Read the headlines about climate change (or even just turn on The Weather Channel) and it's easy to start feeling pessimistic about the future of our planet. But while it would be foolish to ignore the increasingly alarmed warnings of scientists, there is reason to hope. 

First, because hope is a political choice. No one ever takes action unless they choose to believe things can be turned around. But second, because humans are incredibly ingenious tool-making animals, and some of the smartest among us are hard at work finding tech tools that can help us avoid climate catastrophe.  

Which isn't to say we can keep on spewing CO2 into the atmosphere at our current rate and invent our way out of the problem. Experts agree on that. But an increasing number of them have also come around to the idea that technology to capture carbon out of the atmosphere or eliminate it as a byproduct in industrial processes will be an essential piece of the puzzle

Entrepreneurs, as ever, are dreaming big to find these solutions. And, as ever, when humanity tries to do something new and daring, these entrepreneurs face serious headwinds. VCs, burned by earlier failures in clean tech, have been reluctant to invest in the sector, though there are a few exceptions.

"Total funding for clean-tech startups fell during most of the past decade, according to data from the research firm Pitchbook. In 2018, $6.6 billion was invested in clean tech, about 15 percent of what went to software startups. Carbon-removal startups got a tiny sliver of that," reports The New York Times

However, as fears of climate change grow, more money is starting to flow into the sector. Oil and gas companies have also filled some of the gap in funding, and top accelerator Y Combinator also recently put out a call for founders working on carbon capture to apply.

Adding to the problem, capturing carbon affordably and without a huge expenditure of energy is only half the challenge. Once you get it out of the air, how do you turn it into a profit-making product? Without obviously lucrative commercial uses, companies are reliant on government funding, and counting on a steady policy from the government is always a risky proposition. 

Entrepreneurs answering yes.

Still, despite these challenges, the payoff of success would be huge: not just a solid business but a more stable climate and a healthier earth for all us. Lured by these impressive upsides, an increasing number of startups are daring the choppy waters of the clean-tech business. Here are a few. 

This Bill Gates-backed Canadian company "pulls carbon dioxide out of the air by running it through specially formulated chemicals," says the same The New York Times article. It recently raised $68 million to build its first commercial facility.

According to The Times, this company "burns plant biomass to create hydrogen, capturing the greenhouse gases that are produced in the process." 

This Swiss startup "uses something called 'Direct Air Capture' to remove carbon dioxide from the atmosphere with what is, essentially, a large air filter that bonds to carbon dioxide," explains AngelList

A New York-based rival to Carbon Engineering, "it previously raised $42M in three rounds from 2010-17, is in the middle of a new $20M fundraising round," the Financial Times reports

These two companies "manufacture building materials--bioplastics and cement-free concrete, respectively--that are carbon negative, meaning the process to manufacture them removes carbon from the atmosphere," says AngelList. 

This startup has "created a device that stirs up water in the ocean to promote the growth of phytoplankton, which are algae that can take carbon dioxide out of the air and deliver it to the bottom of the sea in solid form," reports The Times

This nonprofit is thinking big, aiming "to cover shelf seas with volcanic rock, the weathering of which will, in theory, remove carbon from the atmosphere," says AngelList.  

This Y Combinator-backed startup is trying to build a machine "that creates usable gas from thin air--rather than the oil deposits deep underground," says Bloomberg. That would be impressive. 

"Plans to build a pilot project that can capture 100 metric tons of carbon dioxide per day, and eventually develop full-scale plants capable of removing nearly 4 million tons each year," reports MIT Technology Review

10. Visolis

This startup sounds like something out of a sci-fi novel: it's working on creating carbon-eating microbes.