scholarly journals Rates of global temperature change during the past millennium

2011 ◽  
Vol 7 (4) ◽  
pp. 2341-2354
Author(s):  
C. Shen ◽  
W.-C. Wang ◽  
G. Zeng ◽  
Y. Peng ◽  
Y. Xu
Keyword(s):  
Greenhouse Gases ◽  
Surface Temperature ◽  
Temperature Change ◽  
20Th Century ◽  
Time Scale ◽  
Climate Model ◽  
Global Climate Model ◽  
Surface Temperature Change ◽  
The Past ◽  
Past Millennium

Abstract. We examine the characteristics (amplitude and phase) of the temporal variation in the rates of global-mean surface temperature change during the past millennium. The study was conducted by applying 20-, 30-, and 50-yr sliding windows to the observations of recent century and reconstructions of earlier times. The analysis focuses on the characteristics of the 20th century within the context of the millennium as well as their sensitivity to the low frequency variability of sea surface temperature (SST) and time scales. On 20-yr time scale, comparable rates to that of the 20th century in both amplitude and phase occur in earlier nine centuries. The peak in the amplitude of rates in the 20th century on 30-yr time scale, although is not the largest during the past millennium, but is the most persistent. On 50-yr time scale, the 20th century warming rates are the highest and the most persistent during the past millennium. The results also indicate that although the SST variability does not affect much the amplitude of the rates, but the phases is quite different, thus highlighting the importance of the role of oceans in affecting the rates. We also analyzed the characteristics from global climate model (1000–1999 AD) simulations with different climate (solar, volcanic, and greenhouse gases) forcing. Except for the one driven by the solar forcing, other forcing simulates similar amplitudes as the observed ones. However, only greenhouse gases (GHG) forcing can reproduce the persistent high warming rates of the 20th century.

scholarly journals Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011)

2012 ◽  
Vol 12 (1) ◽  
pp. 2853-2861 ◽  
Author(s):  
M. Previdi ◽  
L. M. Polvani
Keyword(s):  
Greenhouse Gases ◽  
Surface Temperature ◽  
Temperature Change ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Temperature Response ◽  
First Century ◽  
Tropospheric Temperature ◽  
Surface Temperature Change ◽  
Twenty First Century

Abstract. Stratospheric ozone recovery is expected to figure prominently in twenty-first century climate change. In a recent paper, Hu et al. (2011) argue that one impact of ozone recovery will be to enhance the warming of the surface-troposphere system produced by increases in well-mixed greenhouse gases; furthermore, this enhanced warming would be strongest in the Northern Hemisphere, which is surprising since previous studies have consistently shown the effects of stratospheric ozone changes to be most pronounced in the Southern Hemisphere. Hu et al. (2011) base their claims largely on differences in the simulated temperature change between two groups of IPCC climate models, one group which included stratospheric ozone recovery in its twenty-first century simulations and a second group which did not. Both groups of models were forced with the same increases in well-mixed greenhouse gases according to the A1B emissions scenario. In the current work, we compare the surface temperature responses of the same two groups of models in a different experiment in which atmospheric CO2 was increased by 1% per year until doubling. We find remarkably similar differences in the simulated surface temperature change between the two sets of models as Hu et al. (2011) found for the A1B experiment, suggesting that the enhanced warming which they attribute to stratospheric ozone recovery is actually a reflection of different responses of the two model groups to greenhouse gas forcing.

scholarly journals FAIR v1.1: A simple emissions-based impulse response and carbon cycle model

2017 ◽  
Author(s):  
Christopher J. Smith ◽  
Piers M. Forster ◽  
Myles Allen ◽  
Nicholas Leach ◽  
Richard J. Millar ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Temperature Change ◽  
Radiative Forcing ◽  
Climate Model ◽  
Future Climate Change ◽  
Climate Response ◽  
Rcp Scenarios ◽  
Transient Climate Response ◽  
Surface Temperature Change ◽  
Future Projections

