Carbon sinks: the great destocking

The experts emphasized the importance of marine and terrestrial ecosystems in climate regulation, and their role in buffering greenhouse gas emissions. In recent years, these ecosystems have been experiencing a collapse as carbon sinks. Since 2016, the efficiency of forest and ocean sinks has been declining. We emit 10 billion tonnes of CO2 a year, 1/4 of which is absorbed by the oceans and 1/3 by the terrestrial biosphere, but half remains in the atmosphere, warming the climate and saturating carbon sinks.

European and Amazonian forests have lost their carbon storage capacity, with some becoming carbon-neutral or even carbon-emitting, notably due to droughts and fires. In eastern France, trees weakened by extreme summer heat are falling sick and releasing Co2. Global CO2 absorption by forests has fallen from 25% to just 5%. In the Amazon, the El Niño phenomenon of recent years has caused devastating droughts, destroying 33% of the remaining forest between July 2023 and 2024. Replanting trees, especially monocultures, is not a sustainable solution. Fostering biodiversity is crucial to forest resilience.

As for the oceans, they are suffering from acidification and warming, reducing their capacity to absorb CO2, which could fall by 20% in the coming years. A slowdown in cold deep-sea currents is also suspected. It is difficult to protect the oceans without reducing emissions.

These various ecosystems can only continue to fulfill their role as carbon sinks if we reduce our emissions in excess of what they are capable of absorbing. The longer we wait to achieve this balance, the more these ecosystems will degrade and become less and less efficient, leaving us with fewer and fewer options to continue emitting CO₂ in a NetZero scenario !