In the fight against climate change, trees are an ally. They suck in carbon dioxide, reducing the harmful greenhouses gases in our air. But there’s a problem — we’re asking them to work overtime.

Trees can’t absorb enough of the carbon dioxide humanity is throwing at them, unless we turn every inch of available land into a dense forest, according to Christophe Jospe, the chief strategist at Arizona State’s Center for Negative Carbon Emissions.

But what if trees — or machines modeled after them — had superpowers? Artificial trees with otherworldly abilities are a great hope against climate change, as environmental experts say it’s not realistic to expect humanity to release significantly less carbon into the atmosphere. Our best bet may be to capture the excess carbon and store it or convert it into something useful such as fuel.

…what if trees — or machines modeled after them — had superpowers?

Five years ago, a Boston group recruited two designers to develop artificial city trees. The trees they envisioned offered shade and would absorb carbon dioxide. The thinking was to place the trees where soil was too shallow to host traditional trees.

The group delivered beautiful mock-ups, but so far little else has come from it. Finding funding is a challenge.

“You don’t want to be the first person to pay,” said Kimberly Poliquin, the director of SHIFTBoston. “Scientists have figures, but you don’t know if that’s going to be the reality once you built it.”