The use of general circulation models in climate impact analysis ? A preliminary study of the impacts of a CO2- induced climatic change on West European agriculture

1985 ◽  
Vol 7 (1) ◽  
pp. 71-93 ◽  
Author(s):  
Benjamin Santer
Keyword(s):  
Climatic Change ◽  
General Circulation ◽  
Impact Analysis ◽  
General Circulation Models ◽  
Climate Impact ◽  
Preliminary Study ◽  
European Agriculture ◽  
West European

scholarly journals Genetic Variation in Abies religiosa for Quantitative Traits and Delineation of Elevational and Climatic Zoning for Maintaining Monarch Butterfly Overwintering Sites in Mexico, considering Climatic Change

2017 ◽  
Vol 66 (1) ◽  
pp. 14-23 ◽  
Author(s):  
M. A. Ortiz-Bibian ◽  
A. Blanco-García ◽  
R. A. Lindig-Cisneros ◽  
M. Gómez-Romero ◽  
D. Castellanos-Acuña ◽  
...  
Keyword(s):  
Climatic Change ◽  
General Circulation ◽  
Final Height ◽  
Danaus Plexippus ◽  
Biosphere Reserve ◽  
General Circulation Models ◽  
Monarch Butterfly ◽  
Frost Damage ◽  
Seed Collection ◽  
Abies Religiosa

AbstractConservation of Abies religiosa (sacred fir) within the Monarch Butterfly Biosphere Reserve (MBBR) in Mexico requires adaptive management to cope with expected climatic change, in order to have healthy trees for Danaus plexippus overwintering sites in the future. Open pollinated seeds from fifteen A. religiosa populations were collected along an elevational gradient (2850-3550 masl; one sampled population every 50 m of elevational difference). Seedlings were evaluated in a common garden test over a period of 30 months. We found significant differences (P < 0.03) among populations in total elongation, final height, date of growth cessation, foliage, stem and total dry weight, as well as frost damage. These differences were strongly associated with the Mean Temperature of the Coldest Month (MTCM; r2= 0.6222, P = 0.0005). Seedlings originating from lower elevation populations grew more but suffered more frost damage than those from higher elevations. Populations differentiate genetically when they are separated by 364 m in elevation. Such differentiation was used to delineate three elevational/climatic zones for seed collection, with limits defined at: 2650 masl or 9.7 °C of MTCM; 3000 masl or 8.5 °C; 3350 masl or 7.3 °C; and 3700 masl or 6.1 °C. Zonification for seedling deployment aiming to match a suitable climate in year 2030 (after projections using an ensemble of 18 General Circulation Models and a Representative Concentration Pathway 6.0 watts/ m2), would have the same MTCM zone limits, but shifted 350 m upwards in elevation. This shift would exceed the highest elevations within the MBBR, necessitating the establishment of A. religiosa stands outside the MBBR, to serve as potential future overwintering sites.

scholarly journals Evaluation of the CMIP5 general circulation models for simulating the precipitation and temperature of the Koshi River Basin in Nepal

2021 ◽  
Author(s):  
Pragya Pradhan ◽  
Sangam Shrestha ◽  
S. Mohana Sundaram ◽  
Salvatore G. P. Virdis
Keyword(s):  
River Basin ◽  
General Circulation ◽  
Performance Indicator ◽  
Extreme Temperature ◽  
General Circulation Models ◽  
Climate Impact ◽  
Climate Indices ◽  
Extreme Precipitation Events ◽  
Koshi River Basin ◽  
Precipitation And Temperature

Abstract This study evaluates the performance of 12 different general circulation models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to simulate precipitation and temperature in the Koshi River Basin, Nepal. Four statistical performance indicators: correlation coefficient, normalised root-mean-square deviation (NMRSD), absolute NMRSD, and average absolute relative deviation are considered to evaluate the GCMs using historical observations. Seven different climate indices: consecutive dry days, consecutive wet days, cold spell duration index, warm spell duration index, frost days, very wet days, and simple daily intensity index are considered to identify the most suitable models for the basin and future climate impact assessment studies. Weights for each performance indicator are determined using the entropy method, with compromise programming applied to rank the GCMs based on the Euclidian distant technique. The results suggest that CanESM2 and CSIRO-MK3.6.0 are the most suitable for predicting extreme precipitation events, and BCC-CSM 1.1, CanESM2, NorESM1-M, and CNRM-CM5 for extreme temperature events in Himalayan river basins. Overall, IPSL-CM5A-MR, CanESM2, CNRM-CM5, BCC-CSM 1.1, NorESM1-M, and CSIRO-Mk3.6.0 are deemed suitable models for predicting precipitation and temperature in the Koshi River Basin, Nepal.

