Most proposals to limit global temperature rises to well below 2° Celsius rely on ‘negative emissions’ – the removal of carbon from the atmosphere.
This can be done naturally, such as by protecting and restoring degraded forests so they become carbon sinks. Some also claim that it can be done through geo-engineering, for instance by burning bioenergy, capturing the carbon released, and pumping it into underground geological reservoirs. This is known as Bioenergy, Carbon, Capture and Storage (BECCS).
Fern believes there are three main risks in relying on geo-engineering projects:
- They are used as an excuse to keep burning fossil fuels despite unproven benefits
- They will have unacceptable ecological and social impacts if used at an industrial scale
- They cannot ensure stored carbon is not released through human or natural forces, including climate change