Global warming changes both nature and the built environment – today’s engineers need to pay attention to future challenges


Global warming changes both nature and the built environment – today’s engineers need to pay attention to future challenges

7 June 2018
Climate change affects the planning of the built environment: when the weather and nature are changing, construction and things such as water supply and land usage need to take the changes into account. Invasive species are an example of the changes in nature that affect the built environment and the everyday lives and safety of people.

International free trade and the ballast waters of ships have brought new species to Finland over the years. Despite this, it is only with global warming in the 21st century that the fauna and flora in Finland has started to change at an unprecedented speed.

Climate change creates optimal conditions for new species that can compete for living space effectively. Invasive species can also impact the built environment, particularly the industrial plants located on the coast.

“We can expect trouble at the seaside industrial plants that depend on condensation water,” says Tarja Ojala, Sweco’s environmental specialist and biologist. “When rainfall increases and the salt concentration of the Baltic Sea decreases, the number of freshwater species, such as the zebra mussel, starts growing in the Gulf of Finland. The zebra mussel is a prime example of a species that can attach itself to almost any surface and forms large colonies, which can block the condensation and maintenance water pipes in the same way as dead plants.”

Changes in nature affect land use and water supply

Rising sea levels and temperate winters are other phenomena caused by the changes in nature, introducing entirely new challenges to engineering. 

“Climate change increases rainfall and the volume of drainage water, and temperate winters cause the temperatures in Southern Finland to fluctuate between sub-zero and above-zero temperatures. In this case, drainage waters may not be able to leave the ground if the drains are covered in ice. New measurements and plans are needed both for controlling drainage waters and constructing roads and other infrastructure. We may need floodbanks and culverts in places where they haven’t previously been necessary,” Ojala says.

When planning land use, future projects need to pay more attention to the ecosystem services produced by forests and the protection of diverse tree and habitat structures in urban forests, since strong and healthy habitats help keep urban environments safe for the residents.

“Due to global warming, deciduous trees will become more common and they will be exposed to new pests. When the growing season becomes longer, pest insects can produce two new generations in a summer instead of one, which will lead to increased storm damage, since the trees damaged by pests are more likely to fall down,” Ojala continues.

Focus on the ecosystem services offered by nature

Human life and wellbeing require functional ecosystems. These immaterial and material advantages produced by nature are called ecosystem services.

“Changes caused by humans directly impact the ecosystem services on which we are totally dependent,” Ojala states. “The production services of the ecosystem include the production of food, wood-based construction materials and clean water. Cultural ecosystem services include the recreational use of forests. Nature also offers services that maintain life itself, such as the photosynthesis of plants and forests acting as carbon sinks.”

Because of their significance, ecosystem services should be taken into consideration in all types of planning.

“It’s easiest to consider ecosystem services when planning land use, but the value of nature should be recognised in all kinds of planning and operations, from zoning to demolition,” Ojala says.

Responsible use of natural materials is a part of circular economy

Sometimes ecosystem services are lost, particularly when using land, which is why it is important to compensate for the impacts on nature. This can be done through effective collaboration between different engineering and design parties.

“Even though saving natural materials is critical, it’s just as important to consider how the consumption of natural resources could be compensated and how the used ecosystem services could be replaced. For example, a former field can be replaced with a carbon-binding forest, rainwater can be retained with green roofs and natural water drainage systems can be utilised more effectively.”

The best type of circular economy is when you reuse everything you can.

“All circular economy solutions save natural resources,” Ojala says. “As for land use, material efficiency could be taking rock and sand materials from another construction site and not from a natural esker. In construction, there are plenty of opportunities to reuse the materials produced on-site and reduce waste.”

It is important that the construction industry protects the species that have a critical role in the ecosystem, such as the kelp on the Finnish coast. Preserving trees is also worth it, as forests and swamps act as carbon sinks and make for local recreational areas that are also important for people in the cities.

“The more diverse nature stays, the better it can withstand any changes,” Ojala says. “Invasive species are not necessarily dangerous, but they can cause a lot of trouble at residential or recreational areas. Natural diversity is needed for wellbeing in the future as well, and we need to put more effort into preserving it.”