#Carbon #cycle: #Global #warming then and now (Nature Geoscience, abstract)

[Source: Nature Geoscience, full page: (LINK). Abstract, edited.]

Nature Geoscience | News and Views

Carbon cycle: Global warming then and now

Peter Stassen1

Journal name: Nature Geoscience – Year published: (2016) – DOI: doi:10.1038/ngeo2691

Published online 21 March 2016

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A rapid warming event 55.8 million years ago was caused by extensive carbon emissions. The rate of change of carbon and oxygen isotopes in marine shelf sediments suggests that carbon emission rates were much slower than anthropogenic emissions.

Subject terms: Carbon cycle • Palaeoclimate

Keywords: Research; Abstracts; Climate Change; Global Warming.

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Enhanced #Atlantic #sea-level rise relative to the #Pacific under high #carbon #emission rates (Nature Geoscience, abstract)

[Source: Nature Geoscience, full page: (LINK). Abstract, edited.]

Nature Geoscience | Letter

Enhanced Atlantic sea-level rise relative to the Pacific under high carbon emission rates [   R   ]

J. P. Krasting, J. P. Dunne, R. J. Stouffer & R. W. Hallberg

Journal name: Nature Geoscience  – Year published: (2016) – DOI: doi:10.1038/ngeo2641

Received 01 May 2015  – Accepted 23 December 2015  – Published online 01 February 2016

 

Abstract

Thermal expansion of the ocean in response to warming is an important component of historical sea-level rise1. Observational studies show that the Atlantic and Southern oceans are warming faster than the Pacific Ocean2, 3, 4, 5. Here we present simulations using a numerical atmospheric-ocean general circulation model with an interactive carbon cycle to evaluate the impact of carbon emission rates, ranging from 2 to 25 GtC yr−1, on basin-scale ocean heat uptake and sea level. For simulations with emission rates greater than 5 GtC yr−1, sea-level rise is larger in the Atlantic than Pacific Ocean on centennial timescales. This basin-scale asymmetry is related to the shorter flushing timescales and weakening of the overturning circulation in the Atlantic. These factors lead to warmer Atlantic interior waters and greater thermal expansion. In contrast, low emission rates of 2 and 3 GtC yr−1 will cause relatively larger sea-level rise in the Pacific on millennial timescales. For a given level of cumulative emissions, sea-level rise is largest at low emission rates. We conclude that Atlantic coastal areas may be particularly vulnerable to near-future sea-level rise from present-day high greenhouse gas emission rates.

Subject terms: Climate and Earth system modelling • Climate change • Climate-change impacts • Physical oceanography

Keywords: Research; Abstracts; Climate Change.

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Limited #tolerance by #insects to high #temperatures across #tropical elevational gradients and the implications of #global #warming for #extinction (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Limited tolerance by insects to high temperatures across tropical elevational gradients and the implications of global warming for extinction [   R   ]

Carlos García-Robledo a,b,1, Erin K. Kuprewicz a, Charles L. Staines b, Terry L. Erwin b, and W. John Kress a

Author Affiliations: aDepartment of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012; bDepartment of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012

Edited by Douglas Futuyma, and approved November 24, 2015 (received for review April 20, 2015)

 

Significance

Tolerance to high temperatures will determine the survival of animal species under projected global warming. Surprisingly little research has been conducted to elucidate how this trait changes in organisms living at different elevations of similar latitudes, especially in the tropics. DNA barcodes demonstrate that insect species previously thought to have broad elevational distributions and phenotypically plastic thermal tolerances actually comprise cryptic species complexes. These cryptic species occupy discrete elevational ranges, and their thermal tolerances seem to be locally adapted to temperatures in their life zones. The combination of high species endemism and local adaptation to temperature regimes may increase the extinction risk of high-elevation insects in a warming world.

