Monday, July 13, 2009

The Core Narrative of Climate Change – 5

Last week’s focus was on whether can provide enough clean energy of the right kind given the growth projections for the Developing World. The IPCC sidesteps this issue by providing a number of scenarios for the rest of this century. The so-called A1 family assume population growth slows but growth is high. That is then combined with a number of associated energy assumptions – coal and oil (A1F), renewable (A1T) and a “balanced” portfolio (A1B). A1B produces enough greenhouse gasses to push all the way to 650 ppm and a 3.5 (degrees Celsius) temperature rise by the end of the century unlike A1T which keeps things in bounds at 550 ppm and 3 degrees. So fine, let’s just plan on doing A1T whoever ends up paying for it. But the problem is that A1T is a thought experiment! It is a hypothetical scenario that assumes the technology is available to provide clean energy in the right form to (literally) fuel the assumed rate of economic growth. Absent the scenario being real, the choice becomes A1 versus a low growth family of scenarios (the B family). The contrast now becomes striking when you ask how much economic growth would the Developing World have to sacrifice. Here are the IPCC figures for projected World gnp: A1B: $528.5 trillion, B1: $334 trillion.

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