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How much carbon dioxide is produced by concrete?

By February 25, 2022 No Comments
hand holdig big tree growing on green background that shows how much carbon dioxide is produced by concrete.

How much carbon dioxide is produced by concrete? This question and others like it are increasingly important as we all work to ensure a sustainable future for our communities.

Let’s look at the details.

Carbon dioxide (CO2) is a naturally occurring gas in the Earth’s atmosphere. This gas, and other greenhouse gases, help to retain the heat from the sun and create our life-sustaining environment. Without them, our planet’s average annual temperature would be below freezing, instead of about 60 degrees fahrenheit.

However, when there is an unnatural increase in greenhouse gases, the delicate balance of the atmosphere is changed.

With this post, we aim to acknowledge our role in CO2 production and outline the vast importance of maintaining sustainable business and production practices.

Carbon Dioxide and Concrete

Concrete is created by mixing cement, water, and an aggregate (sand, gravel, etc.). It is important to note that the majority of CO2 emissions from concrete occurs during the cement production process.

Cement production is very energy-intensive, meaning that it requires a large amount of resources and power to create. A paper from the Portland Cement Association claims that the emission distribution of cement is as follows:

  • Combustion (40% of emissions)
  • Calcination (60% of emissions)

The carbon dioxide generated from the combustion process is mainly due to fuel usage. In the calcination stage, it is due to the heating of raw materials — usually limestone and clay. Heating them to extreme temperatures causes CO2 to release.

Despite cement’s environmental impacts, concrete is actually an incredibly CO2-efficient and sustainable construction material.

Sections of concrete that are exposed to air slowly absorb CO2 over their lifetime. Around 60% of the CO2 that was released due to the calcination process will be reabsorbed.

The numbers

The Portland Cement Association states that for every pound of cement produced, 0.9 pounds of CO2 is generated. Cement is only one ingredient in the manufacturing of concrete. Collectively, one cubic yard (about 3,900 pounds) of concrete produces roughly 400 pounds of carbon dioxide.

To put things into perspective, 400 pounds of CO2 is equivalent to:

  • Burning through an average tank of gas in a car
  • Using a home computer for a year
  • Replacing nine light bulbs in an average house with compact fluorescent light bulb
  • Using a microwave oven in a home for a year

Why does it matter?

As previously stated, carbon dioxide is a greenhouse gas. When levels of greenhouse gases in the atmosphere increase, our ecosystems are thrown off balance.

With global expansion and increased urbanization, we have been consistently emitting more and more CO2 over time. The National Oceanic and Atmospheric Administration states that despite the pandemic, the global average of CO2 levels in the atmosphere hit a record high in 2020. For the past 60 years, the annual rate of atmospheric CO2 has been increasing around 100 times faster than previous natural fluctuations.

Additionally, carbon dioxide is absorbed by the ocean. It reacts with water molecules and produces an acid that lowers the ocean’s pH (increases acidity). Since the industrial revolution, its pH has dropped by 0.1.

At first glance, that number might not seem that bad. However, because the pH scale is logarithmic, it is actually a 30% increase in activity. This ocean acidification interferes with marine life and has contributed to coral bleaching.

This evidence shows the need for change and increased sustainability.

Harms of Carbon Dioxide Emissions

Since carbon dioxide helps to trap and retain heat, an excess of CO2 can cause global temperatures to rise. According to NASA, average global temperatures have risen 1.4 degrees Fahrenheit since 1880, and they won’t be stopping soon.

Because the ocean helps to absorb heat, temperature increases don’t happen instantly. The current amount of carbon dioxide in the atmosphere will eventually cause an increase of about 0.6 degrees. Beyond that, future increases will depend on our actions.

Our fragile ecosystems do not react well to changes from the norm, no matter how small they seem.

The temperature increase has slowly begun to extend the growing season of plants. The combination of increased heat, droughts, and stress make the plants more susceptible to fire and insects. Forests are already burning more frequently in the far north.

Mitigating the Effects

Focusing on creating and maintaining sustainable practices is key to combating climate change.

Because we know that greenhouse gas emissions are largely due to human activities, we have the power to reduce emissions.

Sustainable development, reducing fossil fuel consumption, and protecting our environment are all ways that we can cut down on global emissions.

Our Commitment to Sustainability

Columbia Precast Products recognizes the importance of maintaining a sustainable practice.

We are committed to using sustainable practices and sourcing our materials locally. One of the ways that we commit to the environment is by carefully choosing who we partner with. Our cement manufacturer has a recognized environmental management system, and the company that supplied our mixing plant uses green energy and sustainable practices.

Our partnerships, sustainable practices, and dedication led us to be awarded a SMaRT certificate. We were the first precast plant in the buried infrastructure industry to receive this certification.

  • Our concrete pipe and precast products are made of entirely natural and raw materials and are Volatile Organic Compound (VOC) free
  • They are chemically inert
  • Our products have the longest life cycle of any product for sewer, water, utility, and storm drain systems

Our team of dedicated experts looks forward to serving you and the planet.