Nature-based solutions

On 28 June, the Policy Learning Platform hosted the second episode of the climate adaptation series, focusing on wetland restoration. 

During the webinar, we explored inspiring solutions, good practices, guidance and recommendations backed by real-life examples of wetland restoration in Belgium, Germany and Romania. 

Explore the recording, key learnings and presentations below. 

Tree planting is widely regarded as one of the solutions to climate change and carbon offsetting. The European Union has made a pledge to plant three billion trees by 2030 and published a new EU forest strategy. An important aspect is that the methodology of planting and growing needs to be fully respectful of ecological principles. This means that the right tree has to be planted in the right place and for the right purpose. The newly planted trees should be planted not only in forests but also in rural and urban areas.

Trees planted in cities, also called urban forests, have the ability to sequester carbon, provide shade and mitigate flooding. The results of a study from the Institute for Atmospheric and Climate Science, ETH Zurich suggest that larger groups of trees in cities can reduce surface temperature up to 12°C. Urban environments and paved surfaces cause several problems that inhibit proper growth of trees and many trees die before reaching an effective size. Planting methods are therefore crucial in ensuring the longevity and health of urban trees.

Common problems include:

• High inconsistency of water supply, often ranging from shortage to sudden floods.
• Impermeable surface and compressed soil, which limits distribution of water and oxygen in the root system. Suffocation and dying trees are often the result of these constraints.
• The plant beds are often too small for the root system, which reflects in poor development of the tree, and structural changes on the pavement.

When the City of Stockholm’s Traffic Administration made an overall status assessment of street trees in 2001, it showed that two-thirds of all trees in the inner city were dead or dying.

“About 20,000 street trees were dying because the city soils were lacking oxygen, water, and organic matter, plus a surplus of road salt, carbon dioxide, vehicle compaction, utility installation, and maintenance disruption were poisoning the trees.”

To recover existing trees, the city started testing various methods. As a result, a unique approach to urban tree planting has been developed.

The rise of heavy precipitation and extreme coastal water levels have increased the risk of river and coastal flooding in many European regions, which have been experiencing these events with increasing intensity over the past decades.

Health complications, death, disruption of services, destruction of infrastructure and housing, or access to clean water are some of the impacts flooding has had on millions of European citizens since 2000. “If no adaptation measures were taken, the number of people affected by coastal flooding in the EU at the end of the 21st century would range from 775 000 to 5.5 million people annually” (European Environment Agency, 2021).

Restoration supports rivers’ natural capacity to retain water and thus contributes to flood risk management. However, only around 40 % of the 110,000 bodies of surface water in the EU (i.e. rivers, lakes and transitional and coastal waters) are currently in good ecological shape, according to the European Environmental Agency (EEA).

In the past, floods were usually mitigated by constraining the watercourse, building dikes, straightening rivers to increase discharge and building artificial retention areas.

The new approach is based around natural restoration, and works with the recreation of meanders, wetlands, floodplains, and natural storage areas in the landscape. The method is in alignment with the EU Floods Directive, the Water Framework Directive and the Birds and Habitats Directives.

Nature-based solutions are considered a key component of several European strategies. The EU’s 2030 biodiversity strategy, a key pillar of the European Green Deal, includes a nature restoration plan that can boost the uptake of such solutions. Nature-based solutions are also highlighted in the EU strategy on climate change mitigation and adaptation that was recently adopted by the European Commission.

Adaptive solutions can take many forms, aside from the aforementioned flood mitigating river basin restoration, from green roofs and city-cooling green spaces to the planting of vegetation that stores carbon and stabilises coastlines.

The integration of nature-based solutions into municipal strategies is a pre-requisite for the effective restoration of rivers. A good practice presented in the EURE project highlights an approach from the Czech Republic that focused on environmental quality and environmental management efficiency of EU urban areas.

Forests are the safeguards of biodiversity, as they host 80% of biodiversity on the planet. They cover around 45% of Europe’s surface, making them the largest terrestrial ecosystem in the EU.

Forests provide essential ecosystem services and are important for climate protection through carbon sequestration, stability of water cycle, erosion prevention, protection of biodiversity and many other economic, environmental, and sociocultural ecosystem services.

In July 2021, the European Commission adopted the New EU Forest Strategy for 2030, a flagship initiative of the European Green Deal.