A transient climate change simulation with greenhouse gas and aerosol forcing: experimental design and comparison with the instrumental record for the twentieth century

Abstract This paper investigates the impact of aerosol forcing uncertainty on the robustness of estimates of the twentieth-century warming attributable to anthropogenic greenhouse gas emissions. Attribution analyses on three coupled climate models with very different sensitivities and aerosol forcing are carried out. The Third Hadley Centre Coupled Ocean–Atmosphere GCM (HadCM3), Parallel Climate Model (PCM), and GFDL R30 models all provide good simulations of twentieth-century global mean temperature changes when they include both anthropogenic and natural forcings. Such good agreement could result from a fortuitous cancellation of errors, for example, by balancing too much (or too little) greenhouse warming by too much (or too little) aerosol cooling. Despite a very large uncertainty for estimates of the possible range of sulfate aerosol forcing obtained from measurement campaigns, results show that the spatial and temporal nature of observed twentieth-century temperature change constrains the component of past warming attributable to anthropogenic greenhouse gases to be significantly greater (at the 5% level) than the observed warming over the twentieth century. The cooling effects of aerosols are detected in all three models. Both spatial and temporal aspects of observed temperature change are responsible for constraining the relative roles of greenhouse warming and sulfate cooling over the twentieth century. This is because there are distinctive temporal structures in differential warming rates between the hemispheres, between land and ocean, and between mid- and low latitudes. As a result, consistent estimates of warming attributable to greenhouse gas emissions are obtained from all three models, and predictions are relatively robust to the use of more or less sensitive models. The transient climate response following a 1% yr−1 increase in CO2 is estimated to lie between 2.2 and 4 K century−1 (5–95 percentiles).

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Multimodel Multisignal Climate Change Detection at Regional Scale

Journal of Climate ◽

10.1175/jcli3851.1 ◽

2006 ◽

Vol 19 (17) ◽

pp. 4294-4307 ◽

Cited By ~ 50

Author(s):

Xuebin Zhang ◽

Francis W. Zwiers ◽

P. A. Stott

Keyword(s):

Climate Change ◽

Twentieth Century ◽

Greenhouse Gases ◽

Regional Scale ◽

Internal Variability ◽

Anthropogenic Forcing ◽

Internal Climate Variability ◽

Aerosol Forcing ◽

Spatial Domains ◽

Northern Hemispheric

Abstract Using an optimal detection technique and climate change simulations produced with two versions of two GCMs, we have assessed the causes of twentieth-century temperature changes from global to regional scales. Our analysis is conducted in nine spatial domains: 1) the globe; 2) the Northern Hemisphere; four large regions in the Northern Hemispheric midlatitudes covering 30°–70°N including 3) Eurasia, 4) North America, 5) Northern Hemispheric land only, 6) the entire 30°–70°N belt; and three smaller regions over 7) southern Canada, 8) southern Europe, and 9) China. We find that the effect of anthropogenic forcing on climate is clearly detectable at global through regional scales. The effect of combined greenhouse gases and sulfate aerosol forcing is detectable in all nine domains in annual and seasonal mean temperatures observed during the second half of the twentieth century. The effect of greenhouse gases can also be separated from that of sulfate aerosols over this period at continental and regional scales. Uncertainty in these results is larger in the smaller spatial domains. Detection is improved when an ensemble of models is used to estimate the response to anthropogenic forcing and the underlying internal variability of the climate system. Our detection results hold after removal of North Atlantic Oscillation (NAO)-related variability in temperature observations—variability that may or may not be associated with anthropogenic forcing. They also continue to hold when our estimates of natural internal climate variability are doubled.

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Designing Detection and Attribution Simulations for CMIP6 to Optimize the Estimation of Greenhouse Gas–Induced Warming

Journal of Climate ◽

10.1175/jcli-d-14-00691.1 ◽

2015 ◽

Vol 28 (8) ◽

pp. 3435-3438 ◽

Cited By ~ 7

Author(s):

Aurélien Ribes ◽

Nathan P. Gillett ◽

Francis W. Zwiers

Keyword(s):

Climate Change ◽

Greenhouse Gas ◽

Accurate Estimate ◽

Experimental Designs ◽

Climate Response ◽

Transient Climate Response ◽

Detection And Attribution ◽

Aerosol Forcing ◽

Optimal Ensemble ◽

Climate Change Detection

Abstract Climate change detection and attribution studies rely on historical simulations using specified combinations of forcings to quantify the contributions from greenhouse gases and other forcings to observed climate change. In the last CMIP5 exercise, in addition to the so-called all-forcings simulations, which are driven with a combination of anthropogenic and natural forcings, natural forcings–only and greenhouse gas–only simulations were prioritized among other possible experiments. This study addresses the question of optimally designing this set of experiments to estimate the recent greenhouse gas–induced warming, which is highly relevant to the problem of constraining estimates of the transient climate response. Based on Monte Carlo simulations and considering experimental designs with a fixed budget for the number of simulations that modeling centers can perform, the most accurate estimate of historical greenhouse gas–induced warming is obtained with a design using a combination of all-forcings, natural forcings–only, and aerosol forcing–only simulations. An investigation of optimal ensemble sizes, given the constraint on the total number of simulations, indicates that allocating larger ensemble sizes to weaker forcings, such as natural-only, is optimal.

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Aspects of convective activity and extreme events in a transient climate change simulation

Meteorologische Zeitschrift ◽

10.1127/0941-2948/2002/0011-0323 ◽

2002 ◽

Vol 11 (5) ◽

pp. 323-333 ◽

Cited By ~ 6

Author(s):

Sabine Brinkop

Keyword(s):

Climate Change ◽

Extreme Events ◽

Convective Activity ◽

Climate Change Simulation ◽

Transient Climate Change

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Promoting Renewable Energy to Cope with Climate Change—Policy Discourse in Israel

Sustainability ◽

10.3390/su13063170 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3170

Author(s):

Avri Eitan

Keyword(s):

Climate Change ◽

Renewable Energy ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Climate Change Mitigation ◽

Renewable Energies ◽

Mitigation Strategies ◽

Policy Discourse ◽

Policy Makers ◽

Change Mitigation

Evidence shows that global climate change is increasing over time, and requires the adoption of a variety of coping methods. As an alternative for conventional electricity systems, renewable energies are considered to be an important policy tool for reducing greenhouse gas emissions, and therefore, they play an important role in climate change mitigation strategies. Renewable energies, however, may also play a crucial role in climate change adaptation strategies because they can reduce the vulnerability of energy systems to extreme events. The paper examines whether policy-makers in Israel tend to focus on mitigation strategies or on adaptation strategies in renewable energy policy discourse. The results indicate that despite Israel’s minor impact on global greenhouse gas emissions, policy-makers focus more on promoting renewable energies as a climate change mitigation strategy rather than an adaptation strategy. These findings shed light on the important role of international influence—which tends to emphasize mitigation over adaptation—in motivating the domestic policy discourse on renewable energy as a coping method with climate change.

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2 °C vs. High Warming: Transitions to Flood-Generating Mechanisms across Canada

Water ◽

10.3390/w13111494 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1494

Author(s):

Bernardo Teufel ◽

Laxmi Sushama

Keyword(s):

Climate Change ◽

Global Warming ◽

Climate Model ◽

Regional Climate ◽

Adaptation Measures ◽

Relative Contribution ◽

Late 21St Century ◽

Transient Climate Change ◽

Projected Changes ◽

Change Mitigation

Fluvial flooding in Canada is often snowmelt-driven, thus occurs mostly in spring, and has caused billions of dollars in damage in the past decade alone. In a warmer climate, increasing rainfall and changing snowmelt rates could lead to significant shifts in flood-generating mechanisms. Here, projected changes to flood-generating mechanisms in terms of the relative contribution of snowmelt and rainfall are assessed across Canada, based on an ensemble of transient climate change simulations performed using a state-of-the-art regional climate model. Changes to flood-generating mechanisms are assessed for both a late 21st century, high warming (i.e., Representative Concentration Pathway 8.5) scenario, and in a 2 °C global warming context. Under 2 °C of global warming, the relative contribution of snowmelt and rainfall to streamflow peaks is projected to remain close to that of the current climate, despite slightly increased rainfall contribution. In contrast, a high warming scenario leads to widespread increases in rainfall contribution and the emergence of hotspots of change in currently snowmelt-dominated regions across Canada. In addition, several regions in southern Canada would be projected to become rainfall dominated. These contrasting projections highlight the importance of climate change mitigation, as remaining below the 2 °C global warming threshold can avoid large changes over most regions, implying a low likelihood that expensive flood adaptation measures would be necessary.

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Reducing greenhouse gas emissions and adapting agricultural management for climate change in developing countries: providing the basis for action

Global Change Biology ◽

10.1111/gcb.12361 ◽

2013 ◽

Vol 20 (1) ◽

pp. 1-6 ◽

Cited By ~ 35

Author(s):

Stephen M. Ogle ◽

Lydia Olander ◽

Lini Wollenberg ◽

Todd Rosenstock ◽

Francesco Tubiello ◽

...

Keyword(s):

Climate Change ◽

Developing Countries ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Agricultural Management ◽

Gas Emissions

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Structural safety and design under climate change

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1129 ◽

2019 ◽

Author(s):

Pietro Croce ◽

Paolo Formichi ◽

Filippo Landi

Keyword(s):

Climate Change ◽

Greenhouse Gas ◽

Structural Reliability ◽

Greenhouse Gas Emission ◽

Extreme Value ◽

Structural Safety ◽

Climate Projections ◽

Climate Conditions ◽

Impact Of Climate Change ◽

The Impact

The impact of climate change on climatic actions could significantly affect, in the mid-term future, the design of new structures as well as the reliability of existing ones designed in accordance to the provisions of present and past codes. Indeed, current climatic loads are defined under the assumption of stationary climate conditions but climate is not stationary and the current accelerated rate of changes imposes to consider its effects.Increase of greenhouse gas emissions generally induces a global increase of the average temperature, but at local scale, the consequences of this phenomenon could be much more complex and even apparently not coherent with the global trend of main climatic parameters, like for example, temperature, rainfalls, snowfalls and wind velocity.In the paper, a general methodology is presented, aiming to evaluate the impact of climate change on structural design, as the result of variations of characteristic values of the most relevant climatic actions over time. The proposed procedure is based on the analysis of an ensemble of climate projections provided according a medium and a high greenhouse gas emission scenario. Factor of change for extreme value distribution’s parameters and return values are thus estimated in subsequent time windows providing guidance for adaptation of the current definition of structural loads.The methodology is illustrated together with the outcomes obtained for snow, wind and thermal actions in Italy. Finally, starting from the estimated changes in extreme value parameters, the influence on the long-term structural reliability can be investigated comparing the resulting time dependent reliability with the reference reliability levels adopted in modern Structural codes.

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