Negative emissions refer to removing greenhouse gases (like CO2) from the atmosphere. It is common to hear about it in climate change discussions, as removing these gases can help mitigate the changing climate. For example, there is a need for negative emissions to keep global warming below the 1.5-degree target. In other words, lowering or stopping the emissions is not enough as GHG gases stay in the atmosphere for a long time.
Greenhouse gases will need to be captured and stored to achieve negative emissions. This process can happen in a natural way or with technical solutions.
Technics for negative emissions
One common technic to enable the above is called “Carbon Capture and Storage” – CCS. It is a technic that captures and stores greenhouse gases. Globally, there are about 20 functioning facilities of this kind today. The challenge is mainly that the technic is very expensive. Still, the International Energy Agency, IEA, states that about 6000 million tons of CO2 will need to be stored by the year 2050. More so, negative emissions stand for about 12 % of the collective efforts to reach the goals of the Paris Agreement.
Researchers have critiqued the public trust in technical solutions such as CCS for several reasons. In part because the technic enables people to keep mistreating the Earth without changing their lifestyles. To mitigate climate change, one cannot rely solely on technical fixes. Furthermore, binding more GHG gases is not a substitute for reducing emissions from human activities. It is a complementary measure to remove remaining emissions.
Natural solutions
There are many natural ways of creating negative emissions. The most obvious way is by creating more biomass, like planting more trees or algae in the ocean. Hence, reforestation and rewilding efforts are critical. These solutions bind greenhouse gases in nature.
Similar to geoengineering
Some of the technical solutions for negative emissions are similar to a concept called geoengineering, which is large-scale manipulation of the Earth’s climate. Geoengineering is a controversial subject relating to complex and global concerns. Due to the world’s inequalities, some fear that powerful nations would have more influence over the technics. It could create a “climate colonisation” where wealthier countries get a better climate than poorer ones.
Future outlook
Overall, achieving negative emissions on a large scale is both difficult and expensive. It is important to see it as a complementary measure to emission reductions, not a substitute to keep emitting GHG gases.
