The term carbon footprint is defined as: ”The total amount of greenhouse gases produced to ,directly and indirectly, support human activities, usually expressed in equivalent tons of carbon dioxide (CO2)” — [Time for Change]. Every person, community, organization, industry and product have a carbon footprint, which cumulatively affects atmospheric processes, and driving global climate change. We need to be able to quantify these contributions so that we can actively formulate a strategy to reduce our carbon footprint and the negative impact it has on the environment, our planet, and ultimately our wellbeing.
Concrete by numbers?
The construction industry is one of the largest contributors of atmospheric carbon dioxide, with concrete alone responsible for up to 7% of all anthropogenic carbon emissions. Carbon dioxide is released as a byproduct when limestone (calcium carbonate) is heated to produce cement — a key component of concrete — and also as a result of energy consumption during manufacturing and transport process of concrete.
According to the International Energy Agency, the cement industry is the third largest consumer of energy in the industrial sector globally, consuming 7% of all energy used in the industrial sector.
Concrete, and by association, cement is widely used in all forms of construction from commercial, to residential, and other forms of infrastructure that we all utilize on a daily basis, such as waterfronts, and coastal defense structures. As global human population continues to rise, along with increasing urbanization, cement production is expected to increase by up to 23% by 2050. Much of this development will occur along the coastline which are highly effected by climate change, where concrete already accounts for more than 70% of all coastal and marine infrastructure.
A concrete problem!
Yet, while concrete is strong and designed to withstand the extremely harsh conditions found in coastal environments, its biological and ecological performance in coastal and marine environments is very poor. This is mainly due to the smooth, homogeneous surfaces it offers, and due to its aggressive chemical composition. As a result, concrete structures typically support low diversity of marine life, with poor biological productivity. As a result, opportunistic and invasive species rapidly colonize and take over the space, often with dire ecological, and economic consequences.
However, innovative entrepreneurs, who typically view a problem as an opportunity, are stepping up with creative solutions to address and offset the carbon footprint associated with concrete. For example, a Canadian startup, CarbonCure, have developed an innovative method of producing concrete that traps carbon dioxide emissions and binds it within the concrete forever, while at the same time reducing the amount of cement used to make concrete.
Nanotek on the other hand, developed revolutionary technology in sustainable cement production. They transform Portland cement into Nano cement. The technology gives the opportunity to reduce CO2, NOX, and SO2 emissions by 2-3 times per ton of cement and have production cost savings of over 30%. Their Nanotechnology results in high-performance cement and concrete, that are more sustainable, and do not call for heavy reconstruction of cement facilities.
ECOncrete® tackles the pain from a different, ecological angle. The company, founded by two marine biologists, has developed innovative technologies to reduce the carbon footprint of concrete based urban, coastal and marine infrastructure. ECOncrete’s technologies reduce the carbon footprint in a different, dual, manner. Instead of absorbing CO2 directly, ECOncrete® produces a patented nearly zero carbon admix that integrates recycled and reuse materials. The admix typically replaces 10% of the cement in the concrete mix, and when used in combination of slag cement and supplementary cementitious materials that have a lower carbon footprint than Portland cement, can reduce over 80% of the carbon footprint of the concrete. Moreover, the admix, alongside with ECOncrete®’s science-based technology enhance marine life and encourages natural processes like calcification and photosynthesis, that uptake CO2. Thus ECOncrete® improves the ecological performance of concrete seawalls, breakwaters and alike by promoting biodiversity rather than reducing it. This has several positive spin-offs, including promotion CO2 sequestration in the marine environment through biogenic growth by corals, oysters, tube worms and alike, and by enhancing algal growth that increases photosynthetic activity on the structure. Apart from the ecological advantages, ECOncrete®’s technology also improves the strength and durability of the concrete. This is achieved directly through application its patented admix, increasing the concrete’s compressive strength and reducing its sensitivity to corrosion, and indirectly, through Bioprotection, a natural process where marine growth (especially that of calcifying organisms that also double as a carbon sink) protects the concrete from erosion and chloride penetration.
The oceans play a key role in the natural carbon cycle, with carbon dioxide moving from the atmosphere into the oceans across the ocean-atmosphere interface. As carbon dioxide is found in higher concentrations in the atmosphere, it is readily absorbed by the oceans, which traditionally act as a carbon sink, removing around 30% of man-made carbon dioxide from the atmosphere. Dissolved carbon dioxide is assimilated by phytoplankton and marine algae (seaweed and kelp) during the process of photosynthesis, and carbonate ions (calcium carbonate) are synthesized by zooplankton and other marine organisms, such as snails, shellfish and corals, to build shells and skeletons. While high concentrations of CO2 may be beneficial to photosynthesizing phytoplankton and marine algae if sunlight and nutrients are freely available, it can chemically react with seawater to form carbonic acid, leading to ocean acidification, which can be harmful to other marine life.
By providing a suitable substrate that encourages growth of marine plants and animals, which in turn provide habitat for a diverse range of marine organisms, including urchins, whelks, bivalves and other shelled organisms, carbon dioxide is naturally assimilated into the oceans, eventually sinking to the ocean floor when these organisms die. ECOncrete®‘s innovative solution also contributes to these processes by bringing concrete infrastructure to life, generating rich and diverse urban marine habitats teeming with fish, oysters, sponges and alike. ECOncrete®’s modified concrete also encourages growth of engineering species such as oysters, corals, and barnacles, whose calcium carbonate skeletons not only acts as a sink for carbon dioxide, but also increase the strength and durability of concrete structures to which they adhere.
Recognizing that both the carbon footprint and ecological impacts from the shipping and maritime industry are significant in the busy waters of the Mediterranean, the NEREIDAS project was launched in an effort to find solutions to reduce CO2 emissions and increase biodiversity, in Spanish ports through cultivation of seagrasses, as a vector for carbon sequestration. Following this, in order to address the increasing need in construction of new infrastructure in Mediterranean ports, these days, ECOncrete® is working with three Spanish ports (Melilla, Cartagena, and Vigo), developing a series of demonstration projects integrating bio-enhancing concrete into port infrastructures as a part of a comprehensive scheme for carbon reduction in Spanish Ports.
Climate change is a man-made problem, and as such can be mitigated by humans if we have the will and collectively make an effort to address it. It just requires a little bit of creative thinking and a lot of positive action. Innovative technologies, such as these, that provide sustainable solutions can have positive global impacts that benefit the environment, the planet and everyone and everything that lives on it.