) are catching on as a manure pollution solution

Anthony Agueda, a third-generation California dairy farmer, pulls a rake through a bed of dark, wet wood chips to reveal a half-dozen squirming red earthworms. There are likely hundreds of thousands more wriggling just under the surface.

The worms and microbes are part of a "vermifiltration" system that cleans manure wastewater. The approach may dramatically cut methane, nitrous oxide, and water pollution.

Vermifiltration is just one of a variety of methods that farmers, companies, and scientists are employing to drive down manure pollution as the livestock industry faces growing pressure to address the environmental harms from one of the smelliest parts of the business.

Explore how the humble earthworm could reshape the future of sustainable farming.

—James Temple

MIT Technology Review Narrated: geoengineering gets a reality check

Solar geoengineering, the controversial idea that we could deliberately intervene in the climate system to counteract global warming, is moving beyond computer simulations and into the practical engineering challenges required to make it real.

Researchers are now working on aircraft, materials, and other systems for solar geoengineering. But as they delve into these details, they’re finding that even early deployment would require significant new infrastructure, time, and investment.

—James Temple

This is our latest