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- ItemEurope’s renewable energy directive poised to harm global forests([London] : Nature Publishing Group UK, 2018) Searchinger, Timothy D.; Beringer, Tim; Holtsmark, Bjart; Kammen, Daniel M.; Lambin, Eric F.; Lucht, Wolfgang; Raven, Peter; van Ypersele, Jean-PascalThis comment raises concerns regarding the way in which a new European directive, aimed at reaching higher renewable energy targets, treats wood harvested directly for bioenergy use as a carbon-free fuel. The result could consume quantities of wood equal to all Europe’s wood harvests, greatly increase carbon in the air for decades, and set a dangerous global example.
- ItemEstimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey(London : Springer Nature, 2020) Horton, Benjamin P.; Khan, Nicole S.; Cahill, Niamh; Lee, Janice S. H.; Shaw, Timothy A.; Garner, Andra J.; Kemp, Andrew C.; Engelhart, Simon E.; Rahmstorf, StefanSea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions. To elicit projections from members of the scientific community regarding future global mean sea-level (GMSL) rise, we repeated a survey originally conducted five years ago. Under Representative Concentration Pathway (RCP) 2.6, 106 experts projected a likely (central 66% probability) GMSL rise of 0.30–0.65 m by 2100, and 0.54–2.15 m by 2300, relative to 1986–2005. Under RCP 8.5, the same experts projected a likely GMSL rise of 0.63–1.32 m by 2100, and 1.67–5.61 m by 2300. Expert projections for 2100 are similar to those from the original survey, although the projection for 2300 has extended tails and is higher than the original survey. Experts give a likelihood of 42% (original survey) and 45% (current survey) that under the high-emissions scenario GMSL rise will exceed the upper bound (0.98 m) of the likely range estimated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which is considered to have an exceedance likelihood of 17%. Responses to open-ended questions suggest that the increases in upper-end estimates and uncertainties arose from recent influential studies about the impact of marine ice cliff instability on the meltwater contribution to GMSL rise from the Antarctic Ice Sheet. © 2020, The Author(s).
- ItemFormation and composition of the UTLS aerosol(London : Springer Nature, 2019) Martinsson, Bengt G.; Friberg, Johan; Sandvik, Oscar S.; Hermann, Markus; van Velthoven, Peter F. J.; Zahn, AndreasStratospheric aerosol has long been seen as a pure mixture of sulfuric acid and water. Recent measurements, however, found a considerable carbonaceous fraction extending at least 8 km into the stratosphere. This fraction affects the aerosol optical depth (AOD) and the radiative properties, and hence the radiative forcing and climate impact of the stratospheric aerosol. Here we present an investigation based on a decade (2005–2014) of airborne aerosol sampling at 9–12 km altitude in the tropics and the northern hemisphere (NH) aboard the IAGOS-CARIBIC passenger aircraft. We find that the chemical composition of tropospheric aerosol in the tropics differs markedly from that at NH midlatitudes, and, that the carbonaceous stratospheric aerosol is oxygen-poor compared to the tropospheric aerosol. Furthermore, the carbonaceous and sulfurous components of the aerosol in the lowermost stratosphere (LMS) show strong increases in concentration connected with springtime subsidence from overlying stratospheric layers. The LMS concentrations significantly exceed those in the troposphere, thus clearly indicating a stratospheric production of not only the well-established sulfurous aerosol, but also a considerable but less understood carbonaceous component. © 2019, The Author(s).
