Decarbonization in Our Future?
At a briefing February 7 sponsored by the Cooler Heads Coalition, Jesse Ausubel, a researcher at the Rockefeller University, laid out a framework for thinking about global warming issues. There are several points at which the issue is being debated. There are the issues of energy use, emissions, and concentrations; climate sensitivity, or how much the climate may warm due to increases in greenhouse gas concentrations; the potential impacts on ecosystems and people; and so on.
Ausubel argued that many of these issues are essentially unknowable. Climate sensitivity, for example, has been estimated at different extremes. The aggregate results from peer-reviewed scientific studies show a normal distribution of climate sensitivities. Some suggest that a doubling atmospheric carbon dioxide concentration will warm the climate by about 4.5 degrees Celsius. Others show low climate sensitivity, which would lead to a warming of 1.5 degrees C. Still others fall somewhere in the middle. As Ausubel stated, “The pile of papers keeps getting larger, but the shape of the pile never changes.”
The real debate, according to Ausubel, lies in the trends in energy use. This is one variable that is known, and as Ausubel has discovered, the world has experienced a sustained long-running reduction in carbon intensity in its energy use. Wood, still a major source of fuel in less developed countries, has a hydrogen-to-carbon ratio of 1 to 10. Coals H:C ratio is 1 to 2, oil 2 to 1, and methane or natural gas about 4 to 1.
The world has been steadily decarbonizing for the last 150 years, from wood to coal to oil, and now to methane. Ausubel argues, somewhat controversially, that total decarbonization is in our future and that the economy will run on hydrogen, powered by nuclear power. That may well be the case.
One of the major implications of decarbonization is that energy policy may be irrelevant. As Ausubel has noted elsewhere, “Neither Queen Victoria nor Abraham Lincoln decreed a policy of decarbonization. Yet, the system pursued it.” Decarbonization and our path to the hydrogen economy will happen regardless of government decrees or federal research money.
Ausubel also takes to task the UN Intergovernmental Panel on Climate Change for its assumptions on energy use. When Ausubel extrapolated decarbonization trends out to the year 2100 and compared it to the IPCCs 1990 “business as usual” (BAU) scenario he found that they bore little resemblance to one another.
The IPCCs BAU scenario was a flat line, which assumes technical stagnation or what Ausubel dubs the Breschnev Scenario. But properly understood, BAU is a technologically dynamic and progressive scenario that will eliminate CO2 by 2100. The IPCCs 2001 Third Assessment Report uses 40 scenarios which show decarbonization and carbonization going in all different directions with no probabilities attached.
IPCCs Economic Assumptions Assailed
The Economist (February 13, 2003) has published an article featuring criticisms leveled at the UNs Intergovernmental Panel on Climate Change for the economic assumptions it used to come up with its temperature projections.
“In recent months,” according to the Economist, “two distinguished commentators Ian Castles of the National Center for Development Studies at Australian National University, formerly the head of Australias national office of statistics; and David Henderson of the Westminster Business School, formerly chief economist of the OECD have put together a critique of the panels Special Report of Emissions Scenarios (SRES).”
The major points of contention are the assumptions about the gap between rich and poor countries and the speed at which the gap will be closed. The SRES based its projections of future output on GDP estimates that were converted into a common measure using market exchange rates. Because prices tend to be much lower in poor countries, this method significantly overstates the gap in average incomes between rich and poor countries.
The IPCC assumed that the rich countries will continue to grow and that in most of the 40 SRES scenarios the poor countries will close the income gap by the year 2100. The combination of the overstated gap and the assumption of convergence lead to vastly overestimated emissions scenarios.
Even more startling are projections that show the per capita incomes of those living in South Africa, Algeria, Libya, Turkey and North Korea overtaking the per capita incomes of Americans by 2100 by a wide margin. There are several other serious errors in the SRES scenarios as well. Castles and Hendersons analysis will be published in a forthcoming issue of Energy and Environment.
Renewable Energy in Decline
The Energy Information Administration has released a report showing that the consumption of renewable energy fell significantly in 2001. Much of the decline was attributed to a drought which curtailed the generation of hydroelectric power by 23 percent. But the report also noted that the equipment used to produce solar power is being retired faster than new equipment is being installed.
Much of that equipment was installed in the 1970s and 1980s when there were plentiful subsidies available for distributed solar power. But now the equipment is getting old and wearing out, and the subsidies are no longer available to replace it.
Even though the use of solar collectors and wind turbines has increased over the last few years, overall consumption of renewable energy fell by 12 percent in 2001, the lowest point in over 12 years. In all, renewables only account for 6 percent of the nations energy consumption (Energy Central, February 18, 2003).