AGW Observer

Observations of anthropogenic global warming

New research, February 11, 2016

Posted by Ari Jokimäki on February 11, 2016

Some new papers from last few days:

The roles of external forcing and natural variability in global warming hiatuses

Evaluating the impact of U.S. Historical Climatology Network homogenization using the U.S. Climate Reference Network

Significant recent warming over the northern Tibetan Plateau from ice core δ18O records (open access)

Mid-2000s North Atlantic shift: Heat budget and circulation changes

A large increase in US methane emissions over the past decade inferred from satellite data and surface observations

Transatlantic flight times and climate change (open access)

Impact of progressive global warming on the global-scale yield of maize and soybean (open access)

Sequestration of carbon in the deep Atlantic during the last glaciation

Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD

Estimates of late middle Eocene pCO2 based on stomatal density of modern and fossil Nageia leaves (open access)

Snow and albedo climate change impacts across the United States Northern Great Plains (open access)

Observed high-altitude warming and snow cover retreat over Tibet and the Himalayas enhanced by black carbon aerosols (open access)

Weather preferences of French tourists: lessons for climate change impact assessment

Evaluating forest transition based on a multi-scale approach: forest area dynamics in Switzerland 1850–2000

Observed trends and impacts of tropical cyclones in the Philippines

From global to regional and back again: common climate stressors of marine ecosystems relevant for adaptation across five ocean warming hotspots

Crossing regimes of temperature dependence in animal movement

Global trends of aerosol optical thickness using the ensemble empirical mode decomposition method

The impact of observational sampling on time series of global 0–700 m ocean average temperature: a case study

Winter precipitation and snow accumulation drive the methane sink or source strength of Arctic tussock tundra

Agricultural production and greenhouse gas emissions from world regions—The major trends over 40 years

Assessing local climate vulnerability and winegrowers’ adaptive processes in the context of climate change

Mediterranean and temperate treelines are controlled by different environmental drivers

Geographic divergence in upper thermal limits across insect life stages: does behavior matter?

Paradoxical acclimation responses in the thermal performance of insect immunity

Posted in Adaptation & Mitigation, Climate science, Global warming effects | Leave a Comment »

New research, February 5, 2016

Posted by Ari Jokimäki on February 5, 2016

Some new papers from last few days:

Historical construction costs of global nuclear power reactors

Timing and associated climate change of a 2 °C global warming

Overestimated Arctic warming and underestimated Eurasia mid-latitude warming in CMIP5 simulations

Mechanisms for stronger warming over drier ecoregions observed since 1979

Running dry: The U.S. Southwest’s drift into a drier climate state

Spatiotemporal drought variability in the Mediterranean over the last 900 years

Simulated differences in 21st century aridity due to different scenarios of greenhouse gases and aerosols (open access)

Climate change and anthropogenic impacts on the rapid shrinkage of Lake Urmia

Anthropogenic footprint of climate change in the June 2013 northern India flood

Spatial and temporal features of summer extreme temperature over China during 1960–2013

Enhancement of Arctic storm activity in relation to permafrost degradation in eastern Siberia

How do carbon cycle uncertainties affect IPCC temperature projections? (open access)

Large contribution to inland water CO2 and CH4 emissions from very small ponds

Linear and nonlinear effects of dominant drivers on the trends in global and regional land carbon uptake: 1959 to 2013

Spatial and temporal oxygen isotope variability in northern Greenland – implications for a new climate record over the past millennium (open access)

Projections of glacier change in the Altai Mountains under twenty-first century climate scenarios

Predictability of the Arctic sea-ice edge

On the potential for abrupt Arctic winter sea-ice loss

Climatic warming in China according to a homogenized data set from 2419 stations (open access)

Statistical models for the pattern of sea surface temperature in the North Atlantic during 1973–2008

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

Phenological change in a spring ephemeral: implications for pollination and plant reproduction

Grassland responses to increased rainfall depend on the timescale of forcing

Life cycle environmental impacts and costs of beer production and consumption in the UK (open access)

The Anthropocene: a conspicuous stratigraphical signal of anthropogenic changes in production and consumption across the biosphere (open access)

Posted in Adaptation & Mitigation, Climate science, Global warming effects | Leave a Comment »

Papers on ice sheet collapse

Posted by Ari Jokimäki on February 3, 2016

This is a list of papers on ice sheet collapse. The list is not complete, and will most likely be updated in future in order to make it more thorough and more representative.

Potential sea-level rise from Antarctic ice-sheet instability constrained by observations – Ritz et al. (2015)
Abstract: Large parts of the Antarctic ice sheet lying on bedrock below sea level may be vulnerable to marine-ice-sheet instability (MISI), a self-sustaining retreat of the grounding line triggered by oceanic or atmospheric changes. There is growing evidence that MISI may be underway throughout the Amundsen Sea embayment (ASE), which contains ice equivalent to more than a metre of global sea-level rise. If triggered in other regions, the centennial to millennial contribution could be several metres. Physically plausible projections are challenging: numerical models with sufficient spatial resolution to simulate grounding-line processes have been too computationally expensive to generate large ensembles for uncertainty assessment, and lower-resolution model projections rely on parameterizations that are only loosely constrained by present day changes. Here we project that the Antarctic ice sheet will contribute up to 30 cm sea-level equivalent by 2100 and 72 cm by 2200 (95% quantiles) where the ASE dominates. Our process-based, statistical approach gives skewed and complex probability distributions (single mode, 10 cm, at 2100; two modes, 49 cm and 6 cm, at 2200). The dependence of sliding on basal friction is a key unknown: nonlinear relationships favour higher contributions. Results are conditional on assessments of MISI risk on the basis of projected triggers under the climate scenario A1B (ref. 9), although sensitivity to these is limited by theoretical and topographical constraints on the rate and extent of ice loss. We find that contributions are restricted by a combination of these constraints, calibration with success in simulating observed ASE losses, and low assessed risk in some basins. Our assessment suggests that upper-bound estimates from low-resolution models and physical arguments (up to a metre by 2100 and around one and a half by 2200) are implausible under current understanding of physical mechanisms and potential triggers.
Citation: Catherine Ritz, Tamsin L. Edwards, Gaël Durand, Antony J. Payne, Vincent Peyaud, Richard C. A. Hindmarsh, Nature 528, 115–118 (03 December 2015) doi:10.1038/nature16147.

Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica – Joughin et al. (2014)
Abstract: Resting atop a deep marine basin, the West Antarctic Ice Sheet has long been considered prone to instability. Using a numerical model, we investigated the sensitivity of Thwaites Glacier to ocean melt and whether its unstable retreat is already under way. Our model reproduces observed losses when forced with ocean melt comparable to estimates. Simulated losses are moderate (1 mm per year of sea-level rise) collapse in the different simulations within the range of 200 to 900 years.
Citation: Ian Joughin, Benjamin E. Smith, Brooke Medley, Science 16 May 2014: Vol. 344, Issue 6185, pp. 735-738, DOI: 10.1126/science.1249055.

Where might we find evidence of a Last Interglacial West Antarctic Ice Sheet collapse in Antarctic ice core records? – Bradley et al. (2012) [FULL TEXT]
Abstract: Abundant indirect evidence suggests that the West Antarctic Ice Sheet (WAIS) reduced in size during the Last Interglacial (LIG) compared to the Holocene. This study explores this possibility by comparing, for the first time, ice core stable isotope records for the LIG with output from a glacio-isostatic adjustment (GIA) model. The results show that ice core records from East Antarctica are remarkably insensitive to vertical movement of the solid land motion driven by a simulated hypothetical collapse of the WAIS. However, new and so far unexplored sites are identified which are sensitive to the isostatic signal associated with WAIS collapse and so ice core proxy data from these sites would be effective in testing this hypothesis further.
Citation: S.L. Bradley, M. Siddall, G.A. Milne, V. Masson-Delmotte, E. Wolff, Global and Planetary Change, Volumes 88–89, May 2012, Pages 64–75, doi: 10.1016/j.gloplacha.2012.03.004.

Stability of the West Antarctic ice sheet in a warming world – Joughin & Alley (2011) [FULL TEXT]
Abstract: Ice sheets are expected to shrink in size as the world warms, which in turn will raise sea level. The West Antarctic ice sheet is of particular concern, because it was probably much smaller at times during the past million years when temperatures were comparable to levels that might be reached or exceeded within the next few centuries. Much of the grounded ice in West Antarctica lies on a bed that deepens inland and extends well below sea level. Oceanic and atmospheric warming threaten to reduce or eliminate the floating ice shelves that buttress the ice sheet at present. Loss of the ice shelves would accelerate the flow of non-floating ice near the coast. Because of the slope of the sea bed, the consequent thinning could ultimately float much of the ice sheet’s interior. In this scenario, global sea level would rise by more than three metres, at an unknown rate. Simplified analyses suggest that much of the ice sheet will survive beyond this century. We do not know how likely or inevitable eventual collapse of the West Antarctic ice sheet is at this stage, but the possibility cannot be discarded. For confident projections of the fate of the ice sheet and the rate of any collapse, further work including the development of well-validated physical models will be required.
Citation: Ian Joughin, Richard B. Alley, Nature Geoscience 4, 506–513 (2011) doi:10.1038/ngeo1194.

A new projection of sea level change in response to collapse of marine sectors of the Antarctic Ice Sheet – Gomez et al. (2010) [FULL TEXT]
Abstract: We present gravitationally self-consistent predictions of sea level change that would follow the disappearance of either the West Antarctic Ice Sheet (WAIS) or marine sectors of the East Antarctic Ice Sheet (EAIS). Our predictions are based on a state-of-the-art pseudo-spectral sea level algorithm that incorporates deformational, gravitational and rotational effects on sea level, as well as the migration of shorelines due to both local sea-level variations and changes in the extent of marine-based ice cover. If we define the effective eustatic value (EEV) as the geographically uniform rise in sea level once all marine-based sectors have been filled with water, then we find that some locations can experience a sea level rise that is ∼40 per cent higher than the EEV. This enhancement is due to the migration of water away from the zone of melting in response to the loss of gravitational attraction towards the ice sheet (load self-attraction), the expulsion of water from marine areas as these regions rebound due to the unloading, and the feedback into sea level of a contemporaneous perturbation in Earth rotation. In the WAIS case, this peak enhancement is twice the value predicted in a previous projection that did not include expulsion of water from exposed marine-sectors of the West Antarctic or rotational feedback. The peak enhancements occur over the coasts of the United States and in the Indian Ocean in the WAIS melt scenario, and over the south Atlantic and northwest Pacific in the EAIS scenario. We conclude that accurate projections of the sea level hazard associated with ongoing global warming should be based on a theory that includes the complete suite of physical processes described above.
Citation: Natalya Gomez, Jerry X. Mitrovica, Mark E. Tamisiea, Peter U. Clark, Geophys. J. Int. (2010) 180(2):623-634. doi: 10.1111/j.1365-246X.2009.04419.x.

