2024年2月，《华尔街日报》披露，以色列初创公司 Stardust Solutions 正在开发可被喷入平流层的微粒，用于降温地球；5月14日公布的预印本显示，其主要粒子直径小于千分之一毫米，分为两类：一种是经特殊处理表面的无定形二氧化硅球体，另一种是外壳为无定形二氧化硅、核心为碳酸钙的同尺寸粒子。

这些粒子被包装为一个“端到端”的太阳地球工程方案，但芝加哥会议上的反应并不一致。与主流依赖硫酸盐气溶胶的路线相比，硫酸盐会造成健康风险并终将下沉，而无定形二氧化硅本身不直接构成健康担忧，但其在长期风化后是否真的比硫酸盐更安全，仍未获得广泛认可。

公司资金规模进一步放大了争议：最初通过 Awz Ventures 的投资为 1500 万美元，2025年10月又有第二轮 6000 万美元加入，使其轻易成为该领域资金最充足的研究机构。太阳地球工程长期存在争议，而 Stardust 的商业利益和相对较晚的透明化，使其既可能推动技术进展，也可能在短期内加剧争论。

In February 2024, the Wall Street Journal reported that Stardust Solutions, an Israeli startup, was developing tiny particles for lofting into the stratosphere to cool the Earth; preprints released on May 14 showed that its main particles are less than one-thousandth of a millimetre across, in two forms: specially treated amorphous-silica spheres and same-sized particles with an amorphous-silica shell and a calcium-carbonate core.

The particles are presented as part of an “end to end” solar-geoengineering system, but the reception at a Chicago meeting was mixed. Compared with the main sulphate-aerosol approach, which carries health risks as particles drift downward, amorphous silica is not itself a health concern, yet it remains unproven that Stardust’s particles will be safer after years of weathering.

Funding has sharpened the controversy: the original $15m investment through Awz Ventures was followed in October 2025 by a second round bringing in $60m, making Stardust easily the best-funded research outfit in the field. Solar geoengineering remains contentious, and Stardust’s commercial incentives and long silence mean its work may advance the science while also intensifying the debate in the short run.

Source: Could microscopic spheres of silica help cool the planet?

Subtitle: Private money is bringing new ideas—and new concerns—to solar-geoengineering research

Dateline: 5月 21, 2026 04:17 上午 | CHICAGO