Abstract. Simple climate models can be valuable if they are able to replicate aspects of complex fully coupled earth system models. Larger ensembles can be produced, enabling a probabilistic view of future climate change. A simple emissions-based climate model, FAIR, is presented which calculates atmospheric concentrations of greenhouse gases and effective radiative forcing (ERF) from greenhouse gases, aerosols, ozone precursors and other agents. The ERFs are integrated into global mean surface temperature change. Model runs are constrained to observed temperature change from 1880 to 2016 and produce a range of future projections under the Representative Concentration Pathway (RCP) scenarios. For the historical period the ERF time series in FAIR emulates the results in the IPCC Fifth Assessment Report (AR5), whereas for RCP historical and future scenarios, the greenhouse gas concentrations in FAIR closely track the observations and projections in the RCPs. The constrained estimates of equilibrium climate sensitivity (ECS) of 2.79 (1.97 to 4.08) K, transient climate response (TCR) of 1.47 (1.03 to 2.23) K and transient climate response to cumulative CO2 emissions (TCRE) of 1.43 (1.01 to 2.16) K (1000 GtC)−1 (median and 5–95 % credible intervals) are in good agreement, with tighter uncertainty bounds, than AR5 (1.5 to 4.5 K, 1.0 to 2.5 K, and 0.8 to 2.5 K respectively). The ranges of future projections of temperature and ranges of estimates of ECS, TCR and TCRE are moderately sensitive to the historical temperature dataset used to constrain, prior distributions of ECS/TCR parameters, aerosol radiative forcing relationship and ERF from a doubling of CO2. Taking these sensitivities into account, there is no evidence to suggest that the median and credible range of observationally constrained TCR or ECS differ from climate model-derived estimates. However, the range of temperature projections under the RCP scenarios for 2081–2100 in the constrained FAIR model ensemble are lower than the emissions-based estimates reported in AR5.

scholarly journals The 15th century Arctic warming in coupled model simulations with data assimilation

2009 ◽  
Vol 5 (3) ◽  
pp. 389-401 ◽  
Author(s):  
E. Crespin ◽  
H. Goosse ◽  
T. Fichefet ◽  
M. E. Mann
Keyword(s):  
Data Assimilation ◽  
Surface Temperature ◽  
Climate Model ◽  
Three Dimensional ◽  
Coupled Model ◽  
Internal Variability ◽  
The Arctic ◽  
Arctic Warming ◽  
The Past ◽  
Past Millennium

Abstract. An ensemble of simulations of the climate of the past millennium conducted with a three-dimensional climate model of intermediate complexity are constrained to follow temperature histories obtained from a recent compilation of well-calibrated surface temperature proxies using a simple data assimilation technique. Those simulations provide a reconstruction of the climate of the Arctic that is compatible with the model physics, the forcing applied and the proxy records. Available observational data, proxy-based reconstructions and our model results suggest that the Arctic climate is characterized by substantial variations in surface temperature over the past millennium. Though the most recent decades are likely to be the warmest of the past millennium, we find evidence for substantial past warming episodes in the Arctic. In particular, our model reconstructions show a prominent warm event during the period 1470–1520. This warm period is likely related to the internal variability of the climate system, that is the variability present in the absence of any change in external forcing. We examine the roles of competing mechanisms that could potentially produce this anomaly. This study leads us to conclude that changes in atmospheric circulation, through enhanced southwesterly winds towards northern Europe, Siberia and Canada, are likely the main cause of the late 15th/early 16th century Arctic warming.

scholarly journals Testing the consistency between changes in simulated climate and Alpine glacier length over the past millennium

2018 ◽  
Author(s):  
Hugues Goosse ◽  
Pierre-Yves Barriat ◽  
Quentin Dalaiden ◽  
François Klein ◽  
Ben Marzeion ◽  
...  
Keyword(s):  
20Th Century ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Models ◽  
Late 20Th Century ◽  
The Past ◽  
Simulated Climate ◽  
Glacier Length ◽  
Past Millennium

Abstract. It is standard to compare climate model results covering the past millennium and reconstructions based on various archives in order to test the ability of models to reproduce the observed climate variability. Up to now, glacier length fluctuations have not been used systematically in this framework even though they offer information on multi-decadal to centennial variations complementary to other records. One reason is that glacier length depends on several complex factors and so cannot be directly linked to the simulated climate. However, climate model skill can be measured by comparing the glacier length computed by a glacier model driven by simulated temperature and precipitation to observed glacier length variations. This is done here using the version 1.0 of Open Global Glacier Model (OGGM) forced by fields derived from a range of simulations performed with global climate models over the past millennium. The glacier model is applied to a set of Alpine glaciers for which observations cover at least the 20th century. The observed glacier length fluctuations are generally well within the range of the simulations driven by the various climate model results, showing a general consistency with this ensemble of simulations. Sensitivity experiments indicate that the results are much more sensitive to the simulated climate than to OGGM parameters. This confirms that the simulations of glacier length can be used to evaluate the climate model performance, in particular the summer temperatures that largely control the glacier changes in our region of interest. Simulated glacier length is strongly influenced by the internal variability of the system, putting limitations on the model-data comparison for some variables like the trends over the 20th century in the Alps. Nevertheless, comparison of glacier length fluctuations on longer timescales, for instance between the 18th century and the late 20th century, appear less influenced by the natural variability and indicate clear differences in the behaviour of the various climate models.

scholarly journals Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011)

2012 ◽  
Vol 12 (11) ◽  
pp. 4893-4896 ◽  
Author(s):  
M. Previdi ◽  
L. M. Polvani
Keyword(s):  
Greenhouse Gases ◽  
Surface Temperature ◽  
Temperature Change ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Temperature Response ◽  
First Century ◽  
Tropospheric Temperature ◽  
Surface Temperature Change ◽  
Twenty First Century

