Climate change is the defining issue of our generation, and the construction industry will play a key role in leading the global community towards reducing carbon emissions. Carbon reduction is no longer an option or an impossibility, it is a necessity.
According to the Intergovernmental Panel on Climate Change (IPCC) Special Report, human-induced global warming reached approximately 1°C above pre-industrial levels in 2017. If this trend continues and global temperatures exceed the 1.5°C mark, we can anticipate irreversible damage to our ecosystems and our overall quality of life.
The impact on my personal lifestyle involves the elimination of activities such as skiing or snowboarding, but for other locations around the world, it makes the difference between life, death and survival. The 2019 UN climate change report states that, to limit global warming to less than 1.5°C, we need to reduce carbon dioxide (CO2) emissions by 45% by 2030 and achieve emissions neutrality by 2050. This seems like a daunting task, but the alternative of not meeting these targets will be catastrophic for both our ecosystems and the global economy.
When assessing economic value through the prism of shareholder value, the benefits of becoming greener are becoming clear. The increase in ESG (environmental, social and governance) investment since 2005 has been significant. Today, ESG investment is estimated at $20 trillion or 1/4 of all professionally managed assets. In addition, some studies estimate that shares in sustainable companies significantly outperform their non-sustainable competitors. This reflects a broader and growing buying trend, where in 2014 55% of consumers will pay extra based on positive environmental or social impacts.
How is our industry contributing to climate change?
It is imperative to comprehensively recognize the impact humans have on climate change before devising a roadmap to net-zero emissions. Currently, the construction industry accounts for 39% of global carbon emissions, which means that the changes we make will have a fundamental impact around the world and could represent the tipping point between success and failure.
A fully decarbonized sector could reduce almost half of all carbon emissions in the atmosphere. So where do we currently stand in reaching this target? Looking at final energy demand in buildings from 2017 to 2018, demand increased by 1% and 7% since 2010. Population growth can be attributed to a large increase in demand. And, as our global population approaches 10 billion, the international building stock is expected to double. Unless our sector drastically changes the way it operates, this growth will consume vast amounts of natural resources and could contribute to an expected doubling of global raw material consumption.
Before delving deeper, there are two key categories of carbon emissions that we need to understand:
Carbono operativo
Carbono incorporado
what is operational carbon? Operational carbon describes the emissions that result from keeping the building running, such as keeping the lights on and the building cool. Operational carbon accounts for 28% of our carbon emissions. On the other hand, the building life cycle itself accounts for 11% of carbon emissions. The good news is that our industry is starting to move toward lower operational impacts and green buildings. In addition, the benefits of green building are starting to be recognized by building owners. To say the least, this trend should continue. Some of the benefits attributable to green buildings include:
Lower operating costs
Increased value of assets
Providing healthier and safer environments for occupants
Demonstrate the owner's commitment to environmental stewardship and social responsibility
What is embodied carbon?
Embodied carbon is the sum of all greenhouse gas emissions (mainly carbon) resulting from the construction life cycle of a building. This includes emissions from the extraction and transportation of materials, the construction phase, building maintenance activities (such as renovation), and ultimately the end-of-life stage through demolition and disposal or processing of materials.
To date, very few projects focus on reducing embodied carbon emissions or achieving net zero emissions. However, given that 11% of carbon emissions result from these activities, this is where the construction industry needs to prioritize its efforts. Unfortunately, the impacts of embodied carbon are less well understood, and this article will focus on these impacts and the steps we can take to reduce our contributions.
Currently, there is a lack of incentives or requirements to achieve net zero embodied carbon emissions, but this is slowly beginning to change. For example, in 2016, the City of Vancouver released its Zero Emissions Buildings Plan setting specific targets and actions to achieve zero emissions in all new buildings by 2030.
However, we cannot wait for legislation to mandate embodied carbon reduction. We must act as stewards of our industry and effect positive change now.
5 steps to reduce embodied carbon
The World Green Building Council has provided a detailed report on how our industry can reduce our embodied carbon footprint. I have summarized five (5) of these key steps below:
Measuring embodied carbon emissions
Across the industry, we need to measure our embodied carbon emissions across the entire construction lifecycle.
Establish a baseline
Once we understand the extent of our emissions, we can use this as a benchmark for setting reduction targets and, ultimately, a path to net zero carbon. Our current contributions and reduction targets must be publicly available to ensure that we are accountable.
Adopt best practices
Our industry will need to take concrete steps toward reduction targets. For contractors, this will involve disclosure of supply chain data and selection of materials based on lowest embodied carbon impacts. This will require greater adoption of Environmental Product Declarations (EPDs) from material manufacturers to be used in the selection process
Designing with a low-carbon approach in mind
Designers should adopt a fully integrated Life Cycle Assessment (LCA) approach to all design decisions. This approach not only considers a low-carbon approach to design, but also other aspects of project performance, such as material, water and energy needs throughout the life cycle.
Lead by example
Asset owners will need to lead by example by requiring all projects to have net zero embodied carbon. This will require changing the way we approach supplier and partner selection and even financing projects to put our environmental impact at the forefront.
What can I do as an owner?
Building owners and developers have a crucial role to play in driving our industry toward net zero embodied carbon. Owners can bring this issue to the forefront of the design and decision-making process by specifying:
Exclusive use of low-carbon materials.
Designs that consider carbon reduction throughout the life cycle of the asset.
Requirements to reduce emissions during construction activities.
Owners should work with design teams to critically analyze the designs we are selecting and focus on those that prioritize carbon reduction. For the construction phase, work with your general contractors to incentivize carbon and waste reduction. Electric machinery is no longer a futuristic dream. Companies such as Caterpillar, Bobcat and Volvo, among others, have introduced electric machinery in recent years. Not only does electric machinery make it possible to achieve net zero, but it can also have positive health and safety implications by reducing worker interactions with toxic emissions.
Reducing rework and waste is also a critical element, and the financial incentives here are clear. According to an ENR article, rework costs can range from 2% to 20% of a project's total contract amount. If this is not reason enough for change, perhaps considering the resulting environmental impacts of wasted material, labor and additional transportation is. We need to prioritize upfront planning and improve communication between projects and stakeholders to reduce inefficiencies in our industry and pave the way to net zero carbon.
Owners can and should establish a roadmap to build only zero embodied carbon projects. For existing assets, the decision to renovate versus rebuild can have crucial impacts, in addition to ensuring correct operational frameworks to maximize the asset's useful life. Extending the operational life of a building or infrastructure asset through regular maintenance, reuse or refurbishment of existing assets and ultimately reducing end-of-life emissions through recycling will enable us to achieve net zero carbon.
Conclusion
As an industry, we have limited time to achieve ambitious goals; however, the alternative is no longer something I like to consider. The future of our environment and economic success depend on our collective efforts now and recognition of the magnitude of the problem we face.
The good news is that we can link a net-zero emissions strategy with the digital transformation of the construction industry. This will allow us to achieve efficiency and productivity gains that other industries have experienced, while creating sustainable jobs and new markets for future generations
Read more about BIM software solutions that support sustainable construction.
This article was originally created by Elliot Jones for E-builder, a Trimble company. It was also previously published at https://constructible.trimble.com/
