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Accuracy, Precision and Significance

The difference between accuracy-being close to the actual value-and precision-how close values are to one another-is well known.  These values can also be very misleading.  When you forecast or estimate greenhouse gas emissions, you want results that are also reliable and useful to you in designing your project.  You want significance and relevant information that will help you make decisions.  You need to rely on the tools that will give you what you need in the context of your other order-of-magnitude inputs: market, politics, financing, phasing.

In the recent book Supply Chain Network Design, authors Michael Watson, Peter Cacioppi, Jay Jayamaran and Sara Lewis have this to say:

"We often assume that more precise data is always better. However, as our lessons in significant digits taught us, we can be only as precise as our measurements allow.. data has to be good enough for the decisions we are making...problems can result when the precision and detail of the data actually get in the way of making good decisions. The analyst has to spend too much time trying to understand the data and misses the opportunity to take the much-needed action...We have seen projects in which the extremely detailed analysis of data causes the project team to miss their opportunity to impact the supply chain in a positive way.

Our goal for collecting data (for a network design model) is to define the data needed with the right level of significance to make the relevant decisions. Our ultimate responsibility is to report the results with the right level of significance for the organization to make decisions. Our goal is not to ensure that every piece of data is significant to ten decimal places. Therefore it is really a waste of time and often a risk to our project’s success when we report data with more significance than is warranted."

High forecasting precision conveys the impression of high usefulness, but be wary: what you need at the outset of a development project is to make smart strategic GHG decisions with available information. Four decimal places of precision in insignificant categories aren't necessarily going to help much.  Carbon Planner helps you stay within a range of greenhouse gas emissions for your project by giving you significant, reliable, useful forecasts-coupled with strategies for bringing it into line with local GHG goals. Then, fine-tuning and CEQA reporting can come later.

CarbonPlanner is a greenhouse gas emission forecaster that clearly shows you what's significant in your project's carbon footprint, so you can take appropriate early action.  Building and transportation emissions are always significant.  But how much time should you devote at this point to reducing the impact of your construction process or vegetation?  Sometimes it's important to do that, sometimes not so much.  To help you decide, CarbonPlanner shows you the benchmarks and gives you workable strategies for mitigation to meet local standards.  

Work with the knowledge that your GHG information is significant, relevant and useful.  Let CarbonPlanner give you actionable information now.

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