CO2 Emissions from Electrical Generation: 1980 to 2030

[GliderGuider]

10. When I look at the distribution I'm reminded of a PERT analysis.

It's a Project Management technique for estimating the most likely schedule for a project or task.

Regardless of the technique you use, the tendency in project estimation is to provide one number for each estimate. In other words, if you have 100 activities on your schedule, each activity would have one estimate associated with it. This is generally viewed as the “most likely” estimate.In many cases you can be more accurate by applying a simple PERT (Program Evaluation and Review Technique) model. PERT is an estimating technique that uses a weighted average of three numbers (see below) to come up with a final estimate.

• The most pessimistic (P) case when everything goes wrong
  
• The most optimistic (O) case where everything goes right
  
• The most likely (M) case given normal problems and opportunities

The resulting PERT estimate is calculated as (O + 4M + P)/6. This is called a “weighted average” since the most likely estimate is weighted four times as much as the other two values. You’ll notice that the final PERT estimate is moved slightly toward either the optimistic or pessimistic value - depending on which one is furthest from the most likely.

There are a lot of political, financial, logistical or technical assumptions that could sway an outcome in either direction. If I was an expert on what they are I'd be in the business.