Sewage Treatment for the Skies

The mitigation of climate change to limit global warming to well below 2°C, as specified in the Paris Agreement, builds on two pillars. The first pillar, supported by most stakeholders but facing implementation challenges, is rapid and deep reduction of greenhouse gas (GHG) emissions from burning of fossil fuels and destruction of forests and other types of biomass. The second pillar, contested by many but increasingly seen as crucial, is carbon dioxide removal (CDR), i.e. the practice of actively removing CO2 from the atmosphere and durably storing it1 . Both pillars complement each other in the quest to achieve greenhouse gas-neutrality, a balance of emissions and removals.