104 research outputs found
Electricity portfolio innovation for energy security: the case of carbon constrained China
China’s energy sector is under pressure to achieve secure and affordable supply and a clear decarbonisation path. We examine the longitudinal trajectory of the Chinese electricity supply security and model the near future supply security based on the 12th 5 year plan. Our deterministic approach combines Shannon-Wiener, Herfindahl-Hirschman and electricity import dependence indices for supply security appraisal. We find that electricity portfolio innovation allows China to provide secure energy supply despite increasing import dependence. It is argued that long-term aggressive deployment of renewable energy will unblock China’s coal-biased technological lock-in and increase supply security in all fronts. However, reduced supply diversity in China during the 1990s will not recover until after 2020s due to the long-term coal lock-in that can threaten to hold China’s back from realising its full potential
Historical emissions of carbonaceous aerosols from biomass and fossil fuel burning for the period 1870–2000
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94787/1/gbc1172.pd
Slicing the Pie: How Big Could Carbon Dioxide Removal Be?
The current global dependence on using fossil fuels to meet energy needs continues to increase. If 2°C warming by 2050 is to be prevented, it will become important to adopt strategies that not only avoid CO2 emissions, but also allow for the direct removal of CO2 from the atmosphere, enabling the intervention of climate change. The primary direct removal methods discussed in this contribution include land management, mineral carbonation and bioenergy and direct air capture with carbon capture and reliable storage. These methods are discussed in detail and their potential for CO2 removal assessed. The global upper bound for annual CO2 removal was estimated to be 12, 10, 6, and 5 GtCO2/yr for BECCS, DACS, land management, and mineral carbonation, respectively – resulting in a cumulative value of about 33 GtCO2/yr. However, in the case of DACS, global data on the overlap of low-emission energy sources and reliable CO2 storage opportunities – set as a qualification for DAC viability – was unavailable and the potential upper bound estimate is thus considered conservative. While direct CO2 removal at the upper bounds identified in this review is insufficient to completely mitigate the projected 1,800 GtCO2 emissions projected by 2050, the cumulative impact of these methods could counteract up to ~60% of these emissions. The upper bounds on the costs associated with the direct CO2 removal methods varied from approximately 1000/tCO2 (again, these are the upper bounds for costs). In this analysis these direct CO2 removal technologies are found to be technically viable and potentially important options in preventing 2°C warming by 2050. However, caution is warranted in moving forward with implementation of CO2 removal, especially in the case of attempting to rapidly decrease atmospheric concentrations; it is recommended that the risks of scaling up too quickly be weighed against the existing risks associated with global warming.
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Anthropogenic Heat Release Into the Environment
This work is intended to systematically study an inventory of the anthropogenic heat produced. This research strives to present a better estimate of the energy generated by humans and human activities, and compare this estimate to the significant energy quantity with respect to climate change. Because the top of atmosphere (TOA) net energy flux was found to be 0.85 ± 0.15 W/m2 the planet is out of energy balance, as studied by the group from NASA in 2005. The Earth is estimated to gain 431 terawatts (TW) from this energy imbalance. This number is the significant heat quantity to consider when studying global climate change, and not the 78,300 TW, the absorbed part of the primary solar radiation reaching the Earth's surface, as commonly cited and used at present in the literature. Based on energy supplied to the boilers (in the Rankine cycle) of at least 13 TW, body energy dissipated by 7 × 109 people and their domestic animals, the value of the total world anthropogenic heat production rate is 15.26 TW or 3.5% of the energy gain by the Earth. Based on world energy consumption and the energy dissipated by 7 × 109 people and their domestic animals, the value of the total world anthropogenic heat production rate is 19.7 TW or about 5% of the energy gain by the Earth. These numbers are significantly different from 13 TW. More importantly, the figures are 3.5–5% of the net energy gained by the Earth, and hence significant. The quantity is not 0.017% of the absorbed part of the main solar radiation reaching the Earth's surface and negligible
A study of auroral zone attenuation of high frequency radio waves : progress report for the quarter July 1-September, 1956 /
"June 14, 1957."Work performed for United States Information Agency contract no.Mode of access: Internet
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