Record of a Mid-Pleistocene depositional anomaly in West Antarctic continental margin sediments: an indicator for ice-sheet collapse? – Hillenbrand & Frederichs (2009)
Abstract: Modern global warming is likely to cause future melting of Earth’s polar ice sheets that may result in dramatic sea-level rise. A possible collapse of the West Antarctic Ice Sheet (WAIS) alone, which is considered highly vulnerable as it is mainly based below sea level, may raise global sea level by up to 5–6 m. Despite the importance of the WAIS for changes in global sea level, its response to the glacial–interglacial cycles of the Quaternary is poorly constrained. Moreover, the geological evidence for the disintegration of the WAIS at some time within the last ca. 750 kyr, possibly during Marine Isotope Stage (MIS) 11 (424–374 ka), is ambiguous. Here we present physical properties, palaeomagnetic, geochemical and clay mineralogical data from a glaciomarine sedimentary sequence that was recovered from the West Antarctic continental margin in the Amundsen Sea and spans more than the last 1 Myr. Within the sedimentary sequence, proxies for biological productivity (such as biogenic opal and the barium/aluminum ratio) and the supply of lithogenic detritus from the West Antarctic hinterland (such as ice-rafted debris and clay minerals) exhibit cyclic fluctuations in accordance with the glacial–interglacial cycles of the Quaternary. A prominent depositional anomaly spans MIS 15–MIS 13 (621–478 ka). The proxies for biological productivity and lithogenic sediment supply indicate that this interval has the characteristics of a single, prolonged interglacial period. Even though no proxy suggests environmental conditions much different from today, we conclude that, if the WAIS collapsed during the last 800 kyr, then MIS 15–MIS 13 was the most likely time period. Apparently, the duration rather than the strength of interglacial conditions was the crucial factor for the WAIS drawdown. A comparison with various marine and terrestrial climate archives from around the world corroborates that unusual environmental conditions prevailed throughout MIS 15–MIS 13. Some of these anomalies are observed in the pelagic Southern Ocean and the South Atlantic and might originate in major ice-sheet drawdown in Antarctica, but further research is required to test this hypothesis.
Citation: C.-D. Hillenbrand, G. Kuhn, T. Frederichs, Quaternary Science Reviews, Volume 28, Issues 13–14, June 2009, Pages 1147–1159, doi: 10.1016/j.quascirev.2008.12.010.

Reassessment of the Potential Sea-Level Rise from a Collapse of the West Antarctic Ice Sheet – Bamber et al. (2009) [FULL TEXT]
Abstract: Theory has suggested that the West Antarctic Ice Sheet may be inherently unstable. Recent observations lend weight to this hypothesis. We reassess the potential contribution to eustatic and regional sea level from a rapid collapse of the ice sheet and find that previous assessments have substantially overestimated its likely primary contribution. We obtain a value for the global, eustatic sea-level rise contribution of about 3.3 meters, with important regional variations. The maximum increase is concentrated along the Pacific and Atlantic seaboard of the United States, where the value is about 25% greater than the global mean, even for the case of a partial collapse.
Citation: Jonathan L. Bamber, Riccardo E. M. Riva, Bert L. A. Vermeersen, Anne M. LeBrocq, Science 15 May 2009: Vol. 324, Issue 5929, pp. 901-903, DOI: 10.1126/science.1169335.

The Sea-Level Fingerprint of West Antarctic Collapse – Mitrovica et al. (2009) [FULL TEXT]
Abstract: Recent projections of sea-level rise after a future collapse of theWest Antarctic Ice Sheet (for example, the Fourth Intergovernmental Panel on Climate Change Assessment Report) assume that meltwater will spread uniformly (that is, eustatically) across the oceans once marine-based sectors of the West Antarctic are filled. A largely neglected 1977 study predicted that peak values would be 20% higher than the eustatic in the North Pacific and 5 to 10% higher along the U.S. coastline. We show, with use of a state-of-the-art theory, that the sea-level rise in excess of the eustatic value will be two to three times higher than previously predicted for U.S. coastal sites.
Citation: Jerry X. Mitrovica, Natalya Gomez, Peter U. Clark, Science 06 Feb 2009: Vol. 323, Issue 5915, pp. 753, DOI: 10.1126/science.1166510.

Modelling West Antarctic ice sheet growth and collapse through the past five million years – Pollard & DeConto (2009) [FULL TEXT]
Abstract: The West Antarctic ice sheet (WAIS), with ice volume equivalent to ~5 m of sea level, has long been considered capable of past and future catastrophic collapse. Today, the ice sheet is fringed by vulnerable floating ice shelves that buttress the fast flow of inland ice streams. Grounding lines are several hundred metres below sea level and the bed deepens upstream, raising the prospect of runaway retreat. Projections of future WAIS behaviour have been hampered by limited understanding of past variations and their underlying forcing mechanisms. Its variation since the Last Glacial Maximum is best known, with grounding lines advancing to the continental-shelf edges around ~15 kyr ago before retreating to near-modern locations by ~3 kyr ago. Prior collapses during the warmth of the early Pliocene epoch9 and some Pleistocene interglacials have been suggested indirectly from records of sea level and deep-sea-core isotopes, and by the discovery of open-ocean diatoms in subglacial sediments. Until now, however, little direct evidence of such behaviour has been available. Here we use a combined ice sheet/ice shelf model capable of high-resolution nesting with a new treatment of grounding-line dynamics and ice-shelf buttressing to simulate Antarctic ice sheet variations over the past five million years. Modelled WAIS variations range from full glacial extents with grounding lines near the continental shelf break, intermediate states similar to modern, and brief but dramatic retreats, leaving only small, isolated ice caps on West Antarctic islands. Transitions between glacial, intermediate and collapsed states are relatively rapid, taking one to several thousand years. Our simulation is in good agreement with a new sediment record (ANDRILL AND-1B) recovered from the western Ross Sea, indicating a long-term trend from more frequently collapsed to more glaciated states, dominant 40-kyr cyclicity in the Pliocene, and major retreats at marine isotope stage 31 (approx1.07 Myr ago) and other super-interglacials.
Citation: David Pollard, Robert M. DeConto, Nature 458, 329-332 (19 March 2009) | doi:10.1038/nature07809.

West Antarctic Ice Sheet collapse – the fall and rise of a paradigm – Vaughan (2008) [FULL TEXT]
Abstract: It is now almost 30 years since John Mercer (1978) first presented the idea that climate change could eventually cause a rapid deglaciation, or “collapse,” of a large part of the West Antarctic ice sheet (WAIS), raising world sea levels by 5 m and causing untold economic and social impacts. This idea, apparently simple and scientifically plausible, created a vision of the future, sufficiently alarming that it became a paradigm for a generation of researchers and provided an icon for the green movement. Through the 1990s, however, a lack of observational evidence for ongoing retreat in WAIS and improved understanding of the complex dynamics of ice streams meant that estimates of likelihood of collapse seemed to be diminishing. In the last few years, however, satellite studies over the relatively inaccessible Amundsen Sea sector of West Antarctica have shown clear evidence of ice sheet retreat showing all the features that might have been predicted for emergent collapse. These studies are re-invigorating the paradigm, albeit in a modified form, and debate about the future stability of WAIS. Since much of WAIS appears to be unchanging, it may, no longer be reasonable to suggest there is an imminent threat of a 5-m rise in sea level resulting from complete collapse of the West Antarctic ice sheet, but there is strong evidence that the Amundsen Sea embayment is changing rapidly. This area alone, contains the potential to raise sea level by around ~1.5 m, but more importantly it seems likely that it could, alter rapidly enough, to make a significant addition to the rate of sea-level rise over coming two centuries. Furthermore, a plausible connection between contemporary climate change and the fate of the ice sheet appears to be developing. The return of the paradigm presents a dilemma for policy-makers, and establishes a renewed set of priorities for the glaciological community. In particular, we must establish whether the hypothesized instability in WAIS is real, or simply an oversimplification resulting from inadequate understanding of the feedbacks that allow ice sheets to achieve equilibrium: and whether there is any likelihood that contemporary climate change could initiate collapse.
Citation: David G. Vaughan, Climatic Change, November 2008, Volume 91, Issue 1, pp 65-79, DOI: 10.1007/s10584-008-9448-3.

Glacier Surge After Ice Shelf Collapse – De Angelis & Skvarca (2003) [FULL TEXT]
Abstract: The possibility that the West Antarctic Ice Sheet will collapse as a consequence of ice shelf disintegration has been debated for many years. This matter is of concern because such an event would imply a sudden increase in sea level. Evidence is presented here showing drastic dynamic perturbations on former tributary glaciers that fed sections of the Larsen Ice Shelf on the Antarctic Peninsula before its collapse in 1995. Satellite images and airborne surveys allowed unambiguous identification of active surging phases of Boydell, Sjögren, Edgeworth, Bombardier, and Drygalski glaciers. This discovery calls for a reconsideration of former hypotheses about the stabilizing role of ice shelves.
Citation: Hernán De Angelis, Pedro Skvarca, Science 07 Mar 2003: Vol. 299, Issue 5612, pp. 1560-1562, DOI: 10.1126/science.1077987.

Risk Estimation of Collapse of the West Antarctic Ice Sheet – Vaughan & Spouge (2002) [FULL TEXT]
Abstract: Complete collapse of the West Antarctic Ice Sheet (WAIS) would raise global sea level by around 5 m, but whether collapse is likely, or even possible, has been `glaciology’s grand unsolved problem’ for more than two decades. Collapse of WAIS may result from readjustments continuing since the last glacial maximum, or more recent climate change, but it is also possible that collapse will result from internal flow instabilities, or not occur at all in the present inter-glacial. Such complexity led the Intergovernmental Panel on Climate Change to conclude in its Second Assessment Report that `estimating the likelihood of a collapse during the next century is not yet possible’. However, a refusal by scientists to estimate the risk leaves policy-makers with no sound scientific basis on which to respond to legitimate public concerns. Here we present a discussion of the likelihood of WAIS-collapse, drawing input from an interdisciplinary panel of experts. The results help to summarise the state of scientific knowledge and uncertainty. While the overall opinion of the panel was that WAIS most likely will not collapse in the next few centuries, their uncertainty retains a 5% probability of WAIS causing sea level rise at least 10 mm/year within 200 years. Since this uncertainty reflects both the unpredictability of the physical system and the scientific uncertainty, it will undoubtedly change as a better understanding is established.
Citation: David G. Vaughan, John R. Spouge, Climatic Change, January 2002, Volume 52, Issue 1, pp 65-91, DOI: 10.1023/A:1013038920600.

