Geoengineering: Encouraging Research and Overseeing Implementation

GEOENGINEERING: ENCOURAGING RESEARCH AND OVERSEEING IMPLEMENTATION An Editorial Comment Ideas on how to engineer Earth’s climate, or to modify the environment on large scales to counter human impacts, do not enjoy broad support from scientists. Ref- ereed publications that deal with such ideas are not numerous nor are they cited widely. Paul Crutzen (2006) analyzes the idea of intentionally injecting sulfur into the stratosphere, to enhance the albedo of Earth, so as to slow the warming of the planet due to greenhouse gases. He notes that such an intervention might become necessary unless the world becomes more successful in limiting greenhouse gas emissions and/or if global warming should proceed faster than currently antici- pated partly due to cleaning the lower atmosphere of sulfur pollution (Andreae et al., 2005; Charlson et al., 1991). I am aware that various individuals have opposed the publication of Crutzen’s paper, even after peer review and revisions, for various and sincere reasons that are not wholly scientific. Here, I write in support of his call for research on geo- engineering and propose a framework for future progress in which supporting and opposing viewpoints can be heard and incorporated. I also propose that research on geoengineering be considered separately from actual implementation, and I suggest a path in that direction. 1. Geoengineering – Past Ideas and Their Results Schelling (1996) has noted that while “geoengineering” is not fully defined, that “it seems to imply something global, intentional and unnatural”. Thus, not all human- caused changes to Earth’s surface, biota and flows of minerals and water would qualify. For example, Vitousek et al. (1986) and Pauly and Christensen (1995) have estimated that humans are using or diverting significant fractions of primary productivity on land and at sea, respectively, and Postel et al. (1995) have shown that humans are using significant fractions of the fresh water available globally from evapotranspiration and runoff, partly through damming of rivers to convert energy of falling water to electricity and for water management. Similarly, large changes to Earth’s surface have occurred due to clearing of forests and grassland for agriculture and pastures, and Brewer (1997) has estimated that adding CO 2 to ocean waters has measurably decreased carbonate ions, increased bicarbonate, lowered pH (see also, SCOR, 2004) and increased oceanic volume. Brewer also noted that the accumulated total production of water from combustion of fossil fuels exceeds the volume of one of the Great Lakes (Erie). Other similar indicators of disturbance Climatic Change (2006) 77: 221–226 DOI: 10.1007/s10584-006-9102-x c Springer 2006