In 2011 the Green Deal on Concrete was signed by the Dutch ministries of Economic Affairs and Infrastructure & Environment (I&E) and 24 companies and 7 trade associations representing the concrete chain, cooperating in the Concrete Network, an informal collaboration under the banner of CSR Netherlands, an organization promoting Corporate Social Responsibility. This Green Deal is a statement of intent to render the concrete sector sustainable by the year 2050. Sector-wide negotiations are currently underway to finalize an agreement to this end, encompassing goals relating to CO2 emissions reduction, the circular economy, biodiversity and social aspects.
This study summarizes the knowledge accumulated in this process on ways to reduce the carbon footprint of the concrete chain. It does not aim at completeness, but rather to inspire companies and policy-makers to together explore which options can be realized by establishing a concrete agreement, and in doing so create opportunities for the future.
This report was prepared by CE Delft at the request of Rijkswaterstaat (an agency of I&E), one of the organizations participating in the Concrete Network. It describes 17 methods to reduce the carbon footprint of concrete. For each option it has been calculated how great an emissions reduction can potentially be achieved: the abatement potential, thereby taking two reference points:
- The technical potential for 2020 (i.e. what can safely be applied in 2020 if all parties collaborate on the required technology from now on).
- Calculated concrete use in 2010, so that the achieved reduction in carbon footprint can be compared with the figure for this reference year.
For each option the abatement costs were also calculated: what it costs to avoid one tonne of CO2 emissions, i.e. all additional costs of the greening option divided by the amount of CO2 that is no longer emitted, with both calculated over the full operational lifetime of the option.
There is also a certain amount of overlap in CO2 reduction between technologies. A range of different cement substitutes were studied, for example, and if one is implemented for all the concrete, the others are no longer feasible. We therefore also calculated a total abatement potential corrected for such overlap. The total cumulative abatement potential is 0.9-1.4 million tome (Mt) CO2. In 2010 total CO2 emissions stood at 3.7 Mt CO2.
Because a broad range of technologies were examined, from those in the initial pilot phase through to commercially available options, the maturity of the technologies was also assessed. The more mature a technology, the greater the probability of the calculated reduction potential being achieved. Based on this assessment of technological maturity, it can be concluded that:
- 0.1 Mt annual CO2 reduction is certain
- 0.6-0.8 Mt annual CO2 reduction is probable
- 0.3-0.5 Mt annual CO2 reduction is uncertain.
Overall, then, this means that 0.9 Mt annual CO2 reduction is likely from 2020 onwards, which is 24% of aggregate emissions in 2010.