No evidence for a Pleistocene collapse of the West Antarctic Ice Sheet from continental margin sediments recovered in the Amundsen Sea – Hillenbrand et al. (2002)
Abstract: Records of glaciomarine deposition recovered from the West Antarctic continental margin in the Amundsen Sea allow the reconstruction of the behaviour of the West Antarctic Ice Sheet (WAIS) in response to the natural climatic changes of the last 1.8 million years. Contents of gravel-sized and lithogenic components represent the input and redeposition of glaciogenic debris, whereas variations in the proportions of the calcareous sediment fraction reflect palaeoproductivity changes. All proxies, which are regarded as sensitive to a WAIS collapse, changed markedly during the global climatic cycles, but do not confirm a complete disintegration of the WAIS during the Pleistocene.
Citation: Claus-Dieter Hillenbrand, Dieter K. Fütterer, Hannes Grobe, Thomas Frederichs, Geo-Marine Letters, July 2002, Volume 22, Issue 2, pp 51-59, DOI: 10.1007/s00367-002-0097-7.

Pleistocene Collapse of the West Antarctic Ice Sheet – Scherer et al. (1998)
Abstract: Some glacial sediment samples recovered from beneath the West Antarctic ice sheet at ice stream B contain Quaternary diatoms and up to 108 atoms of beryllium-10 per gram. Other samples contain no Quaternary diatoms and only background levels of beryllium-10 (less than 106 atoms per gram). The occurrence of young diatoms and high concentrations of beryllium-10 beneath grounded ice indicates that the Ross Embayment was an open marine environment after a late Pleistocene collapse of the marine ice sheet.
Citation: Reed P. Scherer, Ala Aldahan, Slawek Tulaczyk, Göran Possnert, Hermann Engelhardt, Barclay Kamb, Science 03 Jul 1998: Vol. 281, Issue 5373, pp. 82-85, DOI: 10.1126/science.281.5373.82.

Active volcanism beneath the West Antarctic ice sheet and implications for ice-sheet stability – Blankenship et al. (1993)
Abstract: IT is widely understood that the collapse of the West Antarctic ice sheet (WAIS) would cause a global sea level rise of 6 m, yet there continues to be considerable debate about the detailed response of this ice sheet to climate changel–3. Because its bed is grounded well below sea level, the stability of the WAIS may depend on geologically controlled conditions at the base which are independent of climate. In particular, heat supplied to the base of the ice sheet could increase basal melting and thereby trigger ice streaming, by providing the water for a lubricating basal layer of till on which ice streams are thought to slide4,5. Ice streams act to protect the reservoir of slowly moving inland ice from exposure to oceanic degradation, thus enhancing ice-sheet stability. Here we present aerogeophysical evidence for active volcanism and associated elevated heat flow beneath the WAIS near the critical region where ice streaming begins. If this heat flow is indeed controlling ice-stream formation, then penetration of ocean waters inland of the thin hot crust of the active portion of the West Antarctic rift system could lead to the disappearance of ice streams, and possibly trigger a collapse of the inland ice reservoir.
Citation: Donald D. Blankenship, Robin E. Bell, Steven M. Hodge, John M. Brozena, John C. Behrendt, Carol A. Finn, Nature 361, 526 – 529 (11 February 1993); doi:10.1038/361526a0.

Irregular oscillations of the West Antarctic ice sheet – Macayeal (1992) [FULL TEXT]
Abstract: Model simulations of the West Antarctic ice sheet suggest that sporadic, perhaps chaotic, collapse (complete mobilization) of the ice sheet occurred throughout the past one million years. The irregular behaviour is due to the slow equilibration time of the distribution of basal till, which lubricates ice-sheet motion. This nonlinear response means that predictions of future collapse of the ice sheet in response to global warming must take into account its past history, and in particular whether the present basal till distribution predisposes the ice sheet towards rapid change.
Citation: Douglas R. MacAyeal, Nature 359, 29 – 32 (03 September 1992); doi:10.1038/359029a0.

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New research, February 1, 2016

Posted by Ari Jokimäki on February 1, 2016

Some new papers from last few days:

Ocean temperature thresholds for Last Interglacial West Antarctic Ice Sheet collapse

Observational evidence for a negative shortwave cloud feedback in mid to high latitudes

European summer temperatures since Roman times (open access)

Conceptual design of a measurement network of the global change (open access)

Reanalyses and Observations: What’s the difference?

Sea surface temperature climate data record for the North Sea and Baltic Sea

The relationship between climate change and wars waged between nomadic and farming groups from the Western Han Dynasty to the Tang Dynasty period (open access)

Detection of trends in days with thunderstorms in Iran over the past five decades

Influence of climate regime shift on the interdecadal change in tropical cyclone activity over the Pacific Basin during the middle to late 1990s

Coeval fluctuations of the Greenland Ice Sheet and a local glacier, central East Greenland, during late-glacial and early Holocene time

Measurements and Modeling of Contemporary Radiocarbon in the Stratosphere

Can increasing albedo of existing ship wakes reduce climate change?

Emissions and climate forcing from global and Arctic fishing vessels

Shifts in the climate space of temperate cyprinid fishes due to climate change are coupled with altered body sizes and growth rates

Can the richness–climate relationship be explained by systematic variations in how individual species’ ranges relate to climate?

Potential effect of atmospheric warming on grapevine phenology and post-harvest heat accumulation across a range of climates

Evaluating the carbon footprint of Chilean organic blueberry production

Electricity generation mix and economic growth: What role is being played by nuclear sources and carbon dioxide emissions in France?

