ALBERT

Description: Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martinez-Boti, M A -- Foster, G L -- Chalk, T B -- Rohling, E J -- Sexton, P F -- Lunt, D J -- Pancost, R D -- Badger, M P S -- Schmidt, D N -- England -- Nature. 2015 Feb 5;518(7537):49-54. doi: 10.1038/nature14145.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, UK. ; 1] Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, UK [2] Research School of Earth Sciences, The Australian National University, Canberra, Australian Capital Territory 2601, Australia. ; Centre for Earth, Planetary, Space and Astronomical Research, The Open University, Milton Keynes, MK7 6AA, UK. ; 1] School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK [2] The Cabot Institute, University of Bristol, Bristol BS8 1UJ, UK. ; 1] The Cabot Institute, University of Bristol, Bristol BS8 1UJ, UK [2] Organic Geochemistry Unit, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK. ; 1] The Cabot Institute, University of Bristol, Bristol BS8 1UJ, UK [2] School of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol, BS8 1RJ, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25652996" target="_blank"〉PubMed〈/a〉

Description: Atmospheric CO2 fluctuations over glacial-interglacial cycles remain a major challenge to our understanding of the carbon cycle and the climate system. Leading hypotheses put forward to explain glacial-interglacial atmospheric CO2 variations invoke changes in deep-ocean carbon storage, probably modulated by processes in the Southern Ocean, where much of the deep ocean is ventilated. A central aspect of such models is that, during deglaciations, an isolated glacial deep-ocean carbon reservoir is reconnected with the atmosphere, driving the atmospheric CO2 rise observed in ice-core records. However, direct documentation of changes in surface ocean carbon content and the associated transfer of carbon to the atmosphere during deglaciations has been hindered by the lack of proxy reconstructions that unambiguously reflect the oceanic carbonate system. Radiocarbon activity tracks changes in ocean ventilation, but not in ocean carbon content, whereas proxies that record increased deglacial upwelling do not constrain the proportion of upwelled carbon that is degassed relative to that which is taken up by the biological pump. Here we apply the boron isotope pH proxy in planktic foraminifera to two sediment cores from the sub-Antarctic Atlantic and the eastern equatorial Pacific as a more direct tracer of oceanic CO2 outgassing. We show that surface waters at both locations, which partly derive from deep water upwelled in the Southern Ocean, became a significant source of carbon to the atmosphere during the last deglaciation, when the concentration of atmospheric CO2 was increasing. This oceanic CO2 outgassing supports the view that the ventilation of a deep-ocean carbon reservoir in the Southern Ocean had a key role in the deglacial CO2 rise, although our results allow for the possibility that processes operating in other regions may also have been important for the glacial-interglacial ocean-atmosphere exchange of carbon.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martinez-Boti, M A -- Marino, G -- Foster, G L -- Ziveri, P -- Henehan, M J -- Rae, J W B -- Mortyn, P G -- Vance, D -- England -- Nature. 2015 Feb 12;518(7538):219-22. doi: 10.1038/nature14155.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, Southampton SO14 3ZH, UK. ; 1] Institute of Environmental Science and Technology (ICTA), Universitat Autonoma de Barcelona, Bellaterra, Catalonia, 08193, Spain [2] Research School of Earth Sciences, The Australian National University, Canberra, Australian Capital Territory 2601, Australia. ; 1] Institute of Environmental Science and Technology (ICTA), Universitat Autonoma de Barcelona, Bellaterra, Catalonia, 08193, Spain [2] Institucio Catalana de Recerca i Estudis Avancats, ICREA, Barcelona, Catalonia, 08010, Spain [3] Earth and Climate Cluster, Department of Earth Sciences, Faculty of Earth and Life Sciences, VU Universiteit Amsterdam, 1081HV Amsterdam, The Netherlands. ; 1] Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton Waterfront Campus, Southampton SO14 3ZH, UK [2] Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA. ; 1] Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA [2] Department of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 9AL, UK. ; 1] Institute of Environmental Science and Technology (ICTA), Universitat Autonoma de Barcelona, Bellaterra, Catalonia, 08193, Spain [2] Department of Geography, Universitat Autonoma de Barcelona, Bellaterra, Catalonia, 08193, Spain. ; Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zurich, NW D81.4, Zurich 8092, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25673416" target="_blank"〉PubMed〈/a〉

