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pmip3:wg:p2f:papers [2017/02/10 15:59]
jules
pmip3:wg:p2f:papers [2017/06/07 09:08] (current)
jules [Future climate forcing potentially without precedent in the last 420 million years]
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  ​~~DISCUSSION~~ ​  ​~~DISCUSSION~~ ​
  
-====== ​Overview of papers ======+====== ​Some papers ​with a focus on using information from the past (or present) to improve predictions of future climate change ​======
  
 Chronological by publication date, most recent first: Chronological by publication date, most recent first:
  
-New additions - details to be added...+==== Future climate forcing potentially without precedent in the last 420 million years ==== 
 +Foster, GL., Royer, DL., & Lunt, D. J., (2017). Future climate forcing potentially without precedent in the last 420 million years. Nature Communications,​ 8, 1–8. http://​doi.org/​10.1038/​ncomms14845 
 +https://​www.nature.com/​articles/​ncomms14845
  
-http://www.clim-past.net/​12/​1591/​2016/​ +Abstract''​The evolution of Earth’s climate on geological timescales is largely driven by variations in the magnitude of total solar irradiance (TSI) and changes in the greenhouse gas content of the atmosphereHere we show that the slow B50 Wm   2 increase in TSI over the last B420 million years (an increase of B9 Wm   2 of radiative forcing) was almost completely negated by a long-term decline in atmospheric CO2This was likely due to the silicate weatheringnegative feedback and the expansion of land plants that together ensured Earth’s long-term habitabilityHumanity’s fossil-fuel use, if unabated, risks taking us, by the middle of the twenty-first century, to values of CO2 not seen since the early Eocene (50 million years ago)If CO2 continues to rise further into the twenty-third century, then the associated large increase in radiative forcing, and how the Earth system would respond, would likely be without geological precedent in the last half a billion years.''​
-http://​www.geosci-model-dev-discuss.net/gmd-2016-220/ +
-http://​people.oregonstate.edu/​~schmita2/​pdf/​M/​muglia15grl.pdf+
  
-Yin Q.Z. and Berger A.2015Interglacial analogues of the Holocene and its natural near futureQuaternary Science Reviews, 120, 28-46+==== The University of Victoria Cloud Feedback Emulator (UVic-CFE): cloud radiative feedbacks in an intermediate complexity model ==== 
 +In review at GMDdoi:10.5194/​gmd-2016-220 
 +http://www.geosci-model-dev-discuss.net/​gmd-2016-220/​ (open access)
  
-Harrison, S.P. and Bartlein, P.J., 2012. Records ​from the pastlessons ​for the future: what the palaeo-record implies about mechanisms ​of global change. In: A. Henderson-Sellers ​and KMcGuffie (Eds), The Future of the World’s Climates. Elsevier, pp. 403-436.+from the abstract: ''​Herewe describe and evaluate a method ​for applying GCM-derived shortwave and longwave cloud feedbacks from 4xCO2 and Last Glacial Maximum experiments to the University of Victoria Earth System Climate Model. The method generally captures ​the spread in top-of-the-atmosphere radiative feedbacks between the original GCMs, which impacts the magnitude ​and spatial distribution of surface temperature changes and climate sensitivityThese results suggest that the method is suitable to incorporate multi-model cloud feedback uncertainties in ensemble simulations with a single intermediate complexity model.''​
  
-HarrisonS.P.BartleinP.J.BrewerS., Prentice, I.C., BoydM., Hessler, I., Holmgren, K., Izumi, K., and Willis, K., 2013. Model benchmarking with glacial and mid-Holocene climates. Climate Dynamics 43: 671-688. DOI 1007/​s00382-013-1922-6 NB Does contain something on climate sensitivity issue, not just benchmarking!+==== Nonlinear climate sensitivity and its implications for future greenhouse warming ==== 
 +Tobias FriedrichAxel TimmermannMichelle TigchelaarOliver Elison Timm and Andrey GanopolskiScience Advances ​ 09 Nov 2016Vol2no11e1501923DOI: 10.1126/sciadv.1501923 http://​advances.sciencemag.org/​content/​2/​11/​e1501923.full 
  
