Direct air capture – Companies like Climeworks in Iceland (pictured) have built machines that they suck in air and filter out carbon dioxide using chemicals . The carbon dioxide can then be reused in other products or stored deep underground where it is mineralized. The US Department of Energy has announced investments in direct air capture in 2022 amounting to 3.5 billion dollars.

Bioenergy with Carbon Capture and Storage (BECCS) – Trees and plants draw carbon dioxide from the atmosphere and then burn it to produce energy, while the released carbon is captured and stored underground. BECCS is tested in facilities including power plant Drax in England and by International Energy Agency it is the only carbon dioxide removal technique that can also provide energy.

Mobile direct air capture – Zem - "zero emission mobility" - is a solar-powered electric car that includes two portable air filters . The filters are located next to the front wheels, and when air flows through them, the carbon dioxide sticks to the grain inside. The filters need to be emptied every 200 miles, and the solution is admittedly small-scale – currently the filters capture 2 kilograms (4.4 pounds) of CO2 every 20,000 miles.

Planting trees – Everyone knows that trees absorb carbon dioxide; is a key component of photosynthesis. Planting trees and restoring forests is technologically undemanding and cheap, but not without problems, such as planting monoculture forests and planting of non-native species – which is bad for biodiversity and reduces the trees' chances of long-term success . Plant for the Planet calculated that planting a trillion trees could be one of the most effective ways to combat climate change.

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