Description: Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brienen, R J W -- Phillips, O L -- Feldpausch, T R -- Gloor, E -- Baker, T R -- Lloyd, J -- Lopez-Gonzalez, G -- Monteagudo-Mendoza, A -- Malhi, Y -- Lewis, S L -- Vasquez Martinez, R -- Alexiades, M -- Alvarez Davila, E -- Alvarez-Loayza, P -- Andrade, A -- Aragao, L E O C -- Araujo-Murakami, A -- Arets, E J M M -- Arroyo, L -- Aymard C, G A -- Banki, O S -- Baraloto, C -- Barroso, J -- Bonal, D -- Boot, R G A -- Camargo, J L C -- Castilho, C V -- Chama, V -- Chao, K J -- Chave, J -- Comiskey, J A -- Cornejo Valverde, F -- da Costa, L -- de Oliveira, E A -- Di Fiore, A -- Erwin, T L -- Fauset, S -- Forsthofer, M -- Galbraith, D R -- Grahame, E S -- Groot, N -- Herault, B -- Higuchi, N -- Honorio Coronado, E N -- Keeling, H -- Killeen, T J -- Laurance, W F -- Laurance, S -- Licona, J -- Magnussen, W E -- Marimon, B S -- Marimon-Junior, B H -- Mendoza, C -- Neill, D A -- Nogueira, E M -- Nunez, P -- Pallqui Camacho, N C -- Parada, A -- Pardo-Molina, G -- Peacock, J -- Pena-Claros, M -- Pickavance, G C -- Pitman, N C A -- Poorter, L -- Prieto, A -- Quesada, C A -- Ramirez, F -- Ramirez-Angulo, H -- Restrepo, Z -- Roopsind, A -- Rudas, A -- Salomao, R P -- Schwarz, M -- Silva, N -- Silva-Espejo, J E -- Silveira, M -- Stropp, J -- Talbot, J -- ter Steege, H -- Teran-Aguilar, J -- Terborgh, J -- Thomas-Caesar, R -- Toledo, M -- Torello-Raventos, M -- Umetsu, R K -- van der Heijden, G M F -- van der Hout, P -- Guimaraes Vieira, I C -- Vieira, S A -- Vilanova, E -- Vos, V A -- Zagt, R J -- England -- Nature. 2015 Mar 19;519(7543):344-8. doi: 10.1038/nature14283.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Geography, University of Leeds, Leeds LS2 9JT, UK. ; 1] School of Geography, University of Leeds, Leeds LS2 9JT, UK. [2] Geography, College of Life and Environmental Sciences, University of Exeter, Rennes Drive, Exeter EX4 4RJ, UK. ; 1] Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, UK. [2] School of Marine and Tropical Biology, James Cook University, Cairns, 4870 Queenland, Australia. ; Jardin Botanico de Missouri, Prolongacion Bolognesi Mz.e, Lote 6, Oxapampa, Pasco, Peru. ; Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford OX1 3QK, UK. ; 1] School of Geography, University of Leeds, Leeds LS2 9JT, UK. [2] Department of Geography, University College London, Pearson Building, Gower Street, London WC1E 6BT, UK. ; School of Anthropology and Conservation, Marlowe Building, University of Kent, Canterbury CT1 3EH, UK. ; Servicios Ecosistemicos y Cambio Climatico, Jardin Botanico de Medellin, Calle 73 no. 51 D-14, C.P. 050010, Medellin, Colombia. ; Center for Tropical Conservation, Duke University, Box 90381, Durham, North Carolina 27708, USA. ; Biological Dynamics of Forest Fragment Project (INPA &STRI), C.P. 478, Manaus AM 69011-970, Brazil. ; 1] Geography, College of Life and Environmental Sciences, University of Exeter, Rennes Drive, Exeter EX4 4RJ, UK. [2] National Institute for Space Research (INPE), Av. Dos Astronautas, 1758, Sao Jose dos Campos, Sao Paulo 12227-010, Brazil. ; Museo de Historia Natural Noel Kempff Mercado, Universidad Autonoma Gabriel Rene Moreno, Casilla 2489, Av. Irala 565, Santa Cruz, Bolivia. ; Alterra, Wageningen University and Research Centre, PO Box 47, 6700 AA Wageningen, The Netherlands. ; UNELLEZ-Guanare, Programa de Ciencias del Agro y el Mar, Herbario Universitario (PORT), Mesa de Cavacas, Estado Portuguesa, 3350 Venezuela. ; Biodiversiteit en Ecosysteem Dynamica, University of Amsterdam, Postbus 94248, 1090 GE Amsterdam, The Netherlands. ; 1] Institut National de la Recherche Agronomique, UMR EcoFoG, Campus Agronomique, 97310 Kourou, French Guiana. [2] International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, Florida 33199, USA. ; Universidade Federal do Acre, Campus de Cruzeiro do Sul, Rio Branco, Brazil. ; INRA, UMR 1137 ''Ecologie et Ecophysiologie Forestiere'' 54280 Champenoux, France. ; Embrapa Roraima, Caixa Postal 133, Boa Vista, RR, CEP 69301-970, Brazil. ; Universidad Nacional San Antonio Abad del Cusco, Av. de la Cultura N degrees 733, Cusco, Peru. ; 1] School of Geography, University of Leeds, Leeds LS2 9JT, UK. [2] International Master Program of Agriculture, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung 40227, Taiwan. ; Universite