The use of tracers in modelling the oceanic uptake of carbon dioxide

1988 ◽  
Vol 325 (1583) ◽  
pp. 23-42
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Land Use Change ◽  
Climatic Change ◽  
Diffusion Model ◽  
General Circulation ◽  
General Circulation Models ◽  
Vertical Diffusion ◽  
Mixing Processes ◽  
Change Models

Increasing levels of atmospheric carbon dioxide from the burning of fossil fuels and changes in land use pose a threat of significant global climatic change in the 21st century. Owing to uncertainty in the pre-industrial atmospheric CO 2 concentration and in CO 2 releases from land-use change, direct estimates of the airborne fraction of this man-made CO 2 are not well established. Effort has therefore been devoted to estimating the strengths of the oceanic and biospheric sinks as an alternative route to determining the airborne fraction. This paper reviews the development of oceanic CO 2 -uptake models. One-dimensional box models, with first-order exchange kinetics or vertical diffusion to simulate CO 2 penetration into the deep ocean and calibrated against natural 14 C distributions, appear inadequate. Their uptake is too small to be consistent with the recent atmospheric record and most estimated histories of CO 2 release from land use change. Models incorporating representations of specific oceanic mixing processes important in CO 2 uptake achieve somewhat larger CO 2 uptake, especially when calibrated against ‘ short timescale ’ tracers, such as radiocarbon and tritium derived from bomb tests. Despite this general conclusion, substantial differences between such models remain. A comparison between my two-dimensional advection—diffusion model and Siegenthaler’s outcrop—diffusion model illustrates how the relative importance of air-sea gas exchange rate and rate of ocean mixing in limiting CO 2 uptake depends critically upon modelling assumptions. The failure of most models calibrated with a single oceanic tracer to reproduce well the distribution of other tracers has encouraged the development of multi-box, geographically realistic, models whose circulation and mixing patterns are determined by simultaneous inverse solution of a set of conservation equations for a range of tracers. This technique, when augmented with additional dynamical constraints, probably offers the most promise for advancing CO 2 -uptake modelling while suitable three-dimensional oceanic general circulation models are being developed. The latter, atmospherically driven, models will eventually play a key role in assessing how any future climatic change may feed back on atmospheric CO 2 levels. Feedback could arise either by alteration of the mixing processes responsible for man-made CO 2 uptake, or more fundamentally if changes in the surface-ocean productivity result from changes in circulation-mediated nutrient supply.

scholarly journals Mitigation of Non-CO2 Aviation’s Climate Impact by Changing Cruise Altitudes

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Sigrun Matthes ◽  
Ling Lim ◽  
Ulrike Burkhardt ◽  
Katrin Dahlmann ◽  
Simone Dietmüller ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Temperature Change ◽  
Radiative Forcing ◽  
General Circulation ◽  
General Circulation Models ◽  
Sensitivity Study ◽  
Climate Impact ◽  
Flight Altitude ◽  
Co2 Effects ◽  
The Impact

Aviation is seeking for ways to reduce its climate impact caused by CO2 emissions and non-CO2 effects. Operational measures which change overall flight altitude have the potential to reduce climate impact of individual effects, comprising CO2 but in particular non-CO2 effects. We study the impact of changes of flight altitude, specifically aircraft flying 2000 feet higher and lower, with a set of global models comprising chemistry-transport, chemistry-climate and general circulation models integrating distinct aviation emission inventories representing such alternative flight altitudes, estimating changes in climate impact of aviation by quantifying radiative forcing and induced temperature change. We find in our sensitivity study that flying lower leads to a reduction of radiative forcing of non-CO2 effects together with slightly increased CO2 emissions and impacts, when cruise speed is not modified. Flying higher increases radiative forcing of non-CO2 effects by about 10%, together with a slight decrease of CO2 emissions and impacts. Overall, flying lower decreases aviation-induced temperature change by about 20%, as a decrease of non-CO2 impacts by about 30% dominates over slightly increasing CO2 impacts assuming a sustained emissions scenario. Those estimates are connected with a large but unquantified uncertainty. To improve the understanding of mechanisms controlling the aviation climate impact, we study the geographical distributions of aviation-induced modifications in the atmosphere, together with changes in global radiative forcing and suggest further efforts in order to reduce long standing uncertainties.

Successive Modulation of ENSO to the Future Greenhouse Warming

2008 ◽  
Vol 21 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Yoo-Geun Ham ◽  
In-Sik Kang
Keyword(s):  
General Circulation ◽  
Southern Oscillation ◽  
General Circulation Models ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Delayed Response ◽  
Subsurface Temperature ◽  
Climate System Model ◽  
The Mean ◽  
The Tropical Pacific

Abstract The multidecadal modulation of the El Niño–Southern Oscillation (ENSO) due to greenhouse warming has been analyzed herein by means of diagnostics of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) coupled general circulation models (CGCMs) and the eigenanalysis of a simplified version of an intermediate ENSO model. The response of the global-mean troposphere temperature to increasing greenhouse gases is more likely linear, while the amplitude and period of ENSO fluctuates in a multidecadal time scale. The climate system model outputs suggest that the multidecadal modulation of ENSO is related to the delayed response of the subsurface temperature in the tropical Pacific compared to the response time of the sea surface temperature (SST), which would lead a modulation of the vertical temperature gradient. Furthermore, an eigenanalysis considering only two parameters, the changes in the zonal contrast of the mean background SST and the changes in the vertical contrast between the mean surface and subsurface temperatures in the tropical Pacific, exhibits a good agreement with the CGCM outputs in terms of the multidecadal modulations of the ENSO amplitude and period. In particular, the change in the vertical contrast, that is, change in difference between the subsurface temperature and SST, turns out to be more influential on the ENSO modulation than changes in the mean SST itself.

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