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Future scenarios with significant anthropogenic climate change also display large increases in world production of fossil fuels, the principal CO2 emission source. Meanwhile, fossil fuel depletion has also been identified as a future challenge. This chapter reviews the connection between these two issues and concludes that limits to availability of fossil fuels will set a limit for mankind's ability to affect the climate. However, this limit is unclear as various studies have reached quite different conclusions regarding future atmospheric CO2 concentrations caused by fossil fuel limitations. It is concluded that the current set of emission scenarios used by the IPCC and others is perforated by optimistic expectations on future fossil fuel production that are improbable or even unrealistic. The current situation, where climate models largely rely on emission scenarios detached from the reality of supply and its inherent problems is problematic. In fact, it may even mislead planners and politicians into making decisions that mitigate one problem but make the other one worse. It is important to understand that the fossil energy problem and the anthropogenic climate change problem are tightly connected and need to be treated as two interwoven challenges necessitating a holistic solution.

Chinese energy consumption has been dominated by coal for decades, but this needs to change to protect the environment and mitigate anthropogenic climate change. Renewable energy development is needed to fulfil the Intended Nationally Determined Contribution (INDC) for the post-2020 period, as stated on the 2015 United Nations Climate Change Conference in Paris. This paper reviews the potential of renewable energy in China and how it could be utilised to meet the INDC goals. A business-as-usual case and eight alternative scenarios with 40% renewable electricity are explored using the EnergyPLAN model to visualise out to the year 2030. Five criteria (total cost, total capacity, excess electricity, CO2 emissions, and direct job creation) are used to assess the sustainability of the scenarios. The results indicate that renewables can meet the goal of a 20% share of non-fossil energy in primary energy and 40%-50% share of non-fossil energy in electricity power. The low nuclear-hydro power scenario is the most optimal scenario based on the used evaluation criteria. The Chinese government should implement new policies aimed at promoting integrated development of wind power and solar PV.

Chinese energy consumption has been dominated by coal for decades, but this needs to change to protect the environment and mitigate anthropogenic climate change. Renewable energy development is needed to fulfil the Intended Nationally Determined Contribution (INDC) for the post-2020 period, as stated on the 2015 United Nations Climate Change Conference in Paris. This paper reviews the potential of renewable energy in China and how it could be utilised to meet the INDC goals. A business-as-usual case and eight alternative scenarios with 40% renewable electricity are explored using the EnergyPLAN model to visualise out to the year 2030. Five criteria (total cost, total capacity, excess electricity, CO2 emissions, and direct job creation) are used to assess the sustainability of the scenarios. The results indicate that renewables can meet the goal of a 20% share of non-fossil energy in primary energy and 40%–50% share of non-fossil energy in electricity power. The low nuclear-hydro power scenario is the most optimal scenario based on the used evaluation criteria. The Chinese government should implement new policies aimed at promoting integrated development of wind power and solar PV

Xu-gang Tang,1 Ji-hang Zhang,1 Xu-bin Gao,1 Qian-ning Li,2 Jia-bei Li,1 Jie Yu1 Jun Qin,1 Lan Huang11Institute of Cardiovascular Diseases, 2Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of ChinaObjective: We aimed to observe the changes in subjective sleep quality among insomniacs and non-insomniacs after acute ascending to 3,700 m and its possible relationship with acute mountain sickness (AMS). Methods: A total of 600 adult men were recruited. Subjects' subjective sleep quality was evaluated by the Athens Insomnia Scale. AMS was assessed using the Lake Louise scoring system. Arterial oxygen saturation was measured. Results: Despite insomnia resolution in only a few subjects, the prevalence of insomnia among insomniacs remained stable at 90% after rapid ascent to 3,700 m. However, among non-insomniacs, the prevalence of insomnia sharply increased to 32.13% in the first day of altitude exposure and progressively reduced to 4.26% by the 60th day of altitude stay. Moreover, the prevalences of insomnia symptoms decreased more markedly from day 1 to day 60 at 3,700 m among non-insomniacs than among insomniacs. At 3,700 m, the prevalence of AMS among insomniacs was 79.01%, 60.49%, and 32.10% on the first, third, and seventh days, respectively, which was significantly higher than that among non-insomniacs. Multivariate regression revealed that elevated Athens Insomnia Scale scores are an independent risk factor for AMS (adjusted odds ratio 1.388, 95% confidence interval: 1.314–1.464, P<0.001), whereas high arterial oxygen saturation and long duration of altitude exposure are protective factors against AMS. Conclusion: Our results suggest that the effect of high-altitude exposure on subjective sleep quality is more marked, but disappears more quickly, among non-insomniacs than among insomniacs, whereas AMS is especially common among insomniacs. Moreover, poor subjective sleep quality is a risk factor for AMS. Keywords: Athens Insomnia Scale, arterial oxygen saturation, rapid ascent, sleep

Xu-gang Tang,1 Ji-hang Zhang,1 Jun Qin,1 Xu-bin Gao,1 Qian-ning Li,2 Jie Yu,1 Xiao-han Ding,1 Lan Huang1 1Institute of Cardiovascular Diseases, 2Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China Background: The aim of this study was to explore the relationship between age and acute mountain sickness (AMS) when subjects are exposed suddenly to high altitude.Methods: A total of 856 young adult men were recruited. Before and after acute altitude exposure, the Athens Insomnia Scale score (AISS) was used to evaluate the subjective sleep quality of subjects. AMS was assessed using the Lake Louise scoring system. Heart rate (HR) and arterial oxygen saturation (SaO2) were measured.Results: Results showed that, at 500 m, AISS and insomnia prevalence were higher in older individuals. After acute exposure to altitude, the HR, AISS, and insomnia prevalence increased sharply, and the increase in older individuals was more marked. The opposite trend was observed for SaO2. At 3,700 m, the prevalence of AMS increased with age, as did severe AMS, and AMS symptoms (except gastrointestinal symptoms). Multivariate logistic regression analysis showed that age was a risk factor for AMS (adjusted odds ratio [OR] 1.07, 95% confidence interval [CI] 1.01–1.13, P<0.05), as well as AISS (adjusted OR 1.39, 95% CI 1.28–1.51, P<0.001).Conclusion: The present study is the first to demonstrate that older age is an independent risk factor for AMS upon rapid ascent to high altitude among young adult Chinese men, and pre-existing poor subjective sleep quality may be a contributor to increased AMS prevalence in older subjects. Keywords: acute mountain sickness, age, Athens Insomnia Scale, rapid ascent, sleep

<b><i>Background:</i></b> <i>Sirtuin</i> 6 gene (SIRT6) is a longevity gene that is involved in a variety of metabolic pathways, but the relationship between SIRT6 methylation and longevity has not been clarified. <b><i>Methods:</i></b> We conducted a case-control study on 129 residents with a family history of longevity (1 of parents, themselves, or siblings aged ≥90 years) and 86 individuals without a family history of exceptional longevity to identify the association. DNA pyrosequencing was performed to analyze the methylation status of <i>SIRT6</i> promoter CpG sites. qRT-PCR and ELISA were used to estimate the <i>SIRT6</i> messenger RNA (mRNA) levels and protein content. Six CpG sites (P1–P6) were identified as methylation variable positions in the <i>SIRT6</i> promoter region. <b><i>Results:</i></b> At the P2 and P5 CpG sites, the methylation rates of the longevity group were lower than those of the control group (<i>p</i> &#x3c; 0.001 and <i>p</i> = 0.009), which might be independent determinants of longevity. The mRNA and protein levels of <i>SIRT6</i> decreased in the control group (<i>p</i> &#x3c; 0.0001 and <i>p</i> = 0.038). The mRNA level negatively correlated with the methylation rates at the P2 (<i>r</i>_s = −0.173, <i>p</i> = 0.011) and P5 sites (<i>r</i>_s = −0.207, <i>p</i> = 0.002). Furthermore, the protein content positively correlated with the methylation rate at the P5 site (<i>r</i>_s = 0.136, <i>p</i> = 0.046) but showed no significant correlation with the methylation rate at the P2 site. <b><i>Conclusion:</i></b> The low level of <i>SIRT6</i> methylation may be a potential protective factor of Chinese longevity.