MAC Curves VS Sustainability Tools​
Reducing Environmental Impacts in Civil Engineering
The Marginal Abatement Cost Curve (MACC)
The MAC curve is an economic tool that is used to consider a set of options in order to reduce the carbon footprint of a product or process. This is done by interpretation of complex numerical data by experts to develop a curve for visual reference.
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The curve shows the cost for various abatement measures which allows comparisons to be made. These comparisons assist policy makers and stakeholders in making decisions with regards to reducing carbon emissions.
​The MAC Curve was developed in the 1970s and was initially used to try and reduce crude oil and electricity consumption. It was only in the 1990s that the MAC curve was edited to tackle problems relating to carbon emissions. Today the most well known and widely used MAC curve is that developed by Mckinsey and company.
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The Mckinsey MAC curves are based on an assessment of different abatement measures. A panel of experts analyse numerical data to provide a rating for the abatement potential of each mitigation measure. These are then rated in order from cheapest to most expensive which allows for an easy of comparison of the various measures.
This Mckinsey MAC shows the global GHG abatement costs. This is calculated as the additional operating cost minus the potential savings costs divided by the amount of emissions avoided by that abatement measure. Which means that a negative cost can be achieved if the potential savings are larger than the operating costs.
Here is another example of the Mckinsey MAC used to determine the India's carbon dioxide abatement costs for 2030.
This Mckinsey MAC shows the global GHG abatement costs. This is calculated as the additional operating cost minus the potential savings costs divided by the amount of emissions avoided by that abatement measure. Which means that a negative cost can be achieved if the potential savings are larger than the operating costs.
Shortcomings of the MAC Curve
The MAC curve is a very complex tool and therefore has many disadvantages. The disadvantages are usually based on general MAC curve or its construction. The complexity issues lead to certain caveats or cautions to be looked over. This usually results in excessive confidence being placed in the curves. The assumptions behind the construction of the curve need to be clearly laid out for the MAC curve to be most efficient.
This means the MAC curve cannot be used solely to rank abatement policies. The simple graphical representation of the MAC curve does help in decision making but can only be used as a rough guide. However, if the caveats mentioned in this report have been taken into considerations and the assumptions made transparent then the curves should be able to yield more accurate results with fewer aspects being looked over.
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The University College London (UCL) Energy Institute have provided us with a detailed description of the shortcomings of the MAC Curve. To view this document click on the button below.
