The Terrestrial Carbon Sink

TLDR

Life on Earth is built on carbon, which is essential for biology and climate regulation, and its continuous exchange between ecosystems and the environment has led to an increased terrestrial carbon sink. The study reviews the biological processes that govern the terrestrial carbon sink and how they depend on climate, atmospheric composition, and human interventions. The authors synthesize existing research on the biological mechanisms driving the terrestrial carbon sink and their sensitivity to climate, atmospheric composition, and anthropogenic activities. The terrestrial carbon sink has removed an estimated 3.61 Pg C yr⁻¹ (≈33.7 % of anthropogenic emissions) over 2007–2016, providing a valuable ecosystem service that has significantly slowed climate change.

Abstract

Life on Earth comes in many forms, but all life-forms share a common element in carbon. It is the basic building block of biology, and by trapping radiation it also plays an important role in maintaining the Earth's atmosphere at a temperature hospitable to life. Like all matter, carbon can neither be created nor destroyed, but instead is continuously exchanged between ecosystems and the environment through a complex combination of physics and biology. In recent decades, these exchanges have led to an increased accumulation of carbon on the land surface: the terrestrial carbon sink. Over the past 10 years (2007–2016) the sink has removed an estimated 3.61 Pg C year −1 from the atmosphere, which amounts to 33.7% of total anthropogenic emissions from industrial activity and land-use change. This sink constitutes a valuable ecosystem service, which has significantly slowed the rate of climate change. Here, we review current understanding of the underlying biological processes that govern the terrestrial carbon sink and their dependence on climate, atmospheric composition, and human interventions.