The facts of climate change are stark. The global average temperature has risen around 2°F since 1900. Why do we care? Even small changes in the average temperature of the planet can cause dangerous shifts in climate and weather.  The scientists of the Intergovernmental Panel on Climate Change warned in their 2022 report that without a drastic reduction in greenhouse gas emissions, the world will continue to experience catastrophic consequences ranging from hotter heat waves and longer droughts to wetter storms. These weather extremes have exposed millions of people to severe food and water insecurity, especially in the global South.

Thankfully, climate tech investors are responding in force. Last year saw the creation of 64 new climate funds worth a combined $37 billion; in the first half of 2021 alone, investors closed as many climate-focused funds as they had during the previous five years combined. They aren’t being stingy about spending that cash, either—more than $23 billion flowed into climate startups in the second half of 2021, double the amount in 2020, according to data from Climate Tech VC.

The enthusiasm may remind some of the clean-tech bust a decade ago when investors plowed $25 billion into startups over the course of five years—and then lost more than half of that. One critical mistake those investors made was to approach companies attempting physical innovations based on science and engineering the same way they did companies developing software. That’s an error we don’t have time to repeat—especially not with both Congress and the Supreme Court blocking meaningful policy responses to climate change. For this set of technologies to make a dent in global warming, we need both more capital and more ways to deploy it.