-Izumi, K., Bartlein, P.J. and Harrison, S.P., 2013. Consistent behaviour ​of the climate ​system in response to past and future forcingGeophysical Research Letters 40: 1817-1823doi:10.1002/​grl.50350.+abstract: ''​Global mean surface temperatures are rising in response to anthropogenic greenhouse gas emissionsThe magnitude of this warming at equilibrium for a given radiative forcing—referred to as specific equilibrium climate sensitivity (S)—is still subject to uncertaintiesWe estimate global mean temperature variations ​and S using a 784,000-year-long field reconstruction of sea surface temperatures and a transient paleoclimate model simulation. Our results reveal that is strongly dependent on the climate background state, with significantly larger values attained during warm phasesUsing the Representative Concentration Pathway 8.5 for future greenhouse radiative forcingwe find that the range of paleo-based estimates of Earth’s future warming by 2100 CE overlaps with the upper range of climate ​simulations conducted as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5)Furthermorewe find that within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000 yearsOn the basis of temperature data from eight glacial cycles, our results provide an independent validation of the magnitude of current CMIP5 warming projections.''​
  
-Izumi, K., Bartlein, P.J. and Harrison, S.P., 2014Energy-balance mechanisms underlying consistent large-scale temperature responses in warm and cold climates. Climate Dynamics 443111-3127. DOI 10.1007/s00382-014-2189-2.+==== Could the Pliocene constrain the equilibrium climate sensitivity?​ ==== 
 +JCHargreaves and J. DAnnanClimPast, 12, 1591-1599, 2016 
 +doi:10.5194/cp-12-1591-2016, http://www.clim-past.net/​12/​1591/​2016/​ (open access)
  
-HarrisonS.P., BartleinP.J., Izumi, K., Li, G., Annan, J., Hargreaves, J., Braconnot, P.B., and Kageyama, M., 2015. Implications of evaluation of CMIP5 palaeosimulations ​for climate ​projectionsNature Climate Change 5: 735-743.+Short summary ''​The mid-Pliocene Warm Period3 million years agowas the most recent interval with high greenhouse gasesBy modelling the period with the same models used for future projectionswe can link the past and future climatesHere we use data from the mid-Pliocene to produce a tentative result ​for equilibrium ​climate ​sensitivityWe show that there are considerable uncertainties that strongly influence the result, but we are optimistic that these may be reduced in the next few years.''​
  
 +==== How well do simulated last glacial maximum tropical temperatures constrain equilibrium climate sensitivity?​ ====
 +P.O. Hopcroft and P.J. Valdes, ​ Geophys. Res. Lett., 42, 5533–5539,​ doi:​10.1002/​2015GL064903.
 +http://​onlinelibrary.wiley.com/​doi/​10.1002/​2015GL064903/​full
  
 +''​KEY POINTS: New LGM simulations''​ [CMIP5/​PMIP3] ''​show no tropical temperature to climate sensitivity relation. This is caused by a model complexity, especially due to Earth System components. It is unclear how inferred ECS will change as more model components are included''​
  
 +==== Last glacial maximum constraints on the Earth System model HadGEM2-ES ====
 +P.O. Hopcroft and P.J. Valdes, Clim Dyn (2015) 45: 1657. doi:​10.1007/​s00382-014-2421-0,​ http://​link.springer.com/​article/​10.1007%2Fs00382-014-2421-0
 +
 +From the abstract: ''​HadGEM2-A simulates extreme cooling over northern continents and nearly complete die back of vegetation in Asia, giving a poor representation of the LGM environment compared with reconstructions of surface temperatures and biome distributions. The model also performs significantly worse for the LGM in comparison with its precursor AR4 model HadCM3M2. Detailed analysis shows that the major factor behind the vegetation die off in HadGEM2-A is a subtle change to the temperature dependence of leaf mortality within the phenology model of HadGEM2. This impacts on both snow-vegetation albedo and vegetation dynamics. A new set of parameters is tested for both the pre-industrial and LGM, showing much improved coverage of vegetation in both time periods, including an improved representation of the needle-leaf forest coverage in Siberia for the pre-industrial. The new parameters and the resulting changes in global vegetation distribution strongly impact the simulated loading of mineral dust, an important aerosol for the LGM. The climate response in an abrupt 4× pre-industrial CO2 simulation is also analysed and shows modest regional impacts on surface temperatures across the Boreal zone.''​
 +
 +
 +==== Tropical cyclone genesis potential across palaeoclimates ====
 +Koh, J. H. and Brierley, C. M., Clim. Past, 11, 1433-1451, doi:​10.5194/​cp-11-1433-2015,​ 2015. http://​www.clim-past.net/​11/​1433/​2015/​ (open access)
 +
 +''​The favourability of the mid-Pliocene,​ Last Glacial Maximum (LGM) and mid-Holocene for tropical cyclone formation is investigated in five climate models. During the mid-Pliocene and LGM, changes in carbon dioxide led to sea surface temperature changes throughout the tropics, yet the potential intensity is calculated to be relatively insensitive to these changes. Changes in tropical cyclone genesis potential during the mid-Holocene are found to be asymmetric about the Equator: being reduced in the Northern Hemisphere but enhanced in the Southern Hemisphere. This is clearly driven by the altered seasonal insolation. Nonetheless,​ the enhanced seasonality drove localised changes in genesis potential, by altering the strength of monsoons and shifting the intertropical convergence zone. Trends in future tropical cyclone genesis potential are consistent neither between the five models studied nor with the palaeoclimate results. It is not clear why this should be the case.''​
 +
 +==== Evaluation of CMIP5 palaeo-simulations to improve climate projections. ​ ====
 +Harrison, S.P., Bartlein, P.J., Izumi, K., Li, G., Annan, J., Hargreaves, J., Braconnot, P.B., and Kageyama, M., 2015. Nature Climate Change 5: 735-743.
 +http://​www.nature.com/​nclimate/​journal/​v5/​n8/​full/​nclimate2649.html
 +
 +from abstract: ''​Past climate changes provide a unique opportunity for out-of-sample evaluation of model performance. Palaeo-evaluation has shown that the large-scale changes seen in twenty-first-century projections,​ including enhanced land–sea temperature contrast, latitudinal amplification,​ changes in temperature seasonality and scaling of precipitation with temperature,​ are likely to be realistic. Although models generally simulate changes in large-scale circulation sufficiently well to shift regional climates in the right direction, they often do not predict the correct magnitude of these changes. Differences in performance are only weakly related to modern-day biases or climate sensitivity,​ and more sophisticated models''​ [within the CMIP model ensembles] ''​are not better at simulating climate changes. Although models correctly capture the broad patterns of climate change, improvements are required to produce reliable regional projections.''​
 +
 +
 +==== Glacial Atlantic overturning increased by wind stress in climate models ====
 +Juan Muglia and Andreas Schmittner, 2015,  Geophys. Res. Lett., 42, doi:​10.1002/​2015GL064583,​ http://​people.oregonstate.edu/​~schmita2/​pdf/​M/​muglia15grl.pdf
 +
 +excerpts from conclusions:​ ''​Since LGM wind stress, closure of Bering Strait [Hu et al., 2010], and increased tidal mixing [Schmittner et al., 2015] all tend to increase the strength and depth of the AMOC, a countering effect has to be invoked to reproduce observations of a weaker and shallower overturning during the LGM.” … “It will be an important task for future work to resolve the apparent inconsistency between PMIP models’ LGM circulation and reconstructions.This inconsistency casts doubt on future AMOC projections with these models [e.g., Weaver et al., 2012]. One possible explanation may be that not all PMIP3 models were in equilibrium [Zhang et al., 2013].''​
 +
 +==== Interglacial analogues of the Holocene and its natural near future. ====
 +Yin Q.Z. and Berger A., 2015.  Quaternary Science Reviews, 120, 28-46, http://​www.sciencedirect.com/​science/​article/​pii/​S027737911500150X
 +
 +Highlights:
 +''​•Five warm interglacials are intercompared with both snapshot and transient simulations.
 +•Relationships between astronomical parameters and temperature and precipitation of different latitudes are examined.
 +•Contributions of insolation and CO2 to the intensity and duration of the five interglacials are discussed.
 +•Analogue of the Holocene and its natural future is looked for from the past interglacials.''​
 +
 +==== Energy-balance mechanisms underlying consistent large-scale temperature responses in warm and cold climates. ====
 +Izumi, K., Bartlein, P.J. and Harrison, S.P., 2015.  Climate Dynamics 44: 3111 DOI 10.1007/​s00382-014-2189-2,​ http://​link.springer.com/​article/​10.1007/​s00382-014-2189-2 (open access)
 +
 +''​Climate simulations show consistent large-scale temperature responses including amplified land–ocean contrast, high-latitude/​low-latitude contrast, and changes in seasonality in response to year-round forcing, in both warm and cold climates, and these responses are proportional and nearly linear across multiple climate states. We examine the possibility that a small set of common mechanisms controls these large-scale responses using a simple energy-balance model to decompose the temperature changes shown in multiple lgm and abrupt4 × CO2 simulations from the CMIP5 archive. Changes in the individual components of the energy balance are broadly consistent across the models. Although several components are involved in the overall temperature responses, surface downward clear-sky longwave radiation is the most important component driving land–ocean contrast and high-latitude amplification in both warm and cold climates. Surface albedo also plays a significant role in promoting high-latitude amplification in both climates and in intensifying the land–ocean contrast in the warm climate case. The change in seasonality is a consequence of the changes in land–ocean and high-latitude/​low-latitude contrasts rather than an independent temperature response. This is borne out by the fact that no single component stands out as being the major cause of the change in seasonality,​ and the relative importance of individual components is different in cold and warm climates.''​
 +
 +==== On the state dependency of fast feedback processes in (paleo) climate sensitivity ====
 +A. S. von der Heydt, P. Köhler, R. S. W. van de Wal, H. A. Dijkstra
 +GRL, Volume 41, Issue 18, pages 6484–6492,​ 28 September 2014, DOI: 10.1002/​2014GL061121,​ http://​onlinelibrary.wiley.com/​doi/​10.1002/​2014GL061121/​abstract ​
 +
 +from abstract ''​Here we assess the dependency of the fast feedback processes on the background climate state using data of the last 800 kyr and a box model of the climate system for interpretation. Applying a new method to account for background state dependency, we find Sa=0.61±0.07 K (W m−2)−1(±1σ) using a reconstruction of Last Glacial Maximum (LGM) cooling of −4.0 K and significantly lower climate sensitivity during glacial climates. Due to uncertainties in reconstructing the LGM temperature anomaly, Sa is estimated in the range Sa = 0.54–0.95 K (W m−2)−1.''​
 +
 +==== Consistent large-scale temperature responses in warm and cold climates. ====
 +Izumi, K., Bartlein, P.J. and Harrison, S.P., 2013. , Geophysical Research Letters 40: 1817-1823, doi:​10.1002/​grl.50350,​ http://​onlinelibrary.wiley.com/​doi/​10.1002/​grl.50350/​full
 +
 +Abstract:
 +''​Climate-model simulations of the large-scale temperature responses to increased radiative forcing include enhanced land-sea contrast, stronger response at higher latitudes than in the tropics, and differential responses in warm and cool season climates to uniform forcing. Here we show that these patterns are also characteristic of model simulations of past climates. The differences in the responses over land as opposed to over the ocean, between high and low latitudes, and between summer and winter are remarkably consistent (proportional and nearly linear) across simulations of both cold and warm climates. Similar patterns also appear in historical observations and paleoclimatic reconstructions,​ implying that such responses are characteristic features of the climate system and not simple model artifacts, thereby increasing our confidence in the ability of climate models to correctly simulate different climatic states.''​
 +
 +==== Making sense of palaeoclimate sensitivity ====
 +PALAEOSENS Project Members
 +Nature 491, 683–691 (29 November 2012) doi:​10.1038/​nature11574,​ http://​www.nature.com/​nature/​journal/​v491/​n7426/​abs/​nature11574.html ​
 +
 +from abstract: ''​…to improve intercomparison of palaeoclimate sensitivity estimates in a manner compatible with equilibrium projections for future climate change. Over the past 65 million years, this reveals a climate sensitivity (in K W−1 m2) of 0.3–1.9 or 0.6–1.3 at 95% or 68% probability,​ respectively. The latter implies a warming of 2.2–4.8 K per doubling of atmospheric CO2, which agrees with IPCC estimates.''​
  
