Effects of changing climate on the hydrology of a boreal catchment and lake DOC : probabilistic assessment of a dynamic model chain

Peer reviewe

An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces

IRS2 TEAM:Alfredo Rodríguez(1), Ignacio J. Lorite(3), Fulu Tao(4), Nina Pirttioja(5), Stefan Fronzek(5), Taru Palosuo(4), Timothy R. Carter(5), Marco Bindi(2), Jukka G Höhn(4), Kurt Christian Kersebaum(6), Miroslav Trnka(7,8),Holger Hoffmann(9), Piotr Baranowski(10), Samuel Buis(11), Davide Cammarano(12), Yi Chen(13,4), Paola Deligios(14), Petr Hlavinka(7,8), Frantisek Jurecka(7,8), Jaromir Krzyszczak(10), Marcos Lana(6), Julien Minet(15), Manuel Montesino(16), Claas Nendel(6), John Porter(16), Jaime Recio(1), Françoise Ruget(11), Alberto Sanz(1), Zacharias Steinmetz(17,18), Pierre Stratonovitch(19), Iwan Supit(20), Domenico Ventrella(21), Allard de Wit(20) and Reimund P. Rötter(4).An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces . International Crop Modelling Symposiu

Using impact response surfaces to analyse the likelihood of impacts on crop yield under a changing climate.

Most studies of future climate change impacts rely on estimates based on a limited set of projections of future climate. This way, it is not possible to determine whether one estimate is more or less likely than another. However, if future climate outcomes can be expressed probabilistically, this makes it possible to express impacts in terms of likelihoods, as demonstrated in this study.The approach involves overlaying joint probability density functions (pdfs) that describe uncertainties in projections of temperature and precipitation change over future time periods (using RCP-based climate model simulations) with impact response surfaces (IRSs). The IRS shows the modelled sensitivity of crop yield across a wide range of systematic changes in the same climate variables relative to the baseline (1981-2010). The likelihood of falling short of a target yield threshold is then calculated by integrating across the area of the pdf where yields are below the threshold. The WOFOST crop model was run for a locally grown cultivar of spring barley in south-west Finland assuming contrasting clay loam and sandy soils. IRSs were constructed for seven future CO2 concentrations representing time periods during the 21st century, so that the time-evolution of impact likelihoods with respect to mean yield levels and reliability can be presented. The effectiveness of adaptation options was demonstrated with simulations for cultivars with different development rates.The approach is an efficient way to summarise results and communicate them to a wider audience. Results indicate that the CO2 fertilisation effect counteracts the decline in yields with higher temperatures, and that a future switch to later maturing cultivars would lower the likelihood of a shortfall and produce higher yields

Probabilistic assessment of crop adaptation options under a changing climate

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Temperature and precipitation effects on wheat yield across a European transect: a crop model ensemble analysis using impact response surfaces

This study explored the utility of the impact response surface (IRS) approach for investigating model ensemble crop yield responses under a large range of changes in climate. IRSs of spring and winter wheat Triticum aestivum yields were constructed from a 26-member ensemble of process-based crop simulation models for sites in Finland, Germany and Spain across a latitudinal transect. The sensitivity of modelled yield to systematic increments of changes in temperature (-2 to +9°C) and precipitation (-50 to +50%) was tested by modifying values of baseline (1981 to 2010) daily weather, with CO2 concentration fixed at 360 ppm. The IRS approach offers an effective method of portraying model behaviour under changing climate as well as advantages for analysing, comparing and presenting results from multi-model ensemble simulations. Though individual model behaviour occasionally departed markedly from the average, ensemble median responses across sites and crop varieties indicated that yields decline with higher temperatures and decreased precipitation and increase with higher precipitation. Across the uncertainty ranges defined for the IRSs, yields were more sensitive to temperature than precipitation changes at the Finnish site while sensitivities were mixed at the German and Spanish sites. Precipitation effects diminished under higher temperature changes. While the bivariate and multi-model characteristics of the analysis impose some limits to interpretation, the IRS approach nonetheless provides additional insights into sensitivities to inter-model and inter-annual variability. Taken together, these sensitivities may help to pinpoint processes such as heat stress, vernalisation or drought effects requiring refinement in future model development

What would happen to barley production in Finland if global warming exceeded 4 °C? A model-based assessment

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