Our built environment is a significant source of climate emissions. According to the construction industry's low-carbon road map, emissions from the built environment are approximately 17 Mt-CO per year2 i.e. almost a third of Finland's climate emissions.
One sub-set that often comes up is the manufacturing emissions of building materials. According to the road map, their total amount is about 2 Mt-CO2 per year, i.e. four percent of our total emissions.
Emissions from construction are being curbed with regulations to be included in the construction regulations, which will set limit values for carbon emissions from construction in the future. The legislator has not kept it a secret that in practice it aims to replace concrete with lower carbon materials, especially in apartment buildings and other large-scale construction.
Of course, emissions can be reduced slightly by changing materials, but the scale is very modest. This is due to the fact that the majority, three quarters, of concrete is used in areas where it cannot be replaced by other materials.
In the next few years, about four million square meters of concrete building stock of high-rise buildings will be built in Finland. Based on the investigations carried out, it is known that in this type of construction, material changes can produce around 80...90 kg-CO during the construction phase2emission reduction per square meter. Therefore, approximately 0,15 Mt-CO would be achievable with the materials2/a emission reduction, if concrete were to be completely replaced in at least every other construction site. Our emission reduction through these means would therefore be a rather modest 0,3%.
In addition to the fact that material substitution does not come close to our emission reduction goals, we also get negative side effects at the same time, such as the changing of the structures of wet spaces to an increasingly large part made of moisture-resistant materials, to name just one example.
If, instead, we invested in the low carbonization of cement and concrete, we could aim for a clearly greater and faster emission reduction, because then CO2cutter for all concrete construction. At the same time, we would also avoid the unpleasant side effects of the currently planned regulation.
Through the low carbon content of concrete, we could also combat climate change significantly cheaper than changing materials. In the most recently implemented example sites, the price of a ton of carbon dioxide saved by material changes has been staggering, around €2.500. Emission compensations approved by the UN and widely used talk about €10 per ton.
For example, the Norwegian government's recently launched so-called To the Langskip climate project, which supports clean technology projects with significant sums. Langskip's "main prize" was awarded to the Norcem cement factory, which is becoming the world's most climate-friendly cement factory. The costs of the low-carbonization technology of the cement it uses are estimated to be around €100...150 per ton of carbon dioxide, which is clearly less than one-tenth of the costs caused by material exchange.
The emissions of our domestic cement have already been reduced by more than 20%. Development could be accelerated significantly, but it does not happen on market terms, but requires the support of society. If even half of the society's support allocated to low-carbon materials were directed to low-carbon domestic cement production, we would achieve multiple emission reductions at much lower costs.
Jussi Mattila
CEO
Betoniteollisuus ry
The text has been published slightly formatted Rakennuslehten On the Näkökulma column on 13.11.2020 November XNUMX.
Write a comment