 

Abstract

The critical thermal maximum (CTmax), the temperature at which motor control is lost in animals, has the potential to determine if species will tolerate global warming. For insects, tolerance to high temperatures decreases with latitude, suggesting that similar patterns may exist along elevational gradients as well. This study explored how CTmax varies among species and populations of a group of diverse tropical insect herbivores, the rolled-leaf beetles, across both broad and narrow elevational gradients. Data from 6,948 field observations and 8,700 museum specimens were used to map the elevational distributions of rolled-leaf beetles on two mountains in Costa Rica. CTmax was determined for 1,252 individual beetles representing all populations across the gradients. Initial morphological identifications suggested a total of 26 species with populations at different elevations displaying contrasting upper thermal limits. However, compared with morphological identifications, DNA barcodes (cytochrome oxidase I) revealed significant cryptic species diversity. DNA barcodes identified 42 species and haplotypes across 11 species complexes. These 42 species displayed much narrower elevational distributions and values of CTmax than the 26 morphologically defined species. In general, species found at middle elevations and on mountaintops are less tolerant to high temperatures than species restricted to lowland habitats. Species with broad elevational distributions display high CTmax throughout their ranges. We found no significant phylogenetic signal in CTmax, geography, or elevational range. The narrow variance in CTmax values for most rolled-leaf beetles, especially high-elevation species, suggests that the risk of extinction of insects may be substantial under some projected rates of global warming.

CephaloleiaChelobasis – CO1 – CTmax – thermal limits

 

Footnotes

1To whom correspondence should be addressed. Email: garciac@si.edu.

Author contributions: C.G.-R., E.K.K., T.L.E., and W.J.K. designed research; C.G.-R., E.K.K., and C.L.S. performed research; C.G.-R. and W.J.K. contributed new reagents/analytic tools; C.G.-R. and E.K.K. analyzed data; and C.G.-R., E.K.K., C.L.S., T.L.E., and W.J.K. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

Data deposition: The DNA sequences reported in this paper have been deposited in the GenBank database, dx.doi.org/10.5883/DS-BOFCR (accession nos. KU357054KU358485).

This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1507681113/-/DCSupplemental.

http://www.pnas.org/preview_site/misc/userlicense.xhtml

Keywords: Research; Abstracts; Climate Change; Global Warming; Insects.

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#Amplification of #ElNiño by #cloud longwave coupling to #atmospheric #circulation (Nature Geoscience, abstract)

[Source: Nature Geoscience, full page: (LINK). Abstract, edited.]

Nature Geoscience | Letter

Amplification of El Niño by cloud longwave coupling to atmospheric circulation [   R   ]

Gaby Rädel, Thorsten Mauritsen, Bjorn Stevens, Dietmar Dommenget, Daniela Matei, Katinka Bellomo & Amy Clement

Journal name: Nature Geoscience – Year published: (2016) DOI: doi:10.1038/ngeo2630

Received 08 July 2015 – Accepted 02 December 2015 – Published online 04 January 2016

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The El Niño/Southern Oscillation (ENSO) is the dominant mode of inter-annual variability, with major impacts on social and ecological systems through its influence on extreme weather, droughts and floods. The ability to forecast El Niño, as well as anticipate how it may change with warming, requires an understanding of the underlying physical mechanisms that drive it. Among these, the role of atmospheric processes remains poorly understood. Here we present numerical experiments with an Earth system model, with and without coupling of cloud radiative effects to the circulation, suggesting that clouds enhance ENSO variability by a factor of two or more. Clouds induce heating in the mid and upper troposphere associated with enhanced high-level cloudiness over the El Niño region, and low-level clouds cool the lower troposphere in the surrounding regions. Together, these effects enhance the coupling of the atmospheric circulation to El Niño surface temperature anomalies, and thus strengthen the positive Bjerknes feedback mechanism between west Pacific zonal wind stress and sea surface temperature gradients. Behaviour consistent with the proposed mechanism is robustly represented in other global climate models and in satellite observations. The mechanism suggests that the response of ENSO amplitude to climate change will in part be determined by a balance between increasing cloud longwave feedback and a possible reduction in the area covered by upper-level clouds.

