> This graph is from Tim's website and illustrates the relationship λ (lambda) between the world't total accumulated wealth (C, the integral) and our ever-accelerating energy consumption rate (a, measured in 10^21 joules per year)

It's an odd choice to use global accumulated wealth rather than the global equivalent of GDP (GWP). What are the error bars on the calculation for how much the entire planet is worth in dollars?

For reference, GWP growth rate has been between 3% - 6% in the period considered by that paper. If the net world wealth growth rate was 1.82% during that period, it would suggest that depreciation effects are significant in determining that figure.