- ItemChapter scientists in the IPCC AR5-experience and lessons learned(Amsterdam [u.a.] : Elsevier, 2015) Schulte-Uebbing, Lena; Hansen, Gerrit; Hernández, Ariel Macaspac; Winter, MartenIPCC Assessment Reports provide timely and accurate information on anthropogenic climate change to policy makers and the public. The reports are written by hundreds of scientists in a voluntary, collaborative effort. Growing amounts of literature and complex procedural and administrative requirements, however, make this effort a substantial management challenge next to a scientific one. During the 5th Assessment Cycle, IPCC Working Groups II and III initiated a program that recruited volunteer scientific assistants who provided technical and logistical support to author teams. In this paper we describe and analyze strengths and weaknesses of this ‘Chapter Scientist program’, based on an extensive survey among Chapter Scientists (CS) and interviews with other stakeholders. We conclude that the program was a useful innovation that that enabled authors to focus more on their core scientific tasks and that contributed to improving the quality of the assessment. We highly recommend similar programs for future scientific assessments. Key criteria for success that we identified are (a) involvement of early-career scientists as CS, (b) close integration of CS in the assessment process, (c) recruitment of CS through an open call to achieve transparency, and (d) provision of funds for such a program to support travel costs and compensation of CS.
- ItemClimate mobilities, rights and justice: Complexities and particularities(Lausanne : Frontiers Media, 2022) Farbotko, Carol; Thornton, Fanny; Mayrhofer, Monika; Hermann, ElfriedeClimate mobility revolves around issues of justice and human rights, whether this be concerning its causes, expression or handling. This paper examines the justice-rights nexus as it relates to climate mobility, highlighting how the two spheres converge and diverge. It works with four case studies exploring the complexity of rights and justice in the climate mobility context. Our case studies are diverse, in terms of the mobility types concerned and the rights and justice-based issues involved. We show that conceptualizing or achieving just or righteous outcomes is neither certain nor a uniform pursuit when it comes to climate mobility. Rather, there are many divergences–by those who claim rights or justice, and those asked to respond. We present a complex and contested space, highlight the importance of approaching justice and rights matters contextually, and with special attention to particularities when climate mobility is at issue.
- ItemDiverging importance of drought stress for maize and winter wheat in Europe([London] : Nature Publishing Group UK, 2018) Webber, Heidi; Ewert, Frank; Olesen, Jørgen E.; Müller, Christoph; Fronzek, Stefan; Ruane, Alex C.; Bourgault, Maryse; Martre, Pierre; Ababaei, Behnam; Bindi, Marco; Ferrise, Roberto; Finger, Robert; Fodor, Nándor; Gabaldón-Leal, Clara; Gaiser, Thomas; Jabloun, Mohamed; Kersebaum, Kurt-Christian; Lizaso, Jon I.; Lorite, Ignacio J.; Manceau, Loic; Moriondo, Marco; Nendel, Claas; Rodríguez, Alfredo; Ruiz-Ramos, Margarita; Semenov, Mikhail A.; Siebert, Stefan; Stella, Tommaso; Stratonovitch, Pierre; Trombi, Giacomo; Wallach, DanielUnderstanding the drivers of yield levels under climate change is required to support adaptation planning and respond to changing production risks. This study uses an ensemble of crop models applied on a spatial grid to quantify the contributions of various climatic drivers to past yield variability in grain maize and winter wheat of European cropping systems (1984–2009) and drivers of climate change impacts to 2050. Results reveal that for the current genotypes and mix of irrigated and rainfed production, climate change would lead to yield losses for grain maize and gains for winter wheat. Across Europe, on average heat stress does not increase for either crop in rainfed systems, while drought stress intensifies for maize only. In low-yielding years, drought stress persists as the main driver of losses for both crops, with elevated CO2 offering no yield benefit in these years.
- ItemThe future is now: Climate displacement and human rights obligations—a note on recent developments in the UN Human Rights Committee(Lausanne : Frontiers Media, 2022) Thornton, FannyAlthough climate litigation—or the pursuit of legal resolve of matters stemming from anthropogenic climate change—has been growing around the world, climate mobility is seldom at the heart of relevant case law. It is human rights law bodies, in particular, which have nevertheless begun to progress legal developments in the sphere of climate mobility. This note looks at a 2022 determination by the UN Human Rights Committee concerning the habitability of a small island setting—Australia's Torres Strait Islands—under climate change conditions and the legal responsibilities of nation states to abide by their international human rights obligations in implementing timely adaptation measures now which could help to ensure continued habitation.