With the Kyoto Protocol proving to be a difficult first step to slowing the rate of growth in emissions and with slow progress on moving to second and third steps that would actually start to reduce emissions, Crutzen (2006) argues that it may be time to think much more seriously about geoengineering the Earth’s climate. In addition to undertaking geoengineering to avoid the “dangerous anthropogenic interference with the climate system,” which the international community of nations agreed in 1992 was their objective in the UN Framework Convention on Climate Change, Crutzen proposes to offset the warming influence of removing the loading of tropospheric aerosols so as to alleviate their deleterious health effects, which is an interesting new aspect meriting consideration. In addition to the many scientific, legal, ethical, and societal issues that he raises with respect to undertaking such efforts, this note offers a few additional thoughts and comments.
Geoengineering: Worthy of Cautious Evaluation?
If the increasing concentrations of greenhouse gases due to human activities are indeed causing inadvertent change in the climate, then can we not counter these influences by advertent changes of some type, deliberately geoengineering the climate to ensure optimal conditions? This is a question that was first considered several decades ago, soon after acceptance of indications that it was indeed likely that human activities could affect the global climate (e.g., Marchetti, 1975; NAS, 1992). Scientific evidence now clearly indicates that human activities have initiated significant climatic change and that much greater change lies ahead (IPCC, 2001ª), that the impacts of these changes will cause significant consequences for the environment and society (IPCC, 2001b), and that switching the global energy system away from its heavy dependence on fossil fuels is likely to require more than a century (IPCC, 2001c).