Forests and soil: carbon sinks under pressure
Forests, both below and above ground, represent a key element in climate change mitigation strategies. But they are currently under increasing pressure, due to the impacts of human activities and the effects of global warming, says CMCC’s Lucia Perugini.
Forests play a crucial role as a natural carbon sink, actively contributing to our efforts in combating climate change. However, these invaluable ecosystems face increasing pressures, including higher harvest demands and the escalating impacts of climate change-induced natural disturbances.
The crucial role of forests in climate change mitigation is highlighted in the Paris Agreement, and is recognised by the European Union as a crucial step towards reaching its climate targets.
The EU Forest Strategy 2030 is a comprehensive approach designed to increase the quantity and quality of natural carbon sinks throughout Europe, through afforestation programs and the prevention of deforestation. Moreover, the EU has implemented a novel regulation for land use (LULUCF) which aims to enhance the forest carbon sink by an estimated 42 million tonnes of CO2 equivalents by 2030 compared to 2016-2018. LULUCF plays a key role in this endeavor by introducing targets and enforcing enhanced monitoring requirements for all EU member states.
However, it is important to acknowledge that the forest carbon sink has its limitations and cannot be expanded indefinitely, nor can it serve as a sole substitute for reducing emissions in other sectors.
“This is indeed a challenging target,” said Lucia Perugini, of CMCC’s Impacts on Agriculture, Forests and Ecosystem Services (IAFES) division. “The forests in Europe are aging, and facing a lot of pressure from natural disturbances. If you look at the projections, the forest sink is either stable or decreasing.”
In an interview with FLUXES, Perugini points out that increasing the forest sink is needed to counterbalance emissions that are hard to abate, such as emissions from agriculture. To incentivise forest owners to increase their carbon sinks, the EU is developing a regulation for carbon removal certification.
Agriculture accounts for approximately 11% of the greenhouse gas emissions in the European Union. This percentage is significant due to two major emissions, namely nitrous oxide and methane, as potent greenhouse gases. Farming practices that address these agricultural emissions are often referred to as carbon farming, and they include focussing on the role of soils, crucial for the implementation of nature-based climate solutions.
The recently introduced EU regulation on Carbon Removal Certification defines carbon farming as the process of storing carbon in the soil and vegetation, including bushes or trees, to mitigate climate change.
“The new LULUCF regulation puts pressure to increase the land-based carbon sinks, so the EU Commission proposes the certification as an incentive system for the land managers,” said Lucia Perugini in another interview with FLUXES, focusing on carbon farming.
According to FLUXES, a transparent and standardised system must be put in place for the Carbon Removal Certification regulation to work. “The regulation says that carbon removals need to be based on measurements and quantified, but the methodologies are still under development,” explains Perugini, who is a member of the Expert Group on Carbon Removals established by the European Commission.
ICOS has great potential for this work, Perugini says: “ICOS can help us to understand what are the effects of different management systems and practices in different conditions. For instance, how much cover crops affect the carbon sink, or what is the magnitude of possible side-effects. ICOS could also develop a baseline for certain types of soil or forest sinks. When the sinks are certified, they undergo a verification process to check whether the results are within the acceptable ranges. ICOS could provide external verification information.”
Dr Perugini ponders that ICOS could participate in building an emission factor repository on the changes in agricultural practices, to provide data for the farmers for their decision-making. “And certainly, ICOS can help greatly to understand the year-to-year and seasonal variations caused by weather to the soil carbon dynamics. Even though the farmer would do everything by the book for five years, but then a very dry year comes, destroying yields and carbon values. Then what happens?”
The permanence of the increased soil carbon stock is one of the key issues, as it is highly uncertain. It depends very much on weather variability, and on the future actions of the land managers.
The Integrated Carbon Observation System (ICOS) is a European-wide greenhouse gas research infrastructure. ICOS produces standardised data on greenhouse gas concentrations in the atmosphere, as well as on carbon fluxes between the atmosphere, the earth and oceans. This information is being used by scientists as well as by decision makers in predicting and mitigating climate change. The high-quality and open ICOS data is based on the measurements from over 168 stations across 16 European countries.
FLUXES, the European Greenhouse Gas Bulletin, is a publication by ICOS, the Integrated Carbon Observation System, which aims at highlighting climate issues to an audience of policymakers, policy advisors, and climate journalists.
The interviews to Lucia Perugini appeared on the following original articles by FLUXES: