On 22 September 2020,within the backdrop of the COVID-19 global pandemic,China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060.This carbon-neutral goal is ge...On 22 September 2020,within the backdrop of the COVID-19 global pandemic,China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060.This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases.The planning effort is now in full swing in China,but the pathway to decarbonization is unclear.The needed transition towards non-fossil fuel energy and its impact on China and the world may be more profound than its reform and development over the past 40 years,but the challenges are enormous.Analysis of four representative scenarios shows significant differences in achieving the carbon-neutral goal,particularly the contribution of non-fossil fuel energy sources.The high target values for nuclear,wind,and bioenergy have approached their corresponding resource limitations,with solar energy being the exception,suggesting solar’s critical role.We also found that the near-term policies that allow for a gradual transition,followed by more drastic changes after 2030,can eventually reach the carbon-neutral goal and lead to less of a reduction in cumulative emissions,thus inconsistent with the IPCC 1.5°C scenario.The challenges and prospects are discussed in the historical context of China’s socio-economic reform,globalization,international collaboration,and development.展开更多
Monckton of Brenchley et al.(Sci Bull60:122–135, 2015)(hereafter called M15) use a simple energy balance model to estimate climate response. They select parameters for this model based on semantic arguments, leading ...Monckton of Brenchley et al.(Sci Bull60:122–135, 2015)(hereafter called M15) use a simple energy balance model to estimate climate response. They select parameters for this model based on semantic arguments, leading to different results from those obtained in physics-based studies. M15 did not validate their model against observations, but instead created synthetic test data based on subjective assumptions. We show that M15 systematically underestimate warming: since 1990, most years were warmer than their modelled upper limit. During 2000–2010, RMS error and bias are approximately 150 % and 350 % larger than for the CMIP5 median, using either the Berkeley Earth or Cowtan and Way surface temperature data. We show that this poor performance can be explained by a logical flaw in theparameter selection and that selected parameters contradict observational estimates. M15 also conclude that climate has a near-instantaneous response to forcing, implying no net energy imbalance for the Earth. This contributes to their low estimates of future warming and is falsified by Argo float measurements that show continued ocean heating and therefore a sustained energy imbalance. M15's estimates of climate response and future global warming are not consistent with measurements and so cannot be considered credible.展开更多
基金supported by the National Key R&D Program of China(Grant No.2017YFB0504000).
文摘On 22 September 2020,within the backdrop of the COVID-19 global pandemic,China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060.This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases.The planning effort is now in full swing in China,but the pathway to decarbonization is unclear.The needed transition towards non-fossil fuel energy and its impact on China and the world may be more profound than its reform and development over the past 40 years,but the challenges are enormous.Analysis of four representative scenarios shows significant differences in achieving the carbon-neutral goal,particularly the contribution of non-fossil fuel energy sources.The high target values for nuclear,wind,and bioenergy have approached their corresponding resource limitations,with solar energy being the exception,suggesting solar’s critical role.We also found that the near-term policies that allow for a gradual transition,followed by more drastic changes after 2030,can eventually reach the carbon-neutral goal and lead to less of a reduction in cumulative emissions,thus inconsistent with the IPCC 1.5°C scenario.The challenges and prospects are discussed in the historical context of China’s socio-economic reform,globalization,international collaboration,and development.
文摘Monckton of Brenchley et al.(Sci Bull60:122–135, 2015)(hereafter called M15) use a simple energy balance model to estimate climate response. They select parameters for this model based on semantic arguments, leading to different results from those obtained in physics-based studies. M15 did not validate their model against observations, but instead created synthetic test data based on subjective assumptions. We show that M15 systematically underestimate warming: since 1990, most years were warmer than their modelled upper limit. During 2000–2010, RMS error and bias are approximately 150 % and 350 % larger than for the CMIP5 median, using either the Berkeley Earth or Cowtan and Way surface temperature data. We show that this poor performance can be explained by a logical flaw in theparameter selection and that selected parameters contradict observational estimates. M15 also conclude that climate has a near-instantaneous response to forcing, implying no net energy imbalance for the Earth. This contributes to their low estimates of future warming and is falsified by Argo float measurements that show continued ocean heating and therefore a sustained energy imbalance. M15's estimates of climate response and future global warming are not consistent with measurements and so cannot be considered credible.
