The carbon cycle in the era of global change and the contribution of biomass to the sustainability goals

Abstract

Biological processes represent the major driving forces in the global carbon (C) cycle. The extent of anthropogenic CO₂ release threatens our future and is not tolerable. The increase in atmospheric CO₂ reflects the cumulative effect of human activities over more than a century and must be stopped. The contribution of photosynthesis to the binding of excess CO₂ could be increased if other limitations such as limited N- and P-availability were overcome. The productivity of various types of vegetation increases upon application of fertilizers. However, N-fertilization jeopardizes natural biomes, alters the rhizosphere, decreases the biodiversity and stimulates the release of potent greenhouse gases such as CH₄ and N₂O. Therefore, fertilization must be restricted and fails as global solution to increase CO₂ binding in biomass in context of climate action. Worldwide afforestation appears a powerful action. However, its capacity to reduce CO₂ is sometimes overestimated. The consequences of afforestation on land use change, conservation of natural biomes, crop food prices and socio-economic traditions need to be considered. High priority must be given to the reduction of CO₂ emission by combustion. In addition, there is urgent need to technically develop and economically implement negative emission technologies. Decisions in context of climate actions must be placed in the framework of all sustainable development goals including no poverty and no hunger.