 ====Introduction:​ Warm climates of the past—a lesson for the future?==== ====Introduction:​ Warm climates of the past—a lesson for the future?====
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 ''​Using the PMIP2 models and a reconstruction of LGM temperatures (Annan and Hargreaves 2013), to provide a constraint on climate sensitivity. Two different methods for constraining the ensemble were compared, which relied on an apparent correlation between tropical LGM temperature anomaly, and equilibrium climate sensitivity. ''​ ''​Using the PMIP2 models and a reconstruction of LGM temperatures (Annan and Hargreaves 2013), to provide a constraint on climate sensitivity. Two different methods for constraining the ensemble were compared, which relied on an apparent correlation between tropical LGM temperature anomaly, and equilibrium climate sensitivity. ''​
- 
-====Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium ==== 
- 
-**Part 1: Theory**, Sundberg, R., A. Moberg and A. Hind, Clim. Past, 8, 1339-1353, [[http://​www.clim-past.net/​8/​1355/​2012/​cp-8-1355-2012.html|open access]], doi:​10.5194/​cp-8-1339-2012,​ 2012. 
- 
-**Part 2: A pseudo-proxy study addressing the amplitude of solar forcing** A. Hind, A. Moberg, and R. Sundberg, Clim. Past, 8, 1355–1365,​ [[http://​www.clim-past.net/​8/​1355/​2012/,​ doi:​10.5194/​cp-8-1355-2012,​ 2012 |open access]] 
- 
-//keywords : last millennium, test statistics, evaluation, detection / attribution//​ 
- 
-''​Pseudo-proxy experiment to distinguish between high and low solar forcings from model output run over the Last Millennium''​ 
- 
-====Evaluation of climate models using palaeoclimatic data==== 
-Pascale Braconnot, Sandy P. Harrison, Masa Kageyama, Patrick J. Bartlein, Valerie Masson-Delmotte,​ Ayako Abe-Ouchi, Bette Otto-Bliesner & Yan Zhao,   ​Nature Climate Change 2, 417–424, [[http://​www.nature.com/​nclimate/​journal/​v2/​n6/​full/​nclimate1456.html|paywall]],​ doi:​10.1038/​nclimate1456,​ 2012 
- 
-//keywords: review/​prospective,​ PMIP, evaluation // 
- 
-''​Review paper focused on PMIP efforts, displaying relationships between (a) land temperature change and ocean temperature change and (b) global and regional changes and elaborating on how carefullyevaluation ofmodelling of past climates may provide insights / constraints on future climate change. ''​ 
  
