The recognition that human activity is transforming the planet, both inintended and dramatically unintended ways, has led to the development of anew field of research—sustainability science. Widely discussed essays (e.g.,Clarke, 2002; Kates et al., 2001; Kennedy, 2003; McMichael et al., 2003;Swart et al., 2002), special issues of premier journals (NAS, 2003), and exten-sive websites (FSTS, 2005) are now devoted to defining sustainability andidentifying useful modes and topics for research. Building on this foundation,we now have a tremendous opportunity to advance a new global scientificresearch paradigm—the generation and implementation of sustainability sci-ence. One important lesson emerges very clearly from this body of work—only by posing the question of sustainability explicitly and, where necessary,repairing the damage humans have caused to the biosphere, can we begin tounderstand how humans can prosper without degrading the planet.In a seminal treatise on science policy, Vannevar Bush (1945) wrote that,“applied research invariably drives out pure [research],” to the detriment, inhis view, of the national capacity for innovation. The subsequent separationArne Jacobson and Daniel M. KammenScience and Engineering ResearchThat Values the PlanetEcological stewardship will be the guiding scientificprinciple for new avenues of inquiry.Arne Jacobson is an assistant professor in the Environmental Resources Engineering Department and a research sci-entist at the Schatz Energy Research Center, Humboldt State University. Daniel M. Kammen is the Class of 1935Distinguished Professor of Energy in the Energy and Resources Group, Goldman School of Public Policy, and Depart-ment of Nuclear Engineering at the University of California, Berkeley. He is also founding director of the Renew-able and Appropriate Energy Laboratory and co-director of the Berkeley Institute of the Environment.Arne JacobsonDaniel M. KammenTheBRIDGEof basic and applied research shaped the evolution ofscience and engineering research for decades and was apoint of departure for E.F. Schumacher (1973) and the“appropriate technology” movement, a precursor of sus-tainability science that involved identifying importantbut neglected issues for scientific study. This approach,dubbed “mundane science,” (Kammen and Dove,1997), involves projects that combine pragmatic andgoal-oriented applied research with potential advancesin basic science (Stokes, 1997). The growing recogni-tion of the value of supporting interdisciplinary researchand the emergence of sustainability science are contin-uations of the intellectual evolution of the interactionbetween science and society.The scientific recognition of the reality of globalenvironmental change (Hansen et al., 2005), the polit-ical awareness of the need to act now to address green-house gas emissions (Kennedy, 2005), and theincreasing disparities between the lives of the poor andthe wealthy provide an opportunity for galvanizingglobal action to place sustainability science at the fore-front of educational, research, and career-developmentagendas. The next step toward putting sustainable sci-ence into action is recognizing that, with ecologicalstewardship as a guiding scientific principle, entirelynew avenues of inquiry are possible.At this moment in history, this message has thepotential to transform research careers and make sus-tainability a theme that researchers, public officials, andcivil society can all embrace. The World Conferenceon Physics and Sustainable Development, held in Dur-ban, South Africa, in October and November 2005, pro-vided a forum for showcasing opportunities for theco-evolution of basic research and social advances(SAIP, 2005).Currently attention, debate, and a trans-Atlanticdivision are focused on how to provide meaningful,long-term aid and assistance to Africa. To highlight apotential solution, we present two cases of sustainablescience, engineering, and action in developing nationsthat advance both science and sustainable human andecological communities.The Energy-Health-Ecology NexusHousehold use of solid fuels is one of the leadingcauses of death and disease in developing countriesthroughout the world—particularly among womenand children (Smith et al., 2004). Over the pastdecade, a series of studieshas been conducted of pro-grams to design and dis-seminate more efficient,safer household stoves andto develop and implementsustainable forestry andfuel (often charcoal) pro-duction practices in Africa.As Figure 1 shows, com-bined attention to bothstove and forestry programscan lead to dramatic simul-taneous improvements inhuman health, ecologicalsustainability, and localeconomic development(Kammen, 1995).The Kenya study showedthat transitions from woodand dung fuels burned insimple stoves to charcoalburned in improved stovesreduced the frequency ofacute respiratory infections120.15US EPA standardProbability ofrespiratorysymptoms00.050.12,0000 4,000 6,000 8,000Average daily particulate exposure (µg/m )3ARICharcoalCeramic Wood Stoves 3-Stone Fire ALR IFIGURE 1 The exposure-response graph from a six year, 500 person, exposure and stove intervention study in Kenya. The ver-tical axis shows the percentage of time subjects participating in biweekly health examinations exhibited ARI or acute lower respi-ratory illness (ALRI) symptoms. The EPA particulate exposure standard of 200 µg/m3for PM10(particles with diameters of lessthan 10 microns) is indicated by the dotted vertical line, which forms a lower bound for the exposure range observed in the Kenyaproject. The stove and fuel combinations indicate exposure ranges. Adapted from Ezzati and Kammen, 2001.13WINTER 2005(ARI) by a factor of two.This is a tremendousimpact on ARI, the mostcommon illnesses reportedin medi-cal exams in sub-Saharan Africa. Compara-tively simple materials anddesign modifications tohousehold stoves are nowknown not only to improveenergy efficiency, but alsoto reduce particulate andgreenhouse gas emissions(Bailis et al., 2005).These benefits can beachieved at exceptionallylow cost, just a few dollarsper life saved, and have theadded benefit of mitigatingatmospheric carbon, at justa few dollars per ton of car-bon (Ezzati and Kammen, 2002). By contrast, carbontoday trades for roughly $30/ton on the