Paul Sabatier CNRS, UMR 5174 Evolution et Diversite Biologique, Batiment 4R1, 31062 Toulouse, France. ; Northeast Region Inventory and Monitoring Program, National Park Service, 120 Chatham Lane, Fredericksburg, Virginia 22405, USA. ; Andes to Amazon Biodiversity Program, Puerto Maldonado, Madre de Dios, Peru. ; Universidade Federal do Para, Centro de Geociencias, Belem, CEP 66017-970 Para, Brazil. ; Universidade do Estado de Mato Grosso, Campus de Nova Xavantina, Caixa Postal 08, CEP 78.690-000, Nova Xavantina MT, Brazil. ; Department of Anthropology, University of Texas at Austin, SAC Room 5.150, 2201 Speedway Stop C3200, Austin, Texas 78712, USA. ; Department of Entomology, Smithsonian Institution, PO Box 37012, MRC 187, Washington DC 20013-7012, USA. ; Cirad, UMR Ecologie des Forets de Guyane, Campus Agronomique, 97310 Kourou, French Guiana. ; 1] School of Geography, University of Leeds, Leeds LS2 9JT, UK. [2] Instituto de Investigaciones de la Amazonia Peruana, Av. A. Jose Quinones km 2.5, Iquitos, Peru. ; World Wildlife Fund, 1250 24th Street NW, Washington DC 20037, USA. ; Centre for Tropical Environmental and Sustainability Science (TESS) and School of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia. ; Instituto Boliviano de Investigacion Forestal, C.P. 6201, Santa Cruz de la Sierra, Bolivia. ; National Institute for Research in Amazonia (INPA), C.P. 478, Manaus, Amazonas, CEP 69011-970, Brazil. ; 1] FOMABO, Manejo Forestal en las Tierras Tropicales de Bolivia, Sacta, Bolivia. [2] Escuela de Ciencias Forestales (ESFOR), Universidad Mayor de San Simon (UMSS), Sacta, Bolivia. ; Universidad Estatal Amazonica, Facultad de Ingenieria Ambiental, Paso lateral km 2 1/2 via Napo, Puyo, Pastaza, Ecuador. ; National Institute for Research in Amazonia (INPA), C.P. 2223, 69080-971, Manaus, Amazonas, Brazil. ; Universidad Autonoma del Beni, Campus Universitario, Av. Ejercito Nacional, Riberalta, Beni, Bolivia. ; 1] Instituto Boliviano de Investigacion Forestal, C.P. 6201, Santa Cruz de la Sierra, Bolivia. [2] Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands. ; 1] Center for Tropical Conservation, Duke University, Box 90381, Durham, North Carolina 27708, USA. [2] The Field Museum, 1400 South Lake Shore Drive, Chicago, Illinois 60605-2496, USA. ; Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands. ; Universidad Nacional de la Amazonia Peruana, Iquitos, Loreto, Peru. ; Instituto de Investigaciones para el Desarrollo Forestal (INDEFOR), Universidad de Los Andes, Facultad de Ciencias Forestales y Ambientales, Conjunto Forestal, C.P. 5101, Merida, Venezuela. ; Iwokrama International Centre for Rainforest Conservation and Development, 77 High Street Kingston, Georgetown, Guyana. ; Museu Paraense Emilio Goeldi, Av. Magalhaes Barata, 376 - Sao Braz, CEP 66040-170, Belem PA, Brazil. ; UFRA, Av. Presidente Tancredo Neves 2501, CEP 66.077-901, Belem, Para, Brazil. ; Museu Universitario, Universidade Federal do Acre, Rio Branco AC 69910-900, Brazil. ; European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, Via Enrico Fermi 274, 21010 Ispra, Italy. ; 1] Naturalis Biodiversity Center, PO Box, 2300 RA, Leiden, The Netherlands. [2] Ecology and Biodiversity Group, Utrecht University, PO Box 80084, 3508 TB Utrecht, The Netherlands. ; Museo de Historia Natural Alcide D'Orbigny, Av. Potosi no 1458, Cochabamba, Bolivia. ; 1] School of Earth and Environmental Science, James Cook University, Cairns, Queensland 4870, Australia. [2] Centre for Tropical Environmental and Sustainability Science (TESS) and School of Marine and Tropical Biology, James Cook University, Cairns, Queensland 4878, Australia. ; 1] Northumbria University, School of Geography, Ellison Place, Newcastle upon Tyne, Newcastle NE1 8ST, UK. [2] University of Wisconsin, Milwaukee, Wisconsin 53202, USA. [3] Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panama, Republic of Panama. ; Van der Hout Forestry Consulting, Jan Trooststraat 6, 3078 HP Rotterdam, The Netherlands. ; Universidade Estadual de Campinas, NEPAM, Rua dos Flamboyants, 155- Cidade Universitaria Zeferino Vaz, Campinas, CEP 13083-867, Sao Paulo, Brazil. ; 1] Universidad Autonoma del Beni, Campus Universitario, Av. Ejercito Nacional, Riberalta, Beni, Bolivia. [2] Centro de Investigacion y Promocion del Campesinado, regional Norte Amazonico, C/ Nicanor Gonzalo Salvatierra N degrees 362, Casilla 16, Riberalta, Bolivia. ; Tropenbos International, PO Box 232, 6700 AE Wageningen, The Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25788097" target="_blank"〉PubMed〈/a〉