Abstract. Stratospheric ozone recovery is expected to figure prominently in twenty-first century climate change. In a recent paper, Hu et al. (2011) argue that one impact of ozone recovery will be to enhance the warming of the surface-troposphere system produced by increases in well-mixed greenhouse gases. Furthermore, this enhanced warming would be strongest in the Northern Hemisphere, which is surprising since previous studies have consistently shown the effects of stratospheric ozone changes to be most pronounced in the Southern Hemisphere. Hu et al. (2011) base their claims largely on differences in the simulated temperature change between two groups of CMIP3 (Coupled Model Intercomparison Project 3) climate models, one group which included stratospheric ozone recovery in its twenty-first century simulations and a second group which did not. Both groups of models were forced with the same increases in well-mixed greenhouse gases according to the A1B emissions scenario. In the current work, we compare the surface temperature responses of the same two groups of models in a different experiment in which atmospheric CO2 was increased by 1% per year until doubling. We find remarkably similar differences in the simulated surface temperature change between the two sets of models as Hu et al. (2011) found for the A1B experiment, suggesting that the enhanced warming which they attribute to stratospheric ozone recovery is actually a reflection of different responses of the two model groups to greenhouse gas forcing.

scholarly journals Testing the consistency between changes in simulated climate and Alpine glacier length over the past millennium

2018 ◽  
Vol 14 (8) ◽  
pp. 1119-1133 ◽  
Author(s):  
Hugues Goosse ◽  
Pierre-Yves Barriat ◽  
Quentin Dalaiden ◽  
François Klein ◽  
Ben Marzeion ◽  
...  
Keyword(s):  
20Th Century ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Models ◽  
Late 20Th Century ◽  
The Past ◽  
Simulated Climate ◽  
Glacier Length ◽  
Past Millennium

Abstract. It is standard to compare climate model results covering the past millennium and reconstructions based on various archives in order to test the ability of models to reproduce the observed climate variability. Up to now, glacier length fluctuations have not been used systematically in this framework even though they offer information on multi-decadal to centennial variations complementary to other records. One reason is that glacier length depends on several complex factors and so cannot be directly linked to the simulated climate. However, climate model skill can be measured by comparing the glacier length computed by a glacier model driven by simulated temperature and precipitation to observed glacier length variations. This is done here using the version 1.0 of the Open Global Glacier Model (OGGM) forced by fields derived from a range of simulations performed with global climate models over the past millennium. The glacier model is applied to a set of Alpine glaciers for which observations cover at least the 20th century. The observed glacier length fluctuations are generally well within the range of the simulations driven by the various climate model results, showing a general consistency with this ensemble of simulations. Sensitivity experiments indicate that the results are much more sensitive to the simulated climate than to OGGM parameters. This confirms that the simulations of glacier length can be used to evaluate the climate model performance, in particular the simulated summer temperatures that largely control the glacier changes in our region of interest. Simulated glacier length is strongly influenced by the internal variability in the system, putting limitations on the model–data comparison for some variables like the trends over the 20th century in the Alps. Nevertheless, comparison of glacier length fluctuations on longer timescales, for instance between the 18th century and the late 20th century, appear less influenced by the natural variability and indicate clear differences in the behaviour of the various climate models.

scholarly journals Potential causes of 15th century Arctic warming using coupled model simulations with data assimilation

2009 ◽  
Vol 5 (1) ◽  
pp. 1-27 ◽  
Author(s):  
E. Crespin ◽  
H. Goosse ◽  
T. Fichefet ◽  
M. E. Mann
Keyword(s):  
Data Assimilation ◽  
Surface Temperature ◽  
Climate Model ◽  
Coupled Model ◽  
Internal Variability ◽  
The Arctic ◽  
Arctic Warming ◽  
The Past ◽  
15Th Century ◽  
Past Millennium

Abstract. An ensemble of simulations of the climate of the past millennium using a three-dimensional climate model of intermediate complexity are constrained to follow temperature histories obtained from a recent compilation of well-calibrated surface temperature proxies using a simple data assimilation technique. Those simulations provide a reconstruction of the climate of the Arctic that is compatible with model physics, the forcing applied and the proxy records. Available observational data, proxy-based reconstructions and our model results suggest that the Arctic climate is characterized by substantial variations in surface temperature over the past millennium. Though the most recent decades are likely to be the warmest of the past millennium, we find evidence for substantial past warming episodes in the Arctic. In particular, our model reconstructions show a particularly warm period at the end of the 15th century. This warm event is likely related to the internal variability of the climate system. We examine the roles of competing mechanisms that could potentially produce this anomaly. These examinations lead us to conclude that changes in atmospheric circulation, through enhanced southwesterly winds towards northern Europe, Siberia and Canada, are likely the main cause of the Arctic warming during the late 15th century.

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