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New research, January 28, 2016

Posted by Ari Jokimäki on January 28, 2016

Some new papers from last few days:

The Medieval Quiet Period

Neotropical forest expansion during the last glacial period challenges refuge hypothesis

Relative vulnerability to climate change of trees in western North America

Dependence of tropical cyclone intensification rate on sea surface temperature

The updated effective radiative forcing of major anthropogenic aerosols and their effects on global climate at present and in the future

Environmental impacts of high penetration renewable energy scenarios for Europe (open access)

The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

Ecosystem responses to anthropogenic and natural forcing over the last 100?years in the coastal areas of the East China Sea

Climate-change-related regime shifts have altered spatial synchrony of plankton dynamics in the North Sea

Bioclimatic envelope models predict a decrease in tropical forest carbon stocks with climate change in Madagascar

Migratory diversity predicts population declines in birds

Evaluation of downscaled CMIP5 model skill in simulating daily maximum temperature over the southeastern United States

The radiative impact of Nordic anthropogenic black carbon (open access)

Younger Dryas Sea-Level and Meltwater Pulse 1B Recorded in Barbados Reef-Crest Coral Acropora palmata

Global carbon cycle perturbation across the Eocene-Oligocene climate transition (open access)

Human and climatically induced environmental change in the Mediterranean during the Medieval Climate Anomaly and Little Ice Age a case from central Italy

Halogen-based reconstruction of Russian Arctic sea ice area from the Akademii Nauk ice core (Severnaya Zemlya) (open access)

Predictability of the wintertime Arctic Oscillation based on autumn circulation

Climate controls multidecadal variability in U.S. extreme sea level records

Investigating uncertainty in the simulation of the Antarctic ice sheet during the mid-Piacenzian

The Response of the Southern Ocean and Antarctic Sea Ice to Fresh Water from Ice Shelves in an Earth System Model

A coupled model for carbon and radiocarbon evolution during the last deglaciation

Variability in solar irradiance observed at two contrasting Antarctic sites

Phenopix: A R package for image-based vegetation phenology

Securitization in Chinese climate and energy politics

The principal-agent problem and climate change adaptation on public lands

City density and CO2 efficiency

To drill or not to drill? An econometric analysis of US public opinion

Prospects for Swedish acceptance of carbon dioxide storage in the Baltic Sea: Learning from other energy projects

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New research, January 22, 2016

Posted by Ari Jokimäki on January 22, 2016

Some new papers from last few days:

A mental picture of the greenhouse effect (open access)

What would happen to Superstorm Sandy under the influence of a substantially warmer Atlantic Ocean?

High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica

Trends toward an earlier peak of the growing season in Northern Hemisphere mid-latitudes

Forests synchronize their growth in contrasting Eurasian regions in response to climate warming

Observational uncertainty of Arctic sea-ice concentration significantly affects seasonal climate forecasts

A modeling investigation of the Arctic sea ice-atmosphere feedback

Detection and Attribution of Climate Extremes in the Observed Record

Climate system responses to a common emission budget of carbon dioxide

A framework to understand the transient climate response to emissions (open access)

Arctic Air Masses in a Warming World

Twentieth-century sea ice variability in the Weddell Sea and its effect on moisture transport: Evidence from a coastal East Antarctic ice core record

Intercomparison of the Arctic sea ice cover in global ocean–sea ice reanalyses from the ORA-IP project

Characterizing Recent Trends in U.S. Heavy Precipitation

Impact of climate change on precipitation patterns: a comparative approach

Terrestrial biosphere changes over the last 120 kyr (open access)

Sea ice cover in Isfjorden and Hornsund, Svalbard (2000–2014) from remote sensing data (open access)

Comparison of multiple glacier inventories with a new inventory derived from high-resolution ALOS imagery in the Bhutan Himalaya (open access)

Feasibility of improving a priori regional climate model estimates of Greenland ice sheet surface mass loss through assimilation of measured ice surface temperatures (open access)

Ablation from calving and surface melt at lake-terminating Bridge Glacier, British Columbia, 1984–2013 (open access)

Climatic controls and climate proxy potential of Lewis Glacier, Mt. Kenya (open access)

The relative contributions of forest growth and areal expansion to forest biomass carbon (open access)

Response of Northern Hemisphere Midlatitude Circulation to Arctic Amplification in a Simple Atmospheric General Circulation Model

Laurentide Ice Sheet basal temperatures during the last glacial cycle as inferred from borehole data (open access)

Climatic modulation of recent trends in ocean acidification in the California Current System (open access)

Potential future fisheries yields in shelf waters: a model study of the effects of climate change and ocean acidification (open access)

Terrestrial carbon balance in a drier world: the effects of water availability in southwestern North America

Modeling phenological responses of Inner Mongolia grassland species to regional climate change

High fitness costs of climate change-induced camouflage mismatch (open access)

Altitudinal shifts of the native and introduced flora of California in the context of 20th-century warming (open access)

Can we explain the observed methane variability after the Mount Pinatubo eruption? (open access)

Spatial and temporal patterns in Arctic river ice breakup revealed by automated ice detection from MODIS imagery

Paleoclimate of Antarctica reconstructed from clast weathering rind analysis

Spatial scales of temperature and salinity variability estimated from Argo observations (open access)

Sheet, stream, and shelf flow as progressive ice-bed uncoupling: Byrd Glacier, Antarctica and Jakobshavn Isbrae, Greenland (open access)

Sea surface temperature from the new Japanese geostationary meteorological Himawari-8 satellite

Multi-decadal variations in Southern Hemisphere atmospheric 14C: Evidence against a Southern Ocean sink at the end of the Little Ice Age CO2 anomaly

A revised picture of the atmospheric moisture residence time

Substantial proportion of global streamflow less than three months old

How climate metrics affect global mitigation strategies and costs: a multi-model study

