This is the third and final post of our series discussing how concrete can affect the planet and how to preserve it. Part 1, How Does Concrete Affect the Planet?, discussed how concrete – including cement production – can impact resources, like water and energy. Part 2, How Does Concrete Affect the Planet? Recycling and Reuse, discussed recycling and reusing concrete.

Along with harmful environmental effects, cement production also creates air pollution from the emissions of carbon dioxide (CO2) created during the process. CO2 is a greenhouse gas that traps heat in the atmosphere and contributes to global warming. Cement manufacturing emits approximately 5% of global man-made CO2 emissions, as much CO2 as produced by all the cars in Europe!

However, don’t blame your concrete for this one! The chemical reaction that takes place when cement mixes with water to form concrete releases CO2. So even if you use recycled or reused concrete components (aka aggregate), this reaction will still occur. But there are ways to reduce this impact.

Cement producers have already made great strides in reducing CO2 emissions. In 2010, they came together to form the Cement Sustainability Initiative as part of the World Business Council for Sustainable Development. They agreed to a program

Concrete is the second most consumed substance on Earth after water. Because of its components, concrete has a large carbon footprint other than just making cement.

How Concrete Causes Pollution?

Concrete is the second most used material on Earth after water. It is a primary building block of our infrastructure and is made from common natural materials such as limestone, clay, sand and/or shale. Concrete production requires significant energy input, most of which is derived from fossil fuel combustion. Concrete production also releases carbon dioxide, a greenhouse gas that contributes to global warming. Therefore, concrete usage has significant environmental impacts.

The impact of concrete production on global warming is significant. The production of cement (an ingredient in concrete) releases high amounts of CO2 into the atmosphere. Shown below are the relative contributions of various building materials to global warming (measured in kg CO2-equivalent per kg of material).

Concrete can be an environmentally friendly construction material, but it does have its fair share of drawbacks. To begin with, concrete production uses a great deal of energy and natural resources. Producing one ton of cement, the primary ingredient in concrete, requires 4.7 million BTUs of energy, about equivalent to the energy produced by burning more than 400 pounds of coal. The industry also emits large amounts of carbon dioxide into the atmosphere, which is believed to contribute to global warming and other climate-related issues. Concrete production is also a major source of air pollution in the United States, emitting more than 100 million tons annually.

Fortunately, there are some fairly simple ways to reduce the impact that concrete has on the environment. One way this can be accomplished is by reducing the amount of cement used in any given project. Although not as strong as concrete made with portland cement (the most commonly used ingredient), concrete made with fly ash has similar durability and can significantly reduce greenhouse gas emissions associated with its production. Recycled plastic or glass fibers can also be added to concrete to improve its strength and durability while requiring less cement.

In addition to reducing greenhouse gas emissions during production, some concrete also contains recycled materials that would otherwise end up in a landfill. In fact,

Concrete is a basic building block of our everyday lives. It’s in homes, buildings, roads, bridges and more. Look around you and you’ll see concrete structures everywhere. But have you ever wondered what goes into making that concrete? The world produces more than 4 billion cubic yards of concrete each year, and it’s the second most consumed substance on Earth after water. On the surface, this doesn’t seem like such a bad thing — but as with most things, there are two sides to every story.

Concrete production has a variety of negative effects on the environment, including air pollution (CO2), water pollution, destruction of habitats and loss of biodiversity. But there are also some positive effects on the environment that are worth noting – such as the fact that concrete can be recycled and that concrete is an inherently strong building material which has a long life span (in excess of 100 years) to minimize replacement needs.

Concrete is a very versatile and widely used building material, with an estimated global production of approximately 10 billion tons per year. Concrete is the second most consumed substance on Earth after water, and it can be found nearly everywhere.

Concrete is a mixture of paste and aggregates (sand & rock). The paste, composed of cement and water, hardens and binds the aggregates into a rocklike mass. This process is called hydration.

The manufacture and use of concrete produce a wide range of environmental impacts, such as global warming potential, acidification potential, eutrophication potential and photochemical ozone creation potential. In addition to the release of CO2 during the production of cement (a key ingredient in concrete), concrete also functions as a large carbon sink upon its use. Concrete absorbs CO2 from the atmosphere during its service life, which makes concrete one of the most environmentally friendly building materials available today.

Concrete’s ability to store carbon dioxide makes it a tool for combating climate change. By replacing other building materials with concrete, we are able to reduce emissions related to resource extraction and transportation associated with those materials.

Concrete, a mixture of sand and gravel (aggregate), water, and cement, is the world’s most widely used man-made product. It is used more than any other material, including steel and aluminum combined. There are many challenges to the sustainable production and use of concrete. These challenges include:

The depletion of natural resources such as high quality aggregate, sand, and gravel;

The depletion of fossil fuels used to mine, process and transport raw materials;

The emissions from the use of fossil fuels to produce cement;

The release of carbon dioxide from cement production;

According to the USGS 2009 Minerals Yearbook, in 2007 the worldwide production of concrete was approximately 10.8 billion tonnes (11.9 billion short tons). As a result, concrete usage accounts for approximately 5% of global CO2 emissions. This amount is comparable to the total emissions from all the cars in the world.