Question

Can someone please explain what Economic Input-Output Life Cycle Analysis is in the dumbest terms possible, and give me a good example with reference to materials such as steel, I am a Civil engineer student and having a difficult time understanding the concept!! Thank you!!

Answer 1

It can be a daunting task to determine the environmental impact of a product, system or service. A process-based LCA model is an initial approach to completing a life-cycle evaluation. Each itemizes inputs (materials and energy resources) and outputs (emissions and waste to the environment) for a given stage in the creation of a commodity in a process-based LCA. Therefore, for a simple product, such as a disposable paper drinking cup, one might list the materials ' paper and glue, as well as electricity or natural gas to operate the machinery to shape the input cup, and list scrap paper content, waste glue, and low-quality cups that become waste for outputs.

Nevertheless, this same process must be performed throughout the whole life cycle of the products for the cup and the use of the cup for a specific life cycle perspective. So, to make the paper, plants, and machinery to make the pulp, and forestry practices to grow and harvest the trees, one needs to identify the inputs such as pulp, water, and coloring. Similarly, inputs and outputs must be used for packing the cup for delivery to the store, the ride to the market to buy the cups, resulting from tossing the cup into the garbage and finally landfilling or incineration.

The process-based LCA approach can expand rapidly into an overwhelming number of inputs and outputs to include, even for a very simple product. Now, imagine doing the same process-based LCA for a commodity like an automobile that has more than 20,000 individual parts, or a system like generating electricity. There are two main problems with LCA approaches focused on procedures. One is defining the empirical limit. A process-based LCA's initial step is to determine what is to be included in the review and what is to be omitted and ignored.

For the example of the paper cup, one might choose to exclude the impacts of making the steel and then the processing equipment producing the cups. Establishing the boundary restricts the project's scope and therefore the time and effort taken to obtain input and output data. While it is necessary to create a feasible LCA plan, the concept of the boundary for the study automatically restricts the results and underestimates the true impacts of the life cycle.

The other major issue with LCA models based on processes is the consequences of circularity. In our modern world, producing other "things" requires a lot of the same "stuff." So, making the cup of paper requires steel machinery. Yet producing the steel machinery includes other metal-based machinery and equipment. And producing the steel needs, yes, steel machinery. Effectively, a life-cycle assessment of all materials and processes must be completed before any product or system can complete a life-cycle assessment.