Climate change in literature and literary studies: From cli-fi, climate change theater and ecopoetry to ecocriticism and climate change criticism

The CRE – new data and tools for collaborative research in climate and environmental history (open access)

Posted in Adaptation & Mitigation, Climate science, Global warming effects | Leave a Comment »

New research, January 18, 2016

Posted by Ari Jokimäki on January 18, 2016

Some new papers from last few days:

BAMS special supplement: Explaining Extreme Events of 2014 from a Climate Perspective (open access)

Global reconstructions of glacier mass change during the 20th century are consistent (open access)

On the state dependency of the equilibrium climate sensitivity during the last 5 million years (open access)

Continental-scale temperature variability in PMIP3 simulations and PAGES 2k regional temperature reconstructions over the past millennium (open access)

Flowering phenological changes in relation to climate change in Hungary

Climate-vegetation modelling and fossil plant data suggest low atmospheric CO2 in the late Miocene (open access)

Terrestrial biosphere changes over the last 120 kyr (open access)

Radiative Analysis of Global Mean Temperature Trends in the Middle Atmosphere: Effects of Non-Locality and Secondary Absorption Bands

Glacier response to North Atlantic climate variability during the Holocene (open access)

Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration (open access)

Improved Arctic sea ice thickness projections using bias-corrected CMIP5 simulations (open access)

SeaRISE experiments revisited: potential sources of spread in multi-model projections of the Greenland ice sheet (open access)

Millennial changes in North Atlantic oxygen concentrations (open access)

The global warming-induced South Asian High change and its uncertainty

Detection and spatiotemporal analysis of methane ebullition on thermokarst lake ice using high-resolution optical aerial imagery (open access)

Assessing Surface Solar Radiation Fluxes in the CMIP Ensembles

Positive low cloud and dust feedbacks amplify tropical North Atlantic multidecadal oscillation

Climate, CO2 and human population impacts on global wildfire emissions (open access)

The carbon cycle in Mexico: past, present and future of C stocks and fluxes (open access)

Time series construction of summer surface temperatures for Alabama, 1883-2014, and comparisons with tropospheric temperature and climate model simulations

Climate model biases in the width of the tropical belt

A framework for evaluating climate model performance metrics

Comparison between total cloud cover in four reanalysis products and cloud measured by visual observations at U.S. weather stations

Did high Neo-Tethys subduction rates contribute to early Cenozoic warming?

A 14,000-year record of fire, climate, and vegetation from the Bear River Range, southeast Idaho, USA

Biodiversity trends within the Holocene

Tropical and mid-latitude forcing of continental Antarctic temperatures (open access)

Rapid early Holocene sea-level rise in Prydz Bay, East Antarctica

Small glaciers on the Balkan Peninsula: State and changes in the last several years

Satellite-derived changes in the permafrost landscape of central Yakutia, 2000–2011: Wetting, drying, and fires

Warm spells in Northern Europe in relation to atmospheric circulation (open access)

Is robustness really robust? How different definitions of robustness impact decision-making under climate change

Habitat associations drive species vulnerability to climate change in boreal forests

Mechanisms of elevation-dependent warming over the Tibetan plateau in quadrupled CO2 experiments

The effect of tropical cyclones on climate change engagement

Intercomparison of CMIP5 and CMIP3 simulations of the 20th century maximum and minimum temperatures over India and detection of climatic trends

West Nile virus, climate change, and circumpolar vulnerability

Transformational responses to climate change: beyond a systems perspective of social change in mitigation and adaptation (open access)

Climate trends and variability in Ecuador (1966–2011)

Daily precipitation concentration around the world according to several indices

Summer Arctic dipole wind pattern affects the winter Siberian High (open access)

Historical floods in Tabasco and Chiapas during sixteenth–twentieth centuries

Devastation in the Kedarnath (Mandakini) Valley, Garhwal Himalaya, during 16–17 June 2013: a remote sensing and ground-based assessment

Social capital, trust, and adaptation to climate change: Evidence from rural Ethiopia

Russian boreal peatlands dominate the natural European methane budget (open access)

Global assessment of onshore wind power resources considering the distance to urban areas

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New research, January 11, 2016

Posted by Ari Jokimäki on January 11, 2016

Some new papers from last few days:

Rapid Anthropogenic Changes in CO2 and pH in the Atlantic Ocean: 2003-2014

Observing climate change trends in ocean biogeochemistry: when and where (open access)

Butterfly community shifts over 2 centuries

Comparison of carbon balances between continuous-cover and clear-cut forestry in Sweden (open access)

Seed predation and climate impacts on reproductive variation in temperate forests of the southeastern USA

Life in the clouds: are tropical montane cloud forests responding to changes in climate?

Morphological and Dietary Responses of Chipmunks to a Century of Climate Change

A century of human-driven changes in the carbon dioxide concentration of lakes

Time-scales of the European surface air temperature variability: The role of the 7–8 year cycle

Uncertainty Quantification in Climate Modeling and Projection (open access)

Country-specific effects of climate variability on human migration

Why do summer droughts in the Southern Great Plains occur in some La Niña years but not others?

