A carbon sink is a natural or artificial reservoir that captures and stores morecarbon than it releases. Examples include forests, oceans, soil and potentially timber buildings. We need these reservoirs to capture existing atmospheric carbon at the same time as we need to reduce our carbon emissions to turn off the tap and stop pouring in more carbon. 
 Gürdür Broo, D., Lamb, K., Juvenile Ehwi, R., Anneli Pärn, E., 2020. Four Futures, One Choice: Options for the Digital Built Britain of 2040. Researchgate.