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Using Lifecycle Thinking to Protect the Climate

One of the most difficult questions we face in the modern world is how to judge the impact our lives have on the world around us. Reducing our individual consumption of energy and natural resources is one clear way to make a positive difference. However when it comes to understanding which actions will actually help achieve this, the answers are rarely simple. This is where scientific research and investigation can play a vital role in helping everyone – whether a consumer, manufacturer or politician – identify the right choices to make.

Lifecycle thinking tells us that to understand the true impact of a product on the environment, we need to consider every stage of its existence. This could typically include extraction and production of raw materials (such as crude oil or metal ores), transport to production sites, production, transport to installation, installation, use, removal, transport to waste management facility (e.g. recycling plant), and recycling.

What we have today is a mass of different measurements and methods for calculating product impacts. Most people will be familiar with the carbon footprint, which measures greenhouse gas emissions associated with particular products or activities. A number of other calculation methodologies also exist, such as the water footprint, sustainability appraisal, social footprint and cradle-to-cradle certification. However many of these methodologies are flawed, for the reason that they only measure a very small number of environmental impacts, and not always across the entire lifecycle.

Lifecycle assessments (LCAs) are more rigorous tools to assess the environmental aspects and potential impacts associated with a product, process, or service. This involves compiling an inventory of relevant energy and material inputs and environmental releases, evaluating the potential environmental impacts associated with these inputs and releases, and interpreting the results.

This final stage – interpretation of results – is crucial in identifying the most important materials and choices for climate protection. To give an example, the materials used to construct vehicles determine how heavy they are. The heavier the vehicle, the more fuel it will burn, and the more carbon dioxide it will produce. Understanding the right mix of materials to reduce vehicle weight without compromising other aspects such as safety will therefore help protect the climate. On average 15-20% of materials used in the construction of a car are plastics. However, the weight of each car is not increasing as much as if alternative materials were used in place of plastics. This saves around 5% in emissions. For aviation, 22% of the Airbus A380 is made of plastics, helping to reduce fuel consumption by 15% over its lifecycle.

Science – and in particular chemistry – also helps us understand the most beneficial ways to deal with products which have reached the end of their useful lives. Most of the plastics that are in use are thermoplastics. After they have been collected and sorted, they can be melted again and reshaped into other articles. This enables plastics to be used in a number of different formats throughout their lifecycle. One good example is the front screens of mobiles: the different colour front-plates are made from recycled polystyrene earlier used as disposable coffee cups. This is not possible with thermoset plastics, which have a molecular structure that makes the material decompose if heated to very high temperatures.

For those plastics which can’t be recycled, LCAs demonstrate that the most effective way to protect the climate is to use them as a source of energy. Plastics are in essence solid oil, so can be used as fuel in special incinerators which efficiently convert the energy released into heat and electricity.

This chat will help students to understand some of the ways in which science can help us identify the right choices to make to protect the climate.


Comments

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