(…)

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Subject terms: Atmospheric dynamics • Climate and Earth system modelling • Physical oceanography

Keywords: Research; Abstracts; Climate Change.

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#Weather-Related #Flood and #Landslide #Damage: A #Risk #Index for #Italian #Regions (Plos One, abstract)

[Source: PLoS One, full page: (LINK). Abstract, edited.]

Open Access / Peer-reviewed / Research Article

Weather-Related Flood and Landslide Damage: A Risk Index for Italian Regions [   R   ]

Alessandro Messeri,  Marco Morabito,  Gianni Messeri,  Giada Brandani,  Martina Petralli,  Francesca Natali,  Daniele Grifoni,  Alfonso Crisci,  … Gianfranco Gensini,  Simone Orlandini

Published: December 29, 2015 / DOI: 10.1371/journal.pone.0144468

 

Abstract

The frequency of natural hazards has been increasing in the last decades in Europe and specifically in Mediterranean regions due to climate change. For example heavy precipitation events can lead to disasters through the interaction with exposed and vulnerable people and natural systems. It is therefore necessary a prevention planning to preserve human health and to reduce economic losses. Prevention should mainly be carried out with more adequate land management, also supported by the development of an appropriate risk prediction tool based on weather forecasts. The main aim of this study is to investigate the relationship between weather types (WTs) and the frequency of floods and landslides that have caused damage to properties, personal injuries, or deaths in the Italian regions over recent decades. In particular, a specific risk index (WT-FLARI) for each WT was developed at national and regional scale. This study has identified a specific risk index associated with each weather type, calibrated for each Italian region and applicable to both annual and seasonal levels. The risk index represents the seasonal and annual vulnerability of each Italian region and indicates that additional preventive actions are necessary for some regions. The results of this study represent a good starting point towards the development of a tool to support policy-makers, local authorities and health agencies in planning actions, mainly in the medium to long term, aimed at the weather damage reduction that represents an important issue of the World Meteorological Organization mission.

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Citation: Messeri A, Morabito M, Messeri G, Brandani G, Petralli M, Natali F, et al. (2015) Weather-Related Flood and Landslide Damage: A Risk Index for Italian Regions. PLoS ONE 10(12): e0144468. doi:10.1371/journal.pone.0144468

Editor: Moncho Gomez-Gesteira, University of Vigo, SPAIN

Received: September 10, 2015; Accepted: November 18, 2015; Published: December 29, 2015

Copyright: © 2015 Messeri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Data Availability: All relevant data are within the paper and in a specific public repository (https://github.com/meteosalute/weather_landslide).

Funding: This study was funded by the European Project Horizon 2020 (H2020-DRS-2014) Culture And RISkmanagement in Man-made and Natural Disasters (CARISMAND—G.A. 635748—Horizon 2020).

Competing interests: The authors have declared that no competing interests exist.

Keywords: Research; Abstracts; Extreme Weather; Floods; Climate Change; Italy; Disaster Preparedness.

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Detecting long-term #metabolic #shifts using isotopomers: CO2-driven suppression of photorespiration in C3 #plants over the 20th #century (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Detecting long-term metabolic shifts using isotopomers: CO2-driven suppression of photorespiration in C3 plants over the 20th century [      ]

Ina Ehlers a,1, Angela Augusti a,1,2, Tatiana R. Betson a, Mats B. Nilsson b, John D. Marshall b,c, and Jürgen Schleucher a,3

Author Affiliations: aDepartment of Medical Biochemistry & Biophysics, Umeå University, 901 87 Umea, Sweden; bDepartment of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden; cDepartment of Forest, Rangeland, and Fire Sciences, University of Idaho, Moscow, ID 83844-1133

