28,000 football fields
Christiane Weihe
Every single day in Germany, land disappears under residential buildings, supermarkets or roads. On average, 55 hectares per day are sacrificed for housing developments and transport infrastructure. The equivalent of 78 football fields is covered up day after day after day. Things are no different in the rest of Europe, with an area greater than the size of Budapest getting sealed every year. Between 2012 and 2018 alone, 539 square kilometres of arable land and semi-natural or natural areas were lost. This has consequences for biodiversity and soil quality, among other things, and also for the climate. What approaches could help to curb this far too high level of land consumption? The Oeko-Institut is doing the research.
By 2030, the German Federal Government aims to reduce new land consumption to less than 30 hectares per day, as has been set out in the National Sustainability Strategy since 2016. According to the Climate Protection Plan, the aim is to even get to "net zero" land consumption by 2050 − in other words, a fully circular land economy. The EU has also set itself the same target in its Roadmap to a Resource Efficient Europe. "Such ambitious targets are good and important. But we must now also urgently consider how they are to be achieved," says Franziska Wolff of the Oeko-Institut.
The constant decline in open spaces is a major problem: These areas are no longer available for growing food and they can no longer absorb greenhouse gases. Moreover, sealed surfaces increase the risk of flooding. Landscapes get dissected and valuable habitats for flora and fauna are lost. As a result of urban sprawl, infrastructure becomes less utilised, resulting in higher servicing costs per individual. But why are we still consuming so much new land in the first place, when the country’s population is stagnating? "Private households are taking up more and more space and businesses want to expand into new locations," says Franziska Wolff, who heads the Environmental Law & Governance Division. "In addition, municipalities often have tax incentives to attract businesses and new residents. In contrast, land saving or land recycling and the associated possibilities for protecting the environment, climate and resources are not sufficiently taken into account in planning processes. Overall there seems to be as yet little political will to spare land.
New options
It is true that new land consumption is lower now than it was at the turn of the millennium − between the mid-1990s and the 2000s, more than 100 hectares disappeared every day under settlements and transport infrastructure. "But this far from resolves the issue. Existing efforts are not sufficient to achieve a circular land economy by 2050." For example, the Federal Nature Conservation Act contains an impact mitigation provision: where there is an unavoidable intervention in nature, this must be mitigated or offset by means of substitution or financial compensation. "But these provisions are of questionable functionality. After all, compensation does not create new, natural soil. Moreover, there is no obligation to remove impermeable surfaces or restore soils. And even if impermeable surfaces are unsealed, their former high ecological value cannot be restored," says Tobias Wagner, Senior Researcher at the Oeko-Institut.
In the project entitled “Handlungsoptionen zum Erreichen des europäischen Flächensparziels Netto-Null” (Options for action to achieve the European no net land take target), the Oeko-Institut is currently working together with the Helmholtz Centre for Environmental Research on the question of how land saving targets can be operationalised and achieved. The project team is screening ongoing European-level activities on land sparing and soil protection for the German Environment Agency. "These include information systems and research projects, but also political instruments and implementation activities," says Franziska Wolff. "We analyse these activities and assess their relevance." Among these are, for example, the Copernicus Land Monitoring Service, which provides data on Europe’s terrestrial areas, or the partnership on sustainable land use and nature-based solutions as part of the EU's Urban Agenda. "The partnership has developed a plan of actions on land-use indicators and how they should be taken into account in impact assessment processes. It also covers financing mechanisms for the rehabilitation of industrial sites, ways to identify and manage unused land and options for the reduction of urban sprawl. From our point of view, the action plan contains many interesting approaches." In addition, the scientists summarised individual measures taken in the EU Member States. Luxembourg, for example, is considering tradable land certificates; in the Austrian “climate check”, land use also plays a role in environmental assessments; in Poland, the principle of a circular land economy and compensation for new land take were included in the National Spatial Development Concept 2030. "Some countries have already set quantified land saving targets. Others have not, and much work still needs to be done on operationalising such targets." The Commission's draft EU Soil Health Act of early July 2023 also does not include obligations for Member States to set land saving targets and underpin these with the requisite measures. "It is to be hoped that over the coming months the draft will signal greater ambition with regard to the land issue. Otherwise it will be difficult to achieve the ‘no net land take’ target."
