Carbon Capture - More than just planting trees

When talking about taking carbon out of the atmosphere, most people’s first thought is planting trees. But this is actually only one of many methods of capturing carbon, and one that is not always particularly efficient or permanent.

Planting forests is seen as a low-cost and easy way for businesses to be able to put a ‘carbon-neutral’ sticker on their products, and has sparked a plethora of reforestation projects across the globe. While many of these will indeed help reduce atmospheric carbon and improve their environment, a poorly planned tree-planting project can actually do more harm than good.

One of the main problems seen in afforestation programmes is whether trees should even be there in the first place. Some landscapes, such as peat bogs, are better long-term stores of carbon than forests are, and so planting on or near these habitats can impact their delicate structure and make them release carbon instead of absorbing it. There is also an impact on agriculture, forests planted in arid areas like the African savannah may replace some of the little fertile land in these landscapes, or require too many resources or maintenance to be cost-effective. In some cases, the forest may not be looked after once it's been planted, meaning trees can end up felled in storms or from illegal logging, releasing the carbon straight back into the atmosphere.

So is carbon capture pointless? Not at all!

The clean tech market has expanded hugely in recent years, and a host of carbon capture technologies exist that provide permanent greenhouse gas removal. Our favourite of these (can you guess?) is microalgae. Microalgae is responsible for producing about 75% of the world’s oxygen, and are very efficient at photosynthesis. Some microalgae carbon capture technology can absorb CO2 at a rate 400x more effective than trees. Algae are small, dense, and can grow in a range of environments, from seawater to agricultural sludge. One of their benefits is their versatility, they can be grown in open ponds to absorb carbon out of the atmosphere, or hooked up to an industry’s emissions to directly capture the company’s carbon before it reaches the atmosphere.

All carbon capture methods have their benefits and drawbacks, and in order to make a real contribution to stopping climate change, we will need to use a combination of multiple methods, optimising them for the environments they will be used in.