Why EU needs a carbon sink strategy to attain climate neutrality

Climate neutrality means more than just reducing greenhouse gas emissions. This became clear most recently when the European Commission suggested that emissions sinks should be included in its calculations for reaching a strengthened 2030 climate target, by including the effects of afforestation measures.

Climate neutrality means net-zero emissions. Not all emissions can be completely eliminated – for example, those caused by agriculture, heavy industry or shipping. Some way of compensating for these must therefore be found. Anthropogenic sources of greenhouse gases rightfully occupy a central position in the roadmap towards achieving climate neutrality. However, we must also get serious about preserving and expanding CO2 sinks; in other words, about capturing CO2 from the atmosphere and storing it permanently.

Conventional mitigation measures, such as energy efficiency and renewable energy deployment, are widely discussed in society and are supported by a multitude of analyses, studies and strategies. But we know relatively little about sinks and their potential. This subject should be approached systematically and strategically. Therefore, the EU needs a carbon sink strategy, and an accompanying roadmap, with detailed targets and implementation programmes.

How much sink capacity do we need to become climate neutral by 2050 – and to remain so afterwards? What kinds of sinks do we want? And how do we organise all this so that it also pays off economically?

Even a question like ‘how much?’ is not that easy to answer. Nobody can say for sure what the amount of ‘hard-to-abate’ residual emissions from agriculture, industry and aviation will be in the EU by mid-century. But even scenarios are lacking. To date, there is only one analysis available, published by the European Commission in 2018. Here, residual emissions reach 10% of 1990 values, while 90% of emissions can be mitigated using conventional emissions reduction measures. While 10% may not sound like a lot, it represents more than 500 million tonnes of CO2 equivalents annually. This is twice as much as is currently being removed from the atmosphere through afforestation and better forest management.

In the EU, there is a lot of experience with net CO2 removal through land use, land-use change and forestry (LULUCF) which is essential for climate neutrality. However, this experience also tells us that the exact measurement of CO2 removals via LULUCF is fraught with great uncertainty. Furthermore, the forests that have formed the most important sinks to-date are vulnerable to disturbances like heat stress, fires and pests. There is a real danger that the CO2 bound in trees and soils might escape into the atmosphere again later on. It is precisely for this reason that the sink capacity of forests has not been included in calculations for achieving EU climate targets to-date. There are good reasons to change this as we proceed towards climate neutrality. But we also require greater efforts and new concepts in this sector. This includes, for example, the issue of storing more CO2 in agricultural soils, or finding ways to clear forest areas sustainably if trees are no longer growing and thus not storing additional CO2 anymore. The increased use of wood as a long-lasting building material might be one solution to this.

However, there are also technological methods of capturing CO2 from the atmosphere. The one best known is direct air carbon capture and storage; it filters CO2 out of ambient air and combines it with geological storage. This process requires relatively little land and affords great flexibility in the choice of location. However, it needs a lot of energy and is still very expensive. So far there have only been a few pilot installations, and it is hardly possible to predict whether a massive expansion would result in cost reductions as dramatic as those in solar and wind power. Only limited potential is attributed to other processes such as biochar burial or deploying crushed minerals on soil or in coastal waters. Some of these may also face acceptance problems, depending on countries and locations of deployment. But just like with conventional emission reductions, we should not rely on one single technology for creating and expanding our CO2 sinks.

Expanding our knowledge base can help us to engage with this issue in a cool-headed manner – and only with structured processes and strategies, we will be able to make adequate progress. In order to make sustainable use of ecosystem-based or technological sinks, we require ambitious projects. On the one hand, the EU has an obligation here – not just because of its own target of climate neutrality by 2050, but also for reasons of global and historical responsibility. On the other hand, there are also opportunities in establishing technologies and processes that serve new markets, thereby creating jobs and prosperity.

Although it is true that there is a growing number of research programmes on CO2 removal, in climate policy the issue has been given hardly any consideration so far. If we intend to achieve climate neutrality in the EU’s economy over the next three decades, we will very soon need an initial idea of CO2 removal goals that we want to achieve by 2030, 2040 and 2050. This would give more structure to the transformation process, in which emission reductions and sink enhancements face different challenges. The IPCC has repeatedly pointed to the necessity of expanding CO2 sinks. Individual countries like the UK and Switzerland, or US states like California, have already begun to formulate strategies and even fund demonstration plants. As an established climate policy leader, it should be the EU’s aspiration not to remain on the sidelines any longer.