Our Fair Plan to Safeguard Earth’s Climate reduces the emission of greenhouse gases to zero over the 80-year time period 2020 to 2100. To accomplish this, humanity must reduce its carbon intensity—the amount of CO&l...Our Fair Plan to Safeguard Earth’s Climate reduces the emission of greenhouse gases to zero over the 80-year time period 2020 to 2100. To accomplish this, humanity must reduce its carbon intensity—the amount of CO<sub>2</sub> emitted per unit of energy—and its energy intensity—the amount of energy needed to generate a unit of Gross World Product. As shown in our Fair Plan 8 paper, reducing the future growth of the human population can also contribute to the reduction in greenhouse-gas emissions. Here, we explore this further. We project the historical decrease in Total Fertility Rate (TFR) across the 21<sup>st</sup> century toward its logistical asymptotic Reference value of 2.04 Births Per Woman (BPW). We then engineer the asymptotic TFR beginning in 2020 to 1.95, 1.85, 1.75, 1.65 & 1.55 BPW. We project the population across the 21<sup>st</sup> century for the Reference and engineered TFRs. We do so using the results of Basten, Lutz and Scherbov (2013) for the population evolution across the 21<sup>st</sup> century for 8 constant TFR values (=2.50, 2.25, 2.00, 1.75, 1.50, 1.25, 1.00 & 0.75 BPW). We find that purposefully engineering the asymptotic TFR can significantly contribute to achieving the reduction in greenhouse-gas emissions needed to transition to our Fair Plan to Safeguard Earth’s Climate.展开更多
With the election of Donald Trump as President of the United States of America, it appears likely that the initiation of mitigation of human-caused Global-Warming/Climate-Change will be delayed many years. Accordingly...With the election of Donald Trump as President of the United States of America, it appears likely that the initiation of mitigation of human-caused Global-Warming/Climate-Change will be delayed many years. Accordingly, here we calculate the Emission Phaseout Duration, D = YE - YS, where YS and YE are the Start and End Years of the emissions reduction, for YS = 2020, 2025 and 2030, and maximum Global Warming targets, ΔTmax = 2.0°C, 1.9°C, 1.8°C, 1.7°C, 1.6°C and 1.5°C. The 2.0°C and 1.5°C maxima are the “Hard” and “Aspirational” targets of the 2015 Paris Climate Agreement. We find that D decreases with increasing YS from 2020, and with decreasing ΔTmax. In particular, D decreases from: 1) 76 years for YS = 2020 to 53 years for YS = 2030 for ΔTmax = 2.0°C, and 2) 34 years for YS = 2020 to 7 years for YS = 2030 for ΔTmax = 1.5°C. Thus, delaying the initiation of the phaseout of greenhouse-gas emissions from 2020 to 2030 makes it more difficult to achieve ΔTmax = 2.0°C and impossible to achieve ΔTmax = 1.5°C.展开更多
针对电动垂直起降飞行器(electric Vertical Take-off and Landing,eVTOL)合乘运营场景下的动态请求匹配问题,对合乘匹配及路径规划进行研究.首先,考虑eVTOL垂直起降机场容量、eVTOL载重、电池能耗等限制,以乘客和eVTOL运营商利益最大...针对电动垂直起降飞行器(electric Vertical Take-off and Landing,eVTOL)合乘运营场景下的动态请求匹配问题,对合乘匹配及路径规划进行研究.首先,考虑eVTOL垂直起降机场容量、eVTOL载重、电池能耗等限制,以乘客和eVTOL运营商利益最大化为目标建立基于合乘公平性的动态eVTOL路径规划模型;其次,使用基本插入算法和线性插入算法对问题模型进行求解,并对比分析按照先到先服务和请求优先级将新请求与eVTOL进行匹配的两种处理方式;最后,以T市5个火车站和1个机场作为垂直机场,用其实际地理位置信息进行算例研究.研究结果表明:与基本插入算法相比,线性插入算法的计算时间缩短了60%以上,证明该算法可以有效求解模型;与按照先到先服务处理方式相比,请求优先级处理新请求时乘客的平均支付费用减少了0.87%,运营商合乘收益提升了5.86%,实现了在保障乘客和运营商利益下新请求与eVTOL的较优匹配.所构建的动态路径规划模型为eVTOL共享运营模式提供参考.展开更多
文摘Our Fair Plan to Safeguard Earth’s Climate reduces the emission of greenhouse gases to zero over the 80-year time period 2020 to 2100. To accomplish this, humanity must reduce its carbon intensity—the amount of CO<sub>2</sub> emitted per unit of energy—and its energy intensity—the amount of energy needed to generate a unit of Gross World Product. As shown in our Fair Plan 8 paper, reducing the future growth of the human population can also contribute to the reduction in greenhouse-gas emissions. Here, we explore this further. We project the historical decrease in Total Fertility Rate (TFR) across the 21<sup>st</sup> century toward its logistical asymptotic Reference value of 2.04 Births Per Woman (BPW). We then engineer the asymptotic TFR beginning in 2020 to 1.95, 1.85, 1.75, 1.65 & 1.55 BPW. We project the population across the 21<sup>st</sup> century for the Reference and engineered TFRs. We do so using the results of Basten, Lutz and Scherbov (2013) for the population evolution across the 21<sup>st</sup> century for 8 constant TFR values (=2.50, 2.25, 2.00, 1.75, 1.50, 1.25, 1.00 & 0.75 BPW). We find that purposefully engineering the asymptotic TFR can significantly contribute to achieving the reduction in greenhouse-gas emissions needed to transition to our Fair Plan to Safeguard Earth’s Climate.
文摘With the election of Donald Trump as President of the United States of America, it appears likely that the initiation of mitigation of human-caused Global-Warming/Climate-Change will be delayed many years. Accordingly, here we calculate the Emission Phaseout Duration, D = YE - YS, where YS and YE are the Start and End Years of the emissions reduction, for YS = 2020, 2025 and 2030, and maximum Global Warming targets, ΔTmax = 2.0°C, 1.9°C, 1.8°C, 1.7°C, 1.6°C and 1.5°C. The 2.0°C and 1.5°C maxima are the “Hard” and “Aspirational” targets of the 2015 Paris Climate Agreement. We find that D decreases with increasing YS from 2020, and with decreasing ΔTmax. In particular, D decreases from: 1) 76 years for YS = 2020 to 53 years for YS = 2030 for ΔTmax = 2.0°C, and 2) 34 years for YS = 2020 to 7 years for YS = 2030 for ΔTmax = 1.5°C. Thus, delaying the initiation of the phaseout of greenhouse-gas emissions from 2020 to 2030 makes it more difficult to achieve ΔTmax = 2.0°C and impossible to achieve ΔTmax = 1.5°C.
文摘针对电动垂直起降飞行器(electric Vertical Take-off and Landing,eVTOL)合乘运营场景下的动态请求匹配问题,对合乘匹配及路径规划进行研究.首先,考虑eVTOL垂直起降机场容量、eVTOL载重、电池能耗等限制,以乘客和eVTOL运营商利益最大化为目标建立基于合乘公平性的动态eVTOL路径规划模型;其次,使用基本插入算法和线性插入算法对问题模型进行求解,并对比分析按照先到先服务和请求优先级将新请求与eVTOL进行匹配的两种处理方式;最后,以T市5个火车站和1个机场作为垂直机场,用其实际地理位置信息进行算例研究.研究结果表明:与基本插入算法相比,线性插入算法的计算时间缩短了60%以上,证明该算法可以有效求解模型;与按照先到先服务处理方式相比,请求优先级处理新请求时乘客的平均支付费用减少了0.87%,运营商合乘收益提升了5.86%,实现了在保障乘客和运营商利益下新请求与eVTOL的较优匹配.所构建的动态路径规划模型为eVTOL共享运营模式提供参考.
