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Young People's Burden: Requirement of Negative CO2 Emissions
Abstract. The rapid rise of global temperature that began about 1975 continues at a mean rate of about 0.18 °C/decade, with the current annual temperature exceeding +1.25 °C relative to 1880–1920. Global temperature has just reached a level similar to the mean level in the prior interglacial (Eemian) period, when sea level was several meters higher than today, and, if it long remains at this level, slow amplifying feedbacks will lead to greater climate change and consequences. The growth rate of climate forcing due to human-caused greenhouse gases (GHGs) increased over 20 % in the past decade mainly due to resurging growth of atmospheric CH4, thus making it increasingly difficult to achieve targets such as limiting global warming to 1.5 °C or reducing atmospheric CO2 below 350 ppm. Such targets now require "negative emissions", i.e., extraction of CO2 from the atmosphere. If rapid phasedown of fossil fuel emissions begins soon, most of the necessary CO2 extraction can take place via improved agricultural and forestry practices, including reforestation and steps to improve soil fertility and increase its carbon content. In this case, the magnitude and duration of global temperature excursion above the natural range of the current interglacial (Holocene) could be limited and irreversible climate impacts could be minimized. In contrast, continued high fossil fuel emissions by the current generation would place a burden on young people to undertake massive technological CO2 extraction, if they are to limit climate change. Proposed methods of extraction such as bioenergy with carbon capture and storage (BECCS) or air capture of CO2 imply minimal estimated costs of 104–570 trillion dollars this century, with large risks and uncertain feasibility. Continued high fossil fuel emissions unarguably sentences young people to either a massive, possibly implausible cleanup or growing deleterious climate impacts or both, scenarios that should provide both incentive and obligation for governments to alter energy policies ...
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Young People's Burden: Requirement of Negative CO2 Emissions
Abstract. The rapid rise of global temperature that began about 1975 continues at a mean rate of about 0.18 °C/decade, with the current annual temperature exceeding +1.25 °C relative to 1880–1920. Global temperature has just reached a level similar to the mean level in the prior interglacial (Eemian) period, when sea level was several meters higher than today, and, if it long remains at this level, slow amplifying feedbacks will lead to greater climate change and consequences. The growth rate of climate forcing due to human-caused greenhouse gases (GHGs) increased over 20 % in the past decade mainly due to resurging growth of atmospheric CH4, thus making it increasingly difficult to achieve targets such as limiting global warming to 1.5 °C or reducing atmospheric CO2 below 350 ppm. Such targets now require "negative emissions", i.e., extraction of CO2 from the atmosphere. If rapid phasedown of fossil fuel emissions begins soon, most of the necessary CO2 extraction can take place via improved agricultural and forestry practices, including reforestation and steps to improve soil fertility and increase its carbon content. In this case, the magnitude and duration of global temperature excursion above the natural range of the current interglacial (Holocene) could be limited and irreversible climate impacts could be minimized. In contrast, continued high fossil fuel emissions by the current generation would place a burden on young people to undertake massive technological CO2 extraction, if they are to limit climate change. Proposed methods of extraction such as bioenergy with carbon capture and storage (BECCS) or air capture of CO2 imply minimal estimated costs of 104–570 trillion dollars this century, with large risks and uncertain feasibility. Continued high fossil fuel emissions unarguably sentences young people to either a massive, possibly implausible cleanup or growing deleterious climate impacts or both, scenarios that should provide both incentive and obligation for governments to alter energy policies without further delay.
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One thousand plant transcriptomes and the phylogenomics of green plants ; Nature
Green plants (Viridiplantae) include around 450,000-500,000 species(1,2) of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life. ; Alberta Ministry of Advanced Education; Alberta Innovates AITF/iCORE Strategic Chair [RES0010334]; Musea Ventures; National Key Research and Development Program of China [2016YFE0122000]; Ministry of Science and Technology of the People's Republic of ChinaMinistry of Science and Technology, China [2015BAD04B01/2015BAD04B03]; State Key Laboratory of Agricultural Genomics [2011DQ782025]; Guangdong Provincial Key Laboratory of core collection of crop genetic resources research and application [2011A091000047]; Shenzhen Municipal Government of China [CXZZ20140421112021913/JCYJ20150529150409546/JCYJ20150529150505656]; National Science FoundationNational Science Foundation (NSF) [DBI-1265383, IOS 0922742, IOS-1339156, DEB 0830009, EF-0629817, EF-1550838, DEB 0733029, DBI 1062335, 1461364]; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [1R01DA025197]; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [Qu 141/5-1, Qu 141/6-1, GR 3526/7-1, GR 3526/8-1]; Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of Canada ; The 1KP initiative was funded by the Alberta Ministry of Advanced Education and Alberta Innovates AITF/iCORE Strategic Chair (RES0010334) to G.K.-S.W., Musea Ventures, The National Key Research and Development Program of China (2016YFE0122000), The Ministry of Science and Technology of the People's Republic of China (2015BAD04B01/2015BAD04B03), the State Key Laboratory of Agricultural Genomics (2011DQ782025) and the Guangdong Provincial Key Laboratory of core collection of crop genetic resources research and application (2011A091000047). Sequencing activities at BGI were also supported by the Shenzhen Municipal Government of China (CXZZ20140421112021913/JCYJ20150529150409546/JCYJ20150529150505656). Computation support was provided by the China National GeneBank (CNGB), the Texas Advanced Computing Center (TACC), WestGrid and Compute Canada; considerable support, including personnel, computational resources and data hosting, was also provided by the iPlant Collaborative (CyVerse) funded by the National Science Foundation (DBI-1265383), National Science Foundation grants IOS 0922742 (to C.W.d., P.S.S., D.E.S. and J.H.L.-M.), IOS-1339156 (to M.S.B.), DEB 0830009 (to J.H.L.-M., C.W.d., S.W.G. and D.W.S.), EF-0629817 (to S.W.G. and D.W.S.), EF-1550838 (to M.S.B.), DEB 0733029 (to T.W. and J.H.L.-M.), and DBI 1062335 and 1461364 (to T.W.), a National Institutes of Health Grant 1R01DA025197 (to T.M.K., C.W.d. and J.H.L.-M.), Deutsche Forschungsgemeinschaft grants Qu 141/5-1, Qu 141/6-1, GR 3526/7-1, GR 3526/8-1 (to M.Q. and I.G.) and a Natural Sciences and Engineering Research Council of Canada Discovery grant (to S.W.G.). We thank all national, state, provincial and regional resource management authorities, including those of province Nord and province Sud of New Caledonia, for permitting collections of material for this research. ; Public domain authored by a U.S. government employee
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