She's the Treasury secretary. The point isn't about reducing green tech, it's reducing Chinese competitive advantage. She's calling for the us and eu to ramp up production. As policy, they are trying to buy time, by blocking Chinese access to Western markets in the meantime.
They believe China is massively subsiding this push with a specific intention to destabilize and blow out western markets. So by reducing Chinese access to Western markets, while also making Western markets more competitive, they believe they can improve their geopolitical position.
Believe that or don't, but as a federal Western policy maker, that's their take.
Indeed, the mile high view is that in the meantime, folks who want affordable greener tech will have less access to it, and that is a bummer