 ====Sensitivity of tropical precipitation extremes to climate change====  ​ ====Sensitivity of tropical precipitation extremes to climate change====  ​
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 ''​Abstract:​Assessing the impact of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 kelvin (K) as the best estimate, 2 to 4.5 K as the 66% probability range, and nonzero probabilities for much higher values, the latter implying a small chance of high-impact climate changes that would be difficult to avoid. Here, combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations,​ we estimate a lower median (2.3 K) and reduced uncertainty (1.7 to 2.6 K as the 66% probability range, which can be widened using alternate assumptions or data subsets). Assuming that paleoclimatic constraints apply to the future, as predicted by our model, these results imply a lower probability of imminent extreme climatic change than previously thought.''​ The data, but not the paper may be downlaoded for free from [[http://​people.oregonstate.edu/​~schmita2/#​y2011|Andreas'​ website]]. ''​Abstract:​Assessing the impact of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 kelvin (K) as the best estimate, 2 to 4.5 K as the 66% probability range, and nonzero probabilities for much higher values, the latter implying a small chance of high-impact climate changes that would be difficult to avoid. Here, combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations,​ we estimate a lower median (2.3 K) and reduced uncertainty (1.7 to 2.6 K as the 66% probability range, which can be widened using alternate assumptions or data subsets). Assuming that paleoclimatic constraints apply to the future, as predicted by our model, these results imply a lower probability of imminent extreme climatic change than previously thought.''​ The data, but not the paper may be downlaoded for free from [[http://​people.oregonstate.edu/​~schmita2/#​y2011|Andreas'​ website]].
- 
- 
-====Skill and reliability of climate model ensembles at the Last Glacial Maximum and mid-Holocene==== ​ 
-J. C. Hargreaves, J. D. Annan1, R. Ohgaito, A. Paul, and A. Abe-Ouchi, Clim. Past, 9, 811–823, [[http://​www.clim-past.net/​9/​811/​2013/​|open access]] doi:​10.5194/​cp-9-811-20132013. and **Are paleoclimate model ensembles consistent with the MARGO data synthesis?​** J. C. Hargreaves, A. Paul, R. Ohgaito, A. Abe-Ouchi, and J. D. Annan Clim. Past, 7, 917–933, [[http://​www.clim-past.net/​7/​917/​2011/​|open access]] doi:​10.5194/​cp-7-917-2011,​ 2011 
- 
-//keywords: PMIP, LGM, evaluation, temperature (SAT over land, SST for ocean)// ​ 
- 
-''​Show that PMIP2 and available PMIP3 models are reliable and have skill for air and surface ocean temperatures on broad scales, for the LGM. On the other hand, the MIROC single model ensemble is under-dispersive (a result common for single model ensembles - see Yokohata et al 2010). Additionally the models have no skill and are not reliable for the mid-Holocene interval. ''​ 
  
 ====A probabilistic calibration of climate sensitivity and terrestrial carbon change in GENIE-1==== ​ ====A probabilistic calibration of climate sensitivity and terrestrial carbon change in GENIE-1==== ​
pmip3/wg/p2f/papers.1486742381.txt.gz · Last modified: 2017/02/10 15:59 by jules