01246nas a2200205   4500008004100000022001300041245007600054210006900130260001300199300001600212490000700228520067100235653001200906653001100918653001900929100000500948700001800953700002000971856004900991       2009                        eng d  a1364032100aEnergy, economics and environmental impacts of renewable energy systems0 aEnergy economics and environmental impacts of renewable energy s  cDecember  a2716–27210 v133 aThe renewable based electricity generation technologies were assessed against a range of sustainability indicators using data obtained from the literature. These indicators are cost of electricity generation, greenhouse gas emissions and energy pay-back time. All the three parameters were found to have a very wide range for each technology. For grading different renewable energy sources a new figure of merit has been proposed, linking greenhouse gas emissions, energy pay-back time and cost of electricity generated by these renewable energy sources. It has been found out that wind and small hydro are the most sustainable source for the electricity generation.10aclimate10aenergy10asustainability1 a1 aPrakash, Ravi1 aBhat, Inder, K.  uhttp://dx.doi.org/10.1016/j.rser.2009.05.00702268nas a2200205   4500008004100000245005000041210004900091260001000140300001600150490000800166520173300174653000801907653001101915653001601926653001501942653001901957100002201976700001801998856004602016       2010                        eng d00aConsumption-based accounting of CO2 emissions0 aConsumptionbased accounting of CO2 emissions  cMarch  a5687–56920 v1073 a10.1073/pnas.0906974107 CO emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with the consumption of goods and services in each country. Consumption-based accounting of CO emissions differs from traditional, production-based inventories because of imports and exports of goods and services that, either directly or indirectly, involve CO emissions. Here, using the latest available data, we present a global consumption-based CO emissions inventory and calculations of associated consumption-based energy and carbon intensities. We find that, in 2004, 23% of global CO emissions, or 6.2 gigatonnes CO, were traded internationally, primarily as exports from China and other emerging markets to consumers in developed countries. In some wealthy countries, including Switzerland, Sweden, Austria, the United Kingdom, and France, >30% of consumption-based emissions were imported, with net imports to many Europeans of >4 tons CO per person in 2004. Net import of emissions to the United States in the same year was somewhat less: 10.8% of total consumption-based emissions and 2.4 tons CO per person. In contrast, 22.5% of the emissions produced in China in 2004 were exported, on net, to consumers elsewhere. Consumption-based accounting of CO emissions demonstrates the potential for international carbon leakage. Sharing responsibility for emissions among producers and consumers could facilitate international agreement on global climate policy that is now hindered by concerns over the regional and historical inequity of emissions.10aeeg10aenergy10afossilfuels10anorthsouth10asustainability1 aDavis, Steven, J.1 aCaldeira, Ken  uhttp://dx.doi.org/10.1073/pnas.0906974107