Based on its analyses, the project team will support the German Environment Agency in the upcoming European dialogue. "Through several European workshops, our aim is to improve cooperation on this very complex challenge, which is also handled in very different ways across Europe." Choosing land protection over land take also contributes to climate change mitigation. In the project entitled “THG-Minderungspotenziale durch Flächensparen” (GHG reduction potential of reduced land take) for the German Environment Agency, the Oeko-Institut is therefore analysing the impact of land consumption on greenhouse gas emissions. "If less land is used, carbon sinks are preserved," says project manager Tobias Wagner. "Moreover, the construction of fewer settlements or less transport infrastructure further entails resource and additional greenhouse gas emissions savings." So far, however, there has been very little awareness of the greenhouse gas effects of land consumption − and also insufficient expertise. "Planners in cities and municipalities cannot readily quantify the greenhouse gas effects of new land take; they simply lack the tools to do so. Therefore, they usually do not take these effects into account."
Greater awareness in the municipalities
In order to create awareness among communities of the major impact of their actions and at the same time provide them with easily understood guidance, the scientists are currently developing a method that identifies and visualises the potential for greenhouse gas reductions from avoided land take. One focus is on the changes that occur in the soils’ carbon stocks and vegetation. Together with the Gertz Gutsche Rümenapp – Stadtentwicklung und Mobilität GbR consultancy, the Oeko-Institut also looks at the emissions that result from the construction and use of buildings and infrastructure. "For example, just for the soil’s excavation we assume a loss of 11 per cent of the carbon stored therein, even if the excavated material is only temporarily stored for the period of the construction works," Wagner explains. We already know that external development, such as the construction of new buildings on previously vacant land, generally has a greater impact on the environment and climate than internal development, where, for example, extra floors are added to existing buildings or buildings are reconstructed after demolition with more usable space in the same footprint.
The experts have already prepared a status report on the current state of knowledge and are now working on the calculation method. When the project is completed next year, they want to be able to calculate the level of potential greenhouse gas savings for every hectare that is not converted, down in scale to the level of the approximately 11,000 municipalities in Germany.
"We already gained many exciting insights in the course of the project to date," says the Oeko-Institut scientist. "For example, the major impact mechanisms in land conversion are becoming apparent, as well as many indirect effects." He recalls the “plate-or-tank” debate, which dealt with the fact that the cultivation of maize or rapeseed for biofuel generation, for example, means that less land is available for food production in this country − and that the land needed to provide food is then taken up elsewhere in the world. "With new land take, I see a similar causal chain − only the trigger is different." Changes to surfaces, such as impervious sealing with asphalt, also have an impact on climate, he notes. "It's called the albedo effect. When sunlight hits a white ice surface or even green areas, it is reflected more strongly than, say, from dark asphalt. This too has an influence on global warming."
Time for a rethink
Tobias Wagner hopes that showing decision-makers and planners in cities and municipalities the effects of expanding transport and settlement areas can lead to a rethink and perhaps even a reorientation of political action. "If we can clearly show municipalities the amount of greenhouse gases they are causing through their land consumption, this will hopefully persuade some of them to take land into account in their planning as an important resource of conservation concern that deserves their attention."
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Franziska Wolff heads the Environmental Law & Governance Division at the Oeko-Institut, dealing with international, European and German environmental policy. One focus is on sustainable land use. Tobias Wagner is a senior researcher in the Resources & Mobility Division. His remit includes life cycle assessments and greenhouse gas balances as well as environmental assessments of land consumption.