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Given the extreme risk to civilization of continuing with essentially unrestrained MK-2461 fuel burning, an important question for all is what are scientifically sound, economically viable, and ethically defendable strategies to mitigate the global warming trend and manage these climate risks? Reducing fossil fuel burning by using energy-saving & emission-reduction technologies in industries & agriculture is clearly the most direct strategy to combat the ongoing change in global climate (e.g. Geng et?al., 2014, Upham et?al., 2011 and Cheah et?al., 2013). Negotiations on carbon emissions reduction have largely failed because of lack of international trust and the unwillingness of most governments to pursue anything except blind short-term self-interest. The Kyoto Protocol and subsequent emissions negotiations have been obstructed repeatedly, particularly by representatives of the US government, but also by much of the developed world which has consistently failed to acknowledge their historical contribution to climate damage (Wei et al., 2011), and in some cases continues to deny basic science in the field. In response some scientists have proposed to use geoengineering (or climate engineering) to artificially cool the planet (Royal Society, 2009). Geoengineering is the intentional large-scale manipulation of the environment, particularly manipulation that is intended to reduce undesired anthropogenic climate change (Keith, 2000). Many different types of geoengineering have been proposed (Royal Society, 2009, Royal Society, 2011 and Izrael et?al., 2009), but while some of them involve slow and virtually risk free lowering of atmospheric CO2 concentration (e.g. by afforestation), the main attraction of geoengineering lies in schemes that offer low-energy costs and short lead times for technical implementation. These geoengineering schemes would act rapidly to lower temperatures with significant decreases occurring within 1–2 years (Bala, 2009) and may be produce side effects at the same time (Moriarty and Honnery, 2010). Prolonged geoengineering would also curb sea level rise, which is arguably the largest climate risk since 150 million people live within 1 m of high tide globally, and coastal city growth is expected to surpass global average growth in the 21st century. Moderate geoengineering options can constrain sea-level rise to about 50 cm above 2000 levels in the RCP3PD and RCP4.5 future climate scenarios1, but only aggressive geoengineering can similarly constrain the RCP8.5 future climate scenario (Moore et al., 2010). Importantly once started, geoengineering must be maintained for a very long period. Otherwise, when it is terminated, climate reverts rapidly to maintain a global energy balance. If greenhouse gas concentrations continue to rise, then unprecedented and highly damaging rapid climate change will then occur (the so-called “termination shock”, Jones et?al., 2013a and Jones et?al., 2013b).