Edited by Katherine H. Freeman, Pennsylvania State University, University Park, PA, and approved November 9, 2015 (received for review July 26, 2015)

Significance

Decadal-scale metabolic responses of plants to environmental changes, including the magnitude of the “CO2 fertilization” effect, are a major knowledge gap in Earth system models, in agricultural models, and for societal adaptation. We introduce intramolecular isotope distributions (isotopomers) as a methodology for detecting shifts in plant carbon metabolism over long times. Trends in a deuterium isotopomer ratio allow quantification of a biogeochemically relevant shift in the metabolism of C3 plants toward photosynthesis, driven by increasing atmospheric CO2 since industrialization. Isotopomers strongly increase the information content of isotope archives, and may therefore reveal long-term acclimation or adaptations to environmental changes in general. The metabolic information encoded in isotopomers of plant archives bridges a fundamental gap between experimental plant science and paleoenvironmental studies.

 

Abstract

Terrestrial vegetation currently absorbs approximately a third of anthropogenic CO2 emissions, mitigating the rise of atmospheric CO2. However, terrestrial net primary production is highly sensitive to atmospheric CO2 levels and associated climatic changes. In C3 plants, which dominate terrestrial vegetation, net photosynthesis depends on the ratio between photorespiration and gross photosynthesis. This metabolic flux ratio depends strongly on CO2 levels, but changes in this ratio over the past CO2 rise have not been analyzed experimentally. Combining CO2 manipulation experiments and deuterium NMR, we first establish that the intramolecular deuterium distribution (deuterium isotopomers) of photosynthetic C3 glucose contains a signal of the photorespiration/photosynthesis ratio. By tracing this isotopomer signal in herbarium samples of natural C3 vascular plant species, crops, and a Sphagnum moss species, we detect a consistent reduction in the photorespiration/photosynthesis ratio in response to the ∼100-ppm CO2 increase between ∼1900 and 2013. No difference was detected in the isotopomer trends between beet sugar samples covering the 20th century and CO2 manipulation experiments, suggesting that photosynthetic metabolism in sugar beet has not acclimated to increasing CO2 over >100 y. This provides observational evidence that the reduction of the photorespiration/photosynthesis ratio was ca. 25%. The Sphagnum results are consistent with the observed positive correlations between peat accumulation rates and photosynthetic rates over the Northern Hemisphere. Our results establish that isotopomers of plant archives contain metabolic information covering centuries. Our data provide direct quantitative information on the “CO2 fertilization” effect over decades, thus addressing a major uncertainty in Earth system models.

isotopomer – acclimation – deuterium – CO2 fertilization – atmospheric change

 

Footnotes

1I.E. and A.A. contributed equally to this work.

2Present address: Institute of Agro-environmental and Forest Biology, National Council of Research, 05010 Porano (TR), Italy.

3To whom correspondence should be addressed. Email: jurgen.schleucher@chem.umu.se.

Author contributions: I.E., A.A., and J.S. designed research; I.E., A.A., and J.S. performed research; T.R.B. and M.B.N. contributed new reagents/analytic tools; I.E., A.A., T.R.B., M.B.N., J.D.M., and J.S. analyzed data; and I.E., A.A., T.R.B., M.B.N., J.D.M., and J.S. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1504493112/-/DCSupplemental.

Freely available online through the PNAS open access option. http://www.pnas.org/preview_site/misc/userlicense.xhtml

Keywords: Research; Abstracts; Climate Change; Biodiversity.

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#Deaths From #Disasters Double This Year as #Planet Heats Up (Bloomberg, Dec. 18 ‘15)

[Source: Bloomberg, full page: (LINK).]

Deaths From Disasters Double This Year as Planet Heats Up [   !   ]

At least 26,000 people died in heat waves, earthquakes, floods and other disasters during a year that was probably the warmest on record, more than double the number of deaths in 2014, Swiss Re AG said in an annual report.

(…)

Keywords: Global Warming; Climate Change; Extreme Weather.

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