With so many roads to pursue, it’s been vexing to see that a lot of the focus from tech companies has been around direct air-capture of carbon — a kind of Ghostbusters approach of sucking up the baddies. That’s all well and good, but it only ameliorates the problem with creative cleaning-up rather than by solving it at the source.

The clean energy opportunities are legion, especially as cities and states show more commitment to fighting climate change than the Trump administration. Localities are setting energy targets for many services they deliver, all of which will require vendors with creative solutions.

And as governments increase their support for electric vehicles, which could make up a significant part of passenger car sales in the next 20 years, there is a greater demand for innovation in batteries and storage, as well as in charging solutions that are faster and more efficient.

There is some positive movement in the private sector. One of the more interesting efforts is around what is called a “circular economy” — essentially recycling on steroids in which products are designed at the outset never to be thrown in a landfill. BlackRock, in fact, recently started the BGF Circular Economy Fund, with the Ellen MacArthur Foundation, to scope out start-ups that help big brands think differently about their products. (Its $20 million investment is tiny, but it’s something.)

That topic is coming up more frequently with the most unexpected of leaders. For example, in a recent meeting I had with the Starbucks chief executive, Kevin Johnson (who was a longtime Microsoft executive), the main line of discussion was around tech solutions to climate change. While banning plastic straws is all well and good, Mr. Johnson sees a bigger role in bolstering his company’s bottom line by focusing on sustainability (and also on the health of his workers).

Of course, none of this makes a difference unless alternative low- and no-carbon energy solutions are pushed forward over oil and gas. In this arena, the United States and Europe lag in investment and innovation far behind China, which has a staggering lead in solar photovoltaic module production and also a big head start in other renewable technologies, including hydropower and lithium-ion batteries. (Lithium, by the way, is often referred to as the “white petroleum.”)

So, this week at the economic forum in Davos, Switzerland, where a big focus was on the existential threat to humanity posed by climate change, it was more than depressing to see the climate change denier in chief, Donald Trump, attack what he called “prophets of doom,” presumably referring to activists like Greta Thunberg, who was also in attendance.