- Picture a world where giant vacuums are built in remote landscapes, sucking billions of tons of toxic greenhouse gases straight from the air and storing it safely deep underground.

This is part of the net zero future that scientists, policymakers, and entrepreneurs fantasize about.

Removing atmospheric carbon dioxide could be essential to making the planet livable for future generations.

We're likely to see huge developments in the next few decades, but the question is, is this really our solution to climate change, or is it just another excuse to let fossil fuel companies keep on trucking?

I'm Sinead Bovell, and this is Far Out.

[upbeat music] Climate change is doing weird things to the weather.

We're breaking records every year and not the good kind.

Record high temperatures, more hurricanes, floods, droughts, wildfires, these are just a fraction of the devastating impacts we're already experiencing.

A huge factor, carbon emissions.

Since the Industrial Revolution, we've raised atmospheric carbon dioxide by 50%.

This chemical compound traps the sun's heat in the atmosphere, trading a greenhouse effect across the planet, increasing temperatures everywhere.

- We could accidentally wreck human civilization and put the biosphere into a completely different status.

- That's renowned sci-fi writer Kim Stanley Robinson.

He spent years researching a future in which humans adapt to climate change.

- In your mind, imagine an ice-free planet, much higher sea level, lots of jungle and desert, completely different biomes.

And life will persist, but human life will be hammered.

- In 2016, world leaders got together to try and figure out how to slow down the pace of increasing temperatures.

The big concept they settle on was something called global net zero emissions, or net zero for short.

The basic idea is for every ton of carbon dioxide we emit, we remove a ton from the atmosphere.

Picture a bathtub, the water level in the tub is the amount of carbon dioxide in the atmosphere, and the spout is the amount we're currently emitting.

In a perfect world, we could stop emitting the carbon dioxide, but we know that's not gonna happen anytime soon.

So to keep the water level in the bathtub the same we need a drain, and that drain is a process called carbon dioxide removal.

Carbon dioxide removal comes in many different forms.

And amazingly, the Earth already does a decent job of it.

Forests and wetlands are, what scientists call, carbon sinks because of their ability to absorb atmospheric carbon dioxide.

Plants capture the carbon dioxide through photosynthesis, and store it in their biomass, and in the soil.

But when it comes to storing carbon, there's something that's even better than forests, the ocean.

- Already, the ocean has taken up about 26% of all of the carbon dioxide that human activities have released by a combination of both chemical and physical processes.

- That's Sarah Cooley, an ocean carbon cycle expert.

Right now, she's researching something called ocean fertilization.

- Ocean fertilization methods really seek to plus up an area of the ocean with a nutrient that's missing.

Sometimes it's iron, or it's nitrogen, or some other essential nutrient that is missing from that particular place in the ocean to encourage phytoplankton growth.

And phytoplankton are the single-celled, free living plants that fill the oceans.

It's almost like an approach the gardener would take to their garden, "What is my soil missing "and how can I boost it to encourage growth?"

- Phytoplankton are really good at capturing carbon dioxide, and by fertilizing the upper levels of the ocean with nutrients, we can stimulate their growth, and increase the ocean's capabilities as a carbon sink.

In 2022, Congress passed an infrastructure bill that included $3.5 billion in funding for a technology called direct air capture facilities, AKA, the giant vacuums.

They're basically giant fans that suck in air and treat it with a chemical that separates and traps carbon.

The trapped carbon can then be transported deep underground, where it can stay for thousands of years.

It could also be used as a raw material in a variety of products from commercial flooring to aviation fuel.

But none of this will matter if we don't turn off the spout.

So the big question is, will these techno fixes distract us from the more important goal of simply reducing emissions?

Well, we need some kind of carbon dioxide removal to clean up the emissions that are already in the atmosphere.

- That's what carbon removal really needs to be about, is figuring out how do we mop up those legacy emissions?

The things hanging around from like your grandma's Oldsmobile, you know, from 1985, they're still out there in the atmosphere.

- Carbon dioxide removal isn't the only wide scale tool we have to combat climate change.

In fact, there's a whole branch of research dedicated to ideas like this.

It's called geoengineering, which is an umbrella term for intentional large scale intervention in the Earth's climate system.

Geoengineering covers everything from building underwater walls to slow down glacial melting, to blasting chemicals into the air to reflect sunlight back into space.

We're at the point where we'll likely need these big ideas to help in the fight against climate change, but we just don't know what the long-term effects will be of some of these projects.

- Geoengineering is too broad of a term.

It's describing all kinds of interventions that are not commensurate with each other, that can't be bundled, and discussed intelligibly.

So we need to dispense with that word, or use it as a category and take it one technique at a time, and really grill those techniques, and keep an open mind because we are entering into a must break glass and do something moment of history.

- We need more research on these tools.

But much of that research is happening behind closed doors, and by the very same companies perpetuating the problem: fossil fuel interests and large scale financial institutions.

- We wouldn't trust companies that make cigarettes anymore to also fix the problem of cancer.

- That's Marion Gee, she works with dozens of grassroots environmental organizations.

- I think that this is the same setup here is that a lot of these tax credits, a lot of these monies are flowing to fossil fuel companies to clean up their own mess.

They've known for decades and decades, and they continue to rake in billions of dollars of profits.

- Fossil fuel companies don't have a great track record of taking care of the planet, and now we're expecting them to help make the world a healthier, more equitable place?

- We're focusing a lot of time, and energy, and resources on unproven technology that requires a lot of energy, and we've already seen, really hazardous effects on BIPOC communities.

There was a CO2 pipeline rupture recently in Mississippi that resulted in 49 people being hospitalized with serious symptoms.

- Time is running out as we continue to debate the solutions, we can embrace a case by case approach, one that deploys a portfolio of carbon dioxide removal initiatives, carefully considering local populations, vulnerable ecosystems, and future generations.

We can also try to work within existing systems, finding new and creative ways to capture and store carbon dioxide, and we need to keep focusing on how we can reduce carbon emissions altogether.

However we decide to move forward, we have to do it quickly.

[upbeat music]