Last week the Senate Environment and Public Works Committee (EPW) held a hearing titled “Climate Change: It’s Happening Now.” That’s right folks, global warming is not going to strike “The Day After Tomorrow,” as alarmists previously predicted. It’s going to happen “Two Days Before the Day After Tomorrow” — today.
But before you sell the beach house, move to North Dakota, or join a survivalist group, you might want to read the testimonies by University of Colorado Prof. Roger Pielke, Jr., University of Alabama in Huntsville Prof. Roy Spencer, and Institute for Energy Research scholar Robert Murphy.
I’ll discuss Murphy’s testimony today and Pielke, Jr.’s later this week. (I covered the basic argument of Roy Spencer’s testimony in a previous post: Climate Models: “Epic Failure” or “Spot on Consistent” with Observed Warming?)
Murphy challenges the intellectual bona fides of the Obama administration’s May 2013 Technical Support Document (TSD) on the social cost of carbon (SCC). Climate activists increasingly invoke SCC estimates to justify the imposition of carbon taxes, fuel economy mandates, Soviet-style production quota for wind farms, fracking bans, and other interventions to rig the marketplace against reliable, affordable, fossil energy. They speak as if SCC estimates disclose an objective reality like the boiling point of water or the specific gravity of iron. In fact, SCC estimates are assumption-driven hocus-pocus or, as my colleague Myron Ebell prefers to say, “hogwash.”
SCC analysts purport to measure the damage, in monetary terms, that an incremental ton of carbon dioxide (CO2) emissions inflicts on humanity and the biosphere. As discussed previously on this blog, SCC estimates depend on assumptions about highly speculative issues such as climate sensitivity (how feedback mechanisms, positive or negative, will amplify or damp down the direct warming effect of rising greenhouse gas concentrations), climate impacts (how projected warming will affect weather patterns, ice-sheet dynamics, and eco-system services), economic impacts (how projected changes in global temperature, weather, and sea-level rise will affect agriculture, forestry, tourism, and other climate-related activities), and technological change (how adaptive capacities will develop as climate changes).
Each layer of the analysis is fraught with uncertainty and is educated guesswork at best. By adjusting the assumptions, the SCC analyst can get pretty much any result he desires.
Murphy zeroes in on the simplest part of the analysis: Which discount rates federal agencies use to estimate the present value of future projected climate change damages. [click to continue…]












