While terms like sustainability and climate protection are now topics of intense discussion in the building sector and frequently receive attention at major meetings in industry, the topic of biodiversity is yet to become part of everyday life among companies. At the DGNB Annual Congress 2023, biodiversity expert Dr Frauke Fischer, Pascal Bunk (Knauf Gypsum) and Sven Schulz (Lake Constance Foundation) explained why this is becoming a problem. They also discussed potential solutions to the growing biodiversity crisis.
BLOG SERIES ON THE DGNB ANNUAL CONGRESS 2023 (PART 2)
The second digital annual congress of the DGNB took place on 14 and 15 February. The event featured a variety of open discussions, providing plenty of ideas and inspiration on different aspects of sustainable building. This series of blog posts offers a look back at the event with a summary of key insights. In our next post we focus on the topic of climate change.
The topic of biodiversity often brings to mind another term: species diversity. The terms are often used synonymously, although species diversity is only one level of biodiversity. The other two are genetic diversity and ecosystems diversity. To kick off her keynote speech, Dr Frauke Fischer emphasised the degree to which humankind influences all three levels.
The big human footprint
“Over the past 50 years, we have destroyed nearly 70 per cent of all vertebrate populations and nearly 80 per cent of all insects, with the result that many species have become extremely rare. This immediately heightens the risk of extinction for those species,” the biodiversity expert explained. “We’ve also accelerated species extinction – by a factor of roughly 1000. This means we must assume that every hour, one or two animal or plant species are disappearing forever.” Finding true wilderness has also become very difficult, she explained, with only about two per cent of Earth’s land mass as yet untouched by human activity.
Having outlined the context, the biologist went on to highlight that 2020 was probably the year when for the first time, there were more man-made things on Earth than things of nature. This also includes the building sector. Measured by weight, in 2020 our buildings and infrastructure exceeded the total biomass of all trees and shrubs on Earth.
Why the loss of biodiversity is such a problematic issue
Humans derive benefit from nature. This is mainly thanks to so-called ecosystem services, which include the purification of water and air, as well as the availability of fertile soil for producing food. And then there are the things in life we consider relaxing or appealing, plus things humans make use of for recreational reasons, such as hiking through the mountains or going for a walk in the woods. “With all of these ecosystem services, we can, for example, not replace them at all, or only do that inadequately – but it’s always extremely expensive, and it’s never without causing further damage,” explained Fischer. According to calculations made in 2011, the economic benefits of ecosystem services alone amount to more than €100 trillion. So whichever country you look at, whatever the survey period, this is always just under double the gross national product of that country.
Besides financial factors, the biodiversity crisis also involves a number of fundamental issues of an existential nature. During her presentation, Fischer described loss of biodiversity as like ‘screws dropping off an aeroplane in flight’. It may not be terrible when the first screw wriggles free, or even the second, third or fourth. But at some point, she explained, it’s one screw too many and down goes the plane.
Protecting biodiversity and saving the climate
This is why it’s all the more important to protect biodiversity by introducing effective measures now. Renaturation was described by the expert as a particularly promising measure in this respect, not only because it promotes or restores biodiversity, but also because it’s good for the climate. As she explained, there are currently 350 million hectares of degraded land on Earth. Renaturing that amount of land by 2030 would remove just under 26 gigatons of greenhouse gases from the atmosphere. That would be almost exactly the emissions gap in 2030 on the path to achieving the 1.5°C target set by the community of states, as well as targets that could be achieved through political measures and current activities.
Seizing opportunities in the building sector
Whereas Dr Frauke Fischer came at the building sector from a somewhat critical angle, Sven Schulz of the Lake Constance Foundation saw the potential offered by towns and cities. According to Schulz, some cities have even become refuges for species that struggle to find natural habitats elsewhere. He did, however, also emphasise the value of renaturation measures or enhancements to the biological status of land surfaces.
Given the need to mitigate the harm done by raw material extraction, Pascal Bunk, biodiversity manager at gypsum producer Knauf, highlighted how important it is to extract raw materials in Germany – and on a broader scale: in the EU. Legal guidelines are extremely tight in this area and companies cannot simply leave gaping holes in the countryside when open-pit mining is no longer viable. This unveils an opportunity to renature or recultivate open-pit mines and leave behind biotopes that are even more diverse than before the sites were chosen for mining. Such measures offer particularly strong potential in areas of arable and cultivated land in Central Europe, especially when it comes to creating positive impacts on biodiversity.
In a discussion on the topic of raw materials with moderator Dr Christine Lemaitre (DGNB), Sven Schulz and Pascal Bunk also described circular building as a bone of contention for the industry, especially with respect to biodiversity loss. At present, they said, resource consumption is still far too intense for the limitations of this planet to meet demand. Gypsum manufacturer Knauf believes there is still of lot of catching up to do in raw material recycling, especially given that in the foreseeable future, gypsum will no longer be available as a by-product of coal combustion, so it will have to be sourced elsewhere.
To listen to all discussions at the DGNB Annual Congress 2023, as well as the keynote speech, tune in to the DGNB YouTube channel. For more information on DGNB’s involvement in biodiversity protection, click here.