What is climate change?An easy to understand guide to climate change for construction specialists
Climate change explained: a guide for construction specialists
“We can’t address climate change without thinking about buildings.” — Bryn Davidson, Lanefab (Vancouver)
You have probably heard a lot about climate change, but do you know what it means exactly and why it might be of interest to you?
I sat down with one of our resident experts, Ms. Tytti Bruce, and asked her to explain what climate change is and what it means for the construction business. If you don’t know a lot about the subject hopefully you will find her answers as helpful as I did.
The first thing to understand when we talk about climate change is that changes in the average temperature of the planet have always occurred, but today when we talk about climate change we tend to refer to global warming as an effect of human actions. The climate is a complex phenomenon that is constantly affected by how much of the radiation emitted by the sun are reflected back to space, how much stays in our atmosphere, and how much reaches the ground.
While fluctuations in the average weather have always occurred, the question today is if the global climate is getting warmer rapidly and if such an increase of the average temperature can be attributed to human action.
By looking at all the different factors that affect how much of the sun’s radiation is trapped in our atmosphere rather than being reflected back to space, we can determine that there are a lot more factors warming up the planet than cooling it down.
Weather and climate are complex phenomena that are characterized by a lot of different variables and internal connections, making it hard to measure how much the planet is heating. However, we can safely deduce that the average temperature of the planet is rising and that this is caused by human actions.
For example, when greenhouses gases heat the planet, this causes a shortage of snow and ice, which leads to less sunlight being reflected back to space, therefore warming up the atmosphere. By looking at the studies conducted by climate researchers around the globe, we can see that almost 100% of them show results that predict that the climate will get warmer. Even more importantly, there is a clear consensus that the major causes behind the warming up of the planet are human.
1Source: U.S. National Climate Assessment (2014).
What are greenhouse gases?
Greenhouse gases are gases that trap heat into the atmosphere, therefore contributing to warming up the planet. It is important to point out that greenhouses gases are not inherently harmful, but when their presence in the atmosphere increases too much it leads to the rise of average temperatures worldwide. The most well known among greenhouses gases is carbon dioxide, but others are methane, chlorofluorocarbons, and ozone. The presence of greenhouses gases in our atmosphere has steadily increased since the Industrial revolution, mostly because of fossil fuels.
What is the greenhouse effect?
As the name exemplifies, it describes the phenomenon in which the heat generated by sunlight is trapped inside Earth´s atmosphere and cannot escape. This leads to average temperatures rising, in the same way as a greenhouse is always warm inside even when outside temperatures are dropping.
How do buildings cause climate change?
Fossil fuels, like coal, petroleum, and natural gas, were originally dead vegetation, that over the course of millions of years, have become fossilized and contain a high percentage of carbon. We burn fossil fuels to warm our houses, move our vehicles, and power our factories, and by doing so we release a lot of carbon dioxide and other gases that have a known impact on global warming. This is why renewable energies have become so important: fossil fuels are non-renewable, since it takes millions of years for dead plants to be transformed into coal, and using them as our only sources of energy is not sustainable, in the long run.
Buildings and construction are responsible for 39% of carbon emissions globally (read for example about US täällä and Europe here), out of which 28% from energy consumption and 11% from construction materials, also known as Embodied Carbon (data from World Green Building Council’s Bringing Embodied Carbon Upfront).
Building’s energy consumption comes from its need to warm up and cool down the structure, especially when the building has not been designed to be efficient in terms of insulation and ventilation.
Building’s embodied carbon comes from the manufacture and supply of construction products and materials, as well as the construction process itself.
Using fossil fuels to produce energy has a certified correlation to global warming. However, as the energy grid decarbonizes, it is clear that the next step in climate change action is to reduce buildings’ embodied carbon.
By reducing embodied carbon, we can limit the negative impacts on global warming caused by buildings.
The field of construction has been moving towards Net Zero Carbon buildings. A Net Zero Carbon building is a building that through the course building’s life-cycle greenhouse gas emissions from all sources sum up to zero, or less.
The next step is to build a net-positive or energy-positive building that produces more energy than it consumes and that can generate enough energy through its whole lifetime to make up for the energy used to construct it.
A good explanation of why net-positive buildings are the next frontier of green building is in this TED video:
The choice of construction materials, water usage, transportation are some of the other factors that should be taken into account when aiming for more sustainable building practices. This is why the use of Environmental Product Declaration and all-encompassing green building certification labels like Passive Houses has grown a lot over the last few years.
While green building practices can help reducing greenhouses gas emissions, net-positive buildings could help inverting the current trend regarding global warming.
At the same time, the more green building and ecodesign become mainstream, the more harmful practices are reduced at all levels.
Source: IPCC AR5
How can Building Life Cycle Assessment help fight Climate Change?
Carbon footprint measures how much CO2 has been released into the atmosphere as a consequence of specific actions or processes. By calculating a building’s carbon footprint, we have a clear overview of how much carbon dioxide our building will introduce into the atmosphere and therefore, how much we are contributing to global warming.
Performing a life-cycle assessment means to accurately measure carbon footprint, as well as other environmental impacts like ozone depletion and acidification, to get an accurate overview of how our building will affect the environment during its whole life-cycle.
Life-Cycle Assessment is a standards-based scientific methodology that objectively measures the environmental impact of a process, product, or service. By measuring Life-Cycle Assessment, you can determine which design choices will help reduce your building’s carbon footprint, which materials are causing more greenhouse emissions, and how to design greener and more efficient buildings based on reliable, quantifiable data.
Life-Cycle Assessment gives you the whole picture and is the best way to accurately calculate carbon footprint.
What can I do as a construction specialist?
Every human being on the planet will be affected by global temperatures raising, either directly or indirectly: many people will be displaced and become refugees, and changes in the weather will affect food supply chains, economic stability, population trends, and even the ubiquitousness of infective diseases like malaria. If we don’t act now, any corrective measures will be incredibly costly and largely ineffective.
The impact of global warming on the world’s economy has been thoroughly researched by many economists. For example, Diez and Stern (2014) point out that rising temperatures would lead to general impoverishment in their article “Endogenous growth, convexity of damages and climate risk: how Nordhaus’ framework supports deep cuts in carbon emissions” : “We show that, with the models extended in this way, business-as-usual trajectories of greenhouse gas emissions give rise to potentially large impacts on growth and prosperity in the future, especially after 2100.”
Without an immediate, global commitment to action, both short and long-term consequences will be dire. If you are a construction expert, you need to ask yourself what kind of future you want to build for and what kind of legacy you want to leave behind, for your children and your business.
If you work in the field of construction as an architect, designer, manufacturer, contractor, consultant or investor, you have the opportunity to contribute to shaping the world of tomorrow. By making smart design choices, evaluating materials more carefully, and relying on proven methodologies and metrics, you can find out which choices can result in buildings with a lower carbon footprint and use that information to continue improving your future projects.
While green building is an ethical commitment to a better future, it is also a sound financial choice, as the market demands more transparency, traceability, and accountability.
Whether you work with new buildings, refurbishments, and retrofit, infrastructure, green building certification schemes like LEED, BREEAM, DGNB, EPDs, or are just interested in learning more about ecodesign and sustainable buildings, we would be happy to help you.
One Click LCA is the easy to use and standards-based software that allows you to calculate Life-Cycle Assessment and Costing, Carbon footprint, EPDs for your materials or transition into ecodesign effortlessly.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 711303.