Changes to the Canadian Arctic Archipelago Sea Ice and Freshwater Fluxes in the Twenty-First Century under the Intergovernmental Panel on Climate Change A1B Climate Scenario

The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) assessed a range of scenarios of future greenhouse-gas emissions without policies to specifically reduce emissions, and concluded that these would lead to an increase in global mean temperatures of between 1.6°C and 6.9°C by the end of the twenty-first century, relative to pre-industrial. While much political attention is focused on the potential for global warming of 2°C relative to pre-industrial, the AR4 projections clearly suggest that much greater levels of warming are possible by the end of the twenty-first century in the absence of mitigation. The centre of the range of AR4-projected global warming was approximately 4°C. The higher end of the projected warming was associated with the higher emissions scenarios and models, which included stronger carbon-cycle feedbacks. The highest emissions scenario considered in the AR4 (scenario A1FI) was not examined with complex general circulation models (GCMs) in the AR4, and similarly the uncertainties in climate–carbon-cycle feedbacks were not included in the main set of GCMs. Consequently, the projections of warming for A1FI and/or with different strengths of carbon-cycle feedbacks are often not included in a wider discussion of the AR4 conclusions. While it is still too early to say whether any particular scenario is being tracked by current emissions, A1FI is considered to be as plausible as other non-mitigation scenarios and cannot be ruled out. (A1FI is a part of the A1 family of scenarios, with ‘FI’ standing for ‘fossil intensive’. This is sometimes erroneously written as A1F1, with number 1 instead of letter I.) This paper presents simulations of climate change with an ensemble of GCMs driven by the A1FI scenario, and also assesses the implications of carbon-cycle feedbacks for the climate-change projections. Using these GCM projections along with simple climate-model projections, including uncertainties in carbon-cycle feedbacks, and also comparing against other model projections from the IPCC, our best estimate is that the A1FI emissions scenario would lead to a warming of 4°C relative to pre-industrial during the 2070s. If carbon-cycle feedbacks are stronger, which appears less likely but still credible, then 4°C warming could be reached by the early 2060s in projections that are consistent with the IPCC’s ‘likely range’.

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Projection of Global Wave Climate Change toward the End of the Twenty-First Century

Journal of Climate ◽

10.1175/jcli-d-12-00658.1 ◽

2012 ◽

Vol 26 (21) ◽

pp. 8269-8288 ◽

Cited By ~ 75

Author(s):

Alvaro Semedo ◽

Ralf Weisse ◽

Arno Behrens ◽

Andreas Sterl ◽

Lennart Bengtsson ◽

...

Keyword(s):

Climate Change ◽

Climate Model ◽

Global Climate Model ◽

Wave Climate ◽

Ocean Model ◽

First Century ◽

Climate Projections ◽

Moderate Increase ◽

Intergovernmental Panel ◽

Twenty First Century

Abstract Wind-generated waves at the sea surface are of outstanding importance for both their practical relevance in many aspects, such as coastal erosion, protection, or safety of navigation, and for their scientific relevance in modifying fluxes at the air–sea interface. So far, long-term changes in ocean wave climate have been studied mostly from a regional perspective with global dynamical studies emerging only recently. Here a global wave climate study is presented, in which a global wave model [Wave Ocean Model (WAM)] is driven by atmospheric forcing from a global climate model (ECHAM5) for present-day and potential future climate conditions represented by the Intergovernmental Panel for Climate Change (IPCC) A1B emission scenario. It is found that changes in mean and extreme wave climate toward the end of the twenty-first century are small to moderate, with the largest signals being a poleward shift in the annual mean and extreme significant wave heights in the midlatitudes of both hemispheres, more pronounced in the Southern Hemisphere and most likely associated with a corresponding shift in midlatitude storm tracks. These changes are broadly consistent with results from the few studies available so far. The projected changes in the mean wave periods, associated with the changes in the wave climate in the middle to high latitudes, are also shown, revealing a moderate increase in the equatorial eastern side of the ocean basins. This study presents a step forward toward a larger ensemble of global wave climate projections required to better assess robustness and uncertainty of potential future wave climate change.

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Detection of melt onset over the northern Canadian Arctic Archipelago sea ice from RADARSAT, 1997–2014

Remote Sensing of Environment ◽

10.1016/j.rse.2016.03.003 ◽

2016 ◽

Vol 178 ◽

pp. 59-69 ◽

Cited By ~ 19

Author(s):

Mallik Sezan Mahmud ◽

Stephen E.L. Howell ◽

Torsten Geldsetzer ◽

John Yackel

Keyword(s):

Sea Ice ◽

Canadian Arctic ◽

Canadian Arctic Archipelago ◽

Archipelago Sea

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Conceptualising climate change archaeology

Antiquity ◽

10.1017/s0003598x00068472 ◽

2011 ◽

Vol 85 (329) ◽

pp. 1039-1048 ◽

Cited By ~ 48

Author(s):

Robert Van de Noort

Keyword(s):

Climate Change ◽

Nineteenth Century ◽

Significant Contribution ◽

First Century ◽

Archaeological Research ◽

Intergovernmental Panel ◽

Past Climate ◽

Twenty First Century ◽

Past Climate Change ◽

The Impact

Archaeology claims a long tradition, going back to the middle of the nineteenth century, of undertaking both palaeoclimate research and studies on the impact of past climate change on human communities (Trigger 1996: 130–38). Such research ought to be making a significant contribution to modern climate change debates, such as those led by the Intergovernmental Panel on Climate Change (IPCC); but in practice this rarely happens (e.g. McIntosh et al. 2000). This paper will attempt to conceptualise a ‘climate change archaeology’, which is defined here as the contribution of archaeological research to modern climate change debates (cf. Mitchell 2008). Irrespective of whether climate change poses the greatest challenge in the twenty-first century or whether it is just one of many challenges facing humanity (cf. Rowland 2010), the absence of an archaeological voice diminishes the relevance and impact of the debate as a whole.

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Climate Change Projections for the Twenty-First Century and Climate Change Commitment in the CCSM3

Journal of Climate ◽

10.1175/jcli3746.1 ◽

2006 ◽

Vol 19 (11) ◽

pp. 2597-2616 ◽

Cited By ~ 212

Author(s):

Gerald A. Meehl ◽

Warren M. Washington ◽

Benjamin D. Santer ◽

William D. Collins ◽

Julie M. Arblaster ◽

...

Keyword(s):

Climate Change ◽

Twentieth Century ◽

Sea Ice ◽

Sea Level Rise ◽

Sea Level ◽

Climate System ◽

First Century ◽

Change Scenario ◽

Climate System Model ◽

Twenty First Century

Abstract Climate change scenario simulations with the Community Climate System Model version 3 (CCSM3), a global coupled climate model, show that if concentrations of all greenhouse gases (GHGs) could have been stabilized at the year 2000, the climate system would already be committed to 0.4°C more warming by the end of the twenty-first century. Committed sea level rise by 2100 is about an order of magnitude more, percentage-wise, compared to sea level rise simulated in the twentieth century. This increase in the model is produced only by thermal expansion of seawater, and does not take into account melt from ice sheets and glaciers, which could at least double that number. Several tenths of a degree of additional warming occurs in the model for the next 200 yr in the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) B1 and A1B scenarios after stabilization in the year 2100, but with twice as much sea level rise after 100 yr, and doubling yet again in the next 100 yr to 2300. At the end of the twenty-first century, the warming in the tropical Pacific for the A2, A1B, and B1 scenarios resembles an El Niño–like response, likely due to cloud feedbacks in the model as shown in an earlier version. Greatest warming occurs at high northern latitudes and over continents. The monsoon regimes intensify somewhat in the future warmer climate, with decreases of sea level pressure at high latitudes and increases in the subtropics and parts of the midlatitudes. There is a weak summer midlatitude soil moisture drying in this model as documented in previous models. Sea ice distributions in both hemispheres are somewhat overextensive, but with about the right ice thickness at the end of the twentieth century. Future decreases in sea ice with global warming are proportional to the temperature response from the forcing scenarios, with the high forcing scenario, A2, producing an ice-free Arctic in summer by the year 2100.

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Consensus on Twenty-First-Century Rainfall Projections in Climate Models More Widespread than Previously Thought

Journal of Climate ◽

10.1175/jcli-d-11-00354.1 ◽

2012 ◽

Vol 25 (11) ◽

pp. 3792-3809 ◽

Cited By ~ 74

Author(s):

Scott B. Power ◽

François Delage ◽

Robert Colman ◽

Aurel Moise

Keyword(s):

Climate Change ◽

Climate Models ◽

Statistical Significance ◽

First Century ◽

Intergovernmental Panel ◽

Ipcc Report ◽

Projected Change ◽

Twenty First Century ◽

The Impact ◽

Precipitation Projections

Under global warming, increases in precipitation are expected at high latitudes and near major tropical convergence zones in some seasons, while decreases are expected in many subtropical and midlatitude areas in between. In many other areas there is no consensus among models on the sign of the projected change. This is often assumed to indicate that precipitation projections in these regions are highly uncertain. Here, twenty-first century precipitation projections under the Special Report on Emissions Scenarios (SRES) A1B scenario using 24 World Climate Research Programme (WCRP)/Coupled Model Intercomparison Project phase 3 (CMIP3) climate models are examined. In areas with no consensus on the sign of projected change there are extensive subregions where the projected change is “very likely” (i.e., probability > 0.90) to be small (relative to, e.g., the size of interannual variability during the late twentieth century) or zero. The statistical significance of and interrelationships between methods used to identify model consensus on projected change in the 2007 Intergovernmental Panel on Climate Change (IPCC) report are examined, and the impact of interdependency among model projections on statistical significance is investigated. Interdependency among projections is shown to be much weaker than interdependency among simulations of climatology. The results show that there is more widespread consistency among the model projections than one might infer from the 2007 IPCC Fourth Assessment report. This discovery highlights the broader need to identify regions, variables, and phenomena that are expected to be little affected by anthropogenic climate change and to communicate this information to the wider community. This is especially important for projections of climate for the next 1–3 decades.

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Probabilistic climate change predictions applying Bayesian model averaging

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2007.2070 ◽

2007 ◽

Vol 365 (1857) ◽

pp. 2103-2116 ◽

Cited By ~ 50

Author(s):

Seung-Ki Min ◽

Daniel Simonis ◽

Andreas Hense

Keyword(s):

Climate Change ◽

Bayesian Model ◽

Bayes Factor ◽

Bayesian Model Averaging ◽

Model Averaging ◽

Surface Air Temperature ◽

First Century ◽

Intergovernmental Panel ◽

Twenty First Century ◽

Global Mean

This study explores the sensitivity of probabilistic predictions of the twenty-first century surface air temperature (SAT) changes to different multi-model averaging methods using available simulations from the Intergovernmental Panel on Climate Change fourth assessment report. A way of observationally constrained prediction is provided by training multi-model simulations for the second half of the twentieth century with respect to long-term components. The Bayesian model averaging (BMA) produces weighted probability density functions (PDFs) and we compare two methods of estimating weighting factors: Bayes factor and expectation–maximization algorithm. It is shown that Bayesian-weighted PDFs for the global mean SAT changes are characterized by multi-modal structures from the middle of the twenty-first century onward, which are not clearly seen in arithmetic ensemble mean (AEM). This occurs because BMA tends to select a few high-skilled models and down-weight the others. Additionally, Bayesian results exhibit larger means and broader PDFs in the global mean predictions than the unweighted AEM. Multi-modality is more pronounced in the continental analysis using 30-year mean (2070–2099) SATs while there is only a little effect of Bayesian weighting on the 5–95% range. These results indicate that this approach to observationally constrained probabilistic predictions can be highly sensitive to the method of training, particularly for the later half of the twenty-first century, and that a more comprehensive approach combining different regions and/or variables is required.

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Simulating erosion hazard maps under climate change and land use change for the early twenty-first century in northern Iran

Arabian Journal of Geosciences ◽

10.1007/s12517-021-07416-5 ◽

2021 ◽

Vol 14 (15) ◽

Author(s):

Niloofar Rasoolzadeh-Darzi ◽

Hassan Ahmad ◽

Abolfazl Moeini ◽

Baharak Motamedvaziri

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

First Century ◽

Hazard Maps ◽

Northern Iran ◽

Erosion Hazard ◽

Early Twenty ◽

Twenty First Century

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Climate Change Projection in the Twenty-First Century Simulated by NIMS-KMA CMIP6 Model Based on New GHGs Concentration Pathways

Asia-Pacific Journal of Atmospheric Sciences ◽

10.1007/s13143-021-00225-6 ◽

2021 ◽

Author(s):

Hyun Min Sung ◽

Jisun Kim ◽

Sungbo Shim ◽

Jeong-byn Seo ◽

Sang-Hoon Kwon ◽

...

Keyword(s):

Climate Change ◽

Climate Changes ◽

Scientific Information ◽

Earth System Model ◽

First Century ◽

System Model ◽

The Arctic ◽

Earth System ◽

Future Projections ◽

Twenty First Century

AbstractThe National Institute of Meteorological Sciences-Korea Meteorological Administration (NIMS-KMA) has participated in the Coupled Model Inter-comparison Project (CMIP) and provided long-term simulations using the coupled climate model. The NIMS-KMA produces new future projections using the ensemble mean of KMA Advanced Community Earth system model (K-ACE) and UK Earth System Model version1 (UKESM1) simulations to provide scientific information of future climate changes. In this study, we analyze four experiments those conducted following the new shared socioeconomic pathway (SSP) based scenarios to examine projected climate change in the twenty-first century. Present day (PD) simulations show high performance skill in both climate mean and variability, which provide a reliability of the climate models and reduces the uncertainty in response to future forcing. In future projections, global temperature increases from 1.92 °C to 5.20 °C relative to the PD level (1995–2014). Global mean precipitation increases from 5.1% to 10.1% and sea ice extent decreases from 19% to 62% in the Arctic and from 18% to 54% in the Antarctic. In addition, climate changes are accelerating toward the late twenty-first century. Our CMIP6 simulations are released to the public through the Earth System Grid Federation (ESGF) international data sharing portal and are used to support the establishment of the national adaptation plan for climate change in South Korea.

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