Predictability of winter temperature in China from previous autumn Arctic sea ice (open access)

Variability in crop yields associated with climate anomalies in China over the past three decades

The phenology of winter rye in Poland: an analysis of long-term experimental data (open access)

A decadally-delayed response of the tropical Pacific to Atlantic multidecadal variability

Tornadoes in Europe: Synthesis of the observational datasets

Land cover change and carbon emissions over 100 years in an African biodiversity hotspot

Soil carbon sequestration and biochar as negative emission technologies

The effect of economic growth, oil prices, and the benefits of reactor standardization: Duration of nuclear power plant construction revisited

A multi-dimensional integrated approach to assess flood risks on a coastal city, induced by sea-level rise and storm tides (open access)

Influence of tropical wind on global temperature from months to decades (open access)

How much is the precipitation amount over the tropical coastal region?

Forced and Internal Components of Winter Air Temperature Trends over North America during the Past 50 Years: Mechanisms and Implications

Rapid thinning of the Welsh Ice Cap at 20–19 ka based on 10Be ages

Holocene glacier and climate fluctuations of the maritime ice cap Høgtuvbreen, northern Norway

Climatic variability during the last millennium in Western Iceland from lake sediment records

Integrating solar energy and climate research into science education (open access)

Structural factors driving boreal forest albedo in Finland

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New research, January 5, 2016

Posted by Ari Jokimäki on January 5, 2016

Some new papers from last few days:


Climate-sensitive northern lakes and ponds are critical components of methane release

Biased sampling of methane release from northern lakes: A problem for extrapolation

Increased wintertime CO2 loss as a result of sustained tundra warming

Vascular plants promote ancient peatland carbon loss with climate warming

Carbon fluxes acclimate more strongly to elevated growth temperatures than to elevated CO2 concentrations in a northern conifer

Gradual and sustained carbon dioxide release during Aptian Oceanic Anoxic Event 1a


Quantification of warming climate-induced changes in terrestrial Arctic river ice thickness and phenology

Lake ice phenology from AVHRR data for European lakes: An automated two-step extraction method

Reconciling the discrepancy in ground- and satellite-observed trends in the spring phenology of winter wheat in China from 1993 to 2008

Matching the phenology of Net Ecosystem Exchange and vegetation indices estimated with MODIS and FLUXNET in-situ observations


Shrub-line but not treeline advance matches climate velocity in montane ecosystems of south-central Alaska

Life-stage, not climate change, explains observed tree range shifts

Population variability complicates the accurate detection of climate change responses

Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?

Amplification of El Niño by cloud longwave coupling to atmospheric circulation

Climate change impacts in Sub-Saharan Africa: from physical changes to their social repercussions

Statistical corruption in Beijing’s air quality data has likely ended in 2012

Posted in Adaptation & Mitigation, Climate science, Global warming effects | Leave a Comment »

New research, December 31, 2015

Posted by Ari Jokimäki on December 31, 2015

Some new papers from last few days:

Text-mining the signals of climate change doubt

North by north-west: climate change and directions of density shifts in birds

On the state dependency of the equilibrium climate sensitivity during the last 5 million years (open access)

The need for accurate long-term measurements of water vapor in the upper troposphere and lower stratosphere with global coverage (open access)

Does GRACE see the terrestrial water cycle ‘intensifying’?

Detecting Climate Signals in Precipitation Extremes from TRMM (1998–2013) – Increasing contrast between wet and dry extremes during the “global warming hiatus”

Strengthening relationship between ENSO and western Russian summer surface temperature

Atmospheric conditions in the central Arctic Ocean through the melt seasons of 2012 and 2013: Impact on surface conditions and solar energy deposition into the ice-ocean system

Large Holocene summer temperature oscillations and impact on the peopling of the northeastern Tibetan Plateau

Ice shelf basal melt rates around Antarctica from simulations and observations

Tropical and mid-latitude forcing of continental Antarctic temperatures (open access)

Stratospheric temperature changes during the satellite era

ENSO amplitude changes due to greenhouse warming in CMIP5: Role of mean tropical precipitation in the 20th century

Simulating the role of surface forcing on observed multidecadal upper ocean salinity changes

Antarctic and Southern Ocean surface temperatures in CMIP5 models in the context of the surface energy budget

Climate Change over the Extratropical Southern Hemisphere: The tale from an ensemble of reanalysis datasets

Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration (open access)

Recent changes in glacier velocities and thinning at Novaya Zemlya

Climate change and the distribution and conservation of the world’s highest elevation woodlands in the South American Altiplano

Species and site differences influence climate-shrub growth responses in West Greenland

Inter-annual variations and trends of the urban warming in Tehran

Asymmetry in the response of central Eurasian winter temperature to AMO

Interannual variations of the dominant modes of East Asian winter monsoon and possible links to Arctic sea ice

ENSO influence on the North Atlantic European climate: a non-linear and non-stationary approach

Climate change impacts on a pine stand in Central Siberia

Randomised multichannel singular spectrum analysis of the 20th century climate data (open access)

Does climate change matter for freshwater aquaculture in Bangladesh?

Modeling climate-driven changes in U.S. buildings energy demand

Evaluation of the interdecadal variability of sea surface temperature and sea level in the Pacific in CMIP3 and CMIP5 models

Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community-level responses

Climate-change refugia: shading reef corals by turbidity

The pace of past climate change vs. potential bird distributions and land use in the United States

Long-term trends in precipitation and temperature across the Caribbean

Climate variability, food production shocks, and violent conflict in Sub-Saharan Africa (open access)

Interannual variability in associations between seasonal climate, weather, and extremes: wintertime temperature over the Southwestern United States (open access)

How is adaptation, resilience, and vulnerability research engaging with gender? (open access)

Population limitation in a non-cyclic arctic fox population in a changing climate

Posted in Adaptation & Mitigation, Climate science, Global warming effects | Leave a Comment »


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