The UK must do more to remove CO2 from the atmosphere if we are to meet Paris Agreement targets and slow climate change, says a major new report.

Carbon neutral refers to net zero carbon dioxide (CO2) emissions – offsetting what is emitted by removing it from the atmosphere.

The authors of the new report estimate that the UK could cut new emissions of CO2 from 468m tonnes in 2016 to 130m tonnes in 2050 through decarbonising the economy – but that this presents an enormous challenge.

Techniques range from the well-known and ready-to-deploy, like planting more trees and expanding forests, to more speculative methods like direct air capture, which uses chemical processes to remove CO2 from the atmosphere. Professor Nilay Shah Department of Chemical Engineering

Removing CO2 will help the UK meet its Paris Agreement targets – a set of greenhouse gas reduction goals agreed by most countries in 2015.

The report, written by experts at the University of Oxford, Royal Academy of Engineering, Royal Society, and Imperial College London, argues that just reducing emissions is not enough, and that we need to proactively remove CO2 from the atmosphere.

The authors detail how we could use 'ramp up' existing greenhouse gas removal (GGR) methods to meet the goal.

Co-author Professor Nilay Shah from Imperial’s Department of Chemical Engineering, said: "Techniques range from the well-known and ready-to-deploy, like planting more trees and expanding forests, to more speculative methods like direct air capture, which uses chemical processes to remove CO2 from the atmosphere."

The authors say by taking advantage of and increasing the use of these existing methods, the UK can continue its leading role in combating climate change.

Professor Shah added: “No single technology alone can do enough to limit the effects of climate change, but our report highlights the greenhouse gas removal technologies required to let us meet the Paris Agreement goals.”

Methods to reduce atmospheric CO2 include:

• Planting new trees, restoring wetland and forest habitats, and adding nutrients and alkalinity to oceans. These methods increase the amount of CO2 removed from the atmosphere by photosynthesis.
• Bioenergy with carbon capture and storage, which captures CO2 from biomass power plants, transports it to a storage site, and deposits it where it will not enter the atmosphere.
• Agricultural methods, including helping soil to absorb CO2 during crop
  rotation and adding biochar, or burned biomass, to the soil to help stabilise organic matter and prevent it from releasing CO2. Another method is spreading ground silicate rocks on farmland to increase CO2 absorption.

The authors say most of these technologies are well developed and proven to help, but that to make them work for the Paris Agreement, governments should:

• Continue to reduce emissions of greenhouse gases, but recognise that removing greenhouse gases is equally as important.
• Encourage global adoption of the above GGR technologies.
• Build carbon capture and storage infrastructure, and encourage farmers to allow storage on their land.
• Establish incentives for businesses – for example carbon pricing to pay for CO2 removal.
• Build GGR into regulatory frameworks and carbon trading systems.
• Establish international science-based standards for monitoring the effectiveness of GGR methods and their environmental impacts.

"Using these methods at a large enough scale will be challenging, and will need a concerted effort from engineers, scientists and government. We must act now."

Professor Shah said: “Using these methods at a large enough scale will be challenging, and will need a concerted effort from engineers, scientists and government. We must act now.”

The report is the first time that a range of GGR technologies have been assessed for their real-world potential in being used together to meet climate goals in the UK over the next 30 years.

Professor Gideon Henderson, Professor of Earth Science at the University of Oxford and chair of the report working group, said: “If the UK acts now on greenhouse gas removal, we can reach national emissions targets and show how a major industrialised economy can play a leading role in meeting the goals of the Paris Agreement.

“We must absolutely continue to prioritise rapid cuts in greenhouse gas emissions, but we will also have to use these GGR methods to achieve international climate goals, and steward the planet for future generations.”

The report was commissioned by the Department for Business, Energy and Industrial Strategy.

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