Borbála Gálos

Will dry events occur more often in Hungary in the future

Dry years and dry summers in Hungary have been analyzed using the regional climate model REMO for the time periods 1961–2000 and 2001–2100. Dry periods were determined and classified by intensity, considering modeled and observed precipitation and temperature data. The intensity of dry events was defined according to the negative precipitation deviation and positive temperature deviation from the climate period 1961–90. The proportion of dry years and dry summers is equivalent in the model and observations in the past. On average, the intensity of dry years simulated by the regional climate model REMO is the same as observed, whereas dry summers have more extreme conditions in the model. Based on the results of three IPCC scenario simulations (B1, A1B, A2), the probability of dry events will be higher in the second half of the 21st century. In the scenarios A1B and A2 a dry summer may happen every second year and the consecutive dry periods will last longer. For 2051–2100 the intensity of dry events increases significantly in all scenarios compared to the control period. From the analyzed scenarios B1 has the lowest future greenhouse gas emission rates, so that the smallest changes are also projected for the second half of the 21st century.

Regional characteristics of climate change altering effects of afforestation

Climatic effects of forest cover change have been investigated for Hungary. For the time period 2071–100 we have analyzed whether the climate change signal for summer precipitation and the probability of droughts can be reduced assuming maximal afforestation for the entire country (forests covering all vegetated areas). The biogeophysical effects of land cover change have been assessed using the results of an A1B IPCC-SRES emission scenario from REMO (regional climate model at the Max Planck Institute for Meteorology, Hamburg). The simulation results indicate that afforestation may reduce the projected climate change through higher evapotranspiration and precipitation as well as lower surface temperature for the entire summer period. The magnitude of the feedback of the forest cover increase on precipitation differs among regions. The strongest effects are visible in the northeastern part of the country. Here, half of the projected precipitation decrease can be relieved and the total number of drought events can be reduced, assuming maximal afforestation. Afforestation brings about the smallest climatic effect in the southwestern region, in the area that shows the strongest climate change. The results can help to identify areas where forest cover increase should most effectively support the alleviation of climate change effects.

Case study for the assessment of the biogeophysical effects of a potential afforestation in Europe

BackgroundA regional-scale sensitivity study has been carried out to investigate the climatic effects of forest cover change in Europe. Applying REMO (regional climate model of the Max Planck Institute for Meteorology), the projected temperature and precipitation tendencies have been analysed for summer, based on the results of the A2 IPCC-SRES emission scenario simulation. For the end of the 21st century it has been studied, whether the assumed forest cover increase could reduce the effects of the greenhouse gas concentration change.ResultsBased on the simulation results, biogeophysical effects of the hypothetic potential afforestation may lead to cooler and moister conditions during summer in most parts of the temperate zone. The largest relative effects of forest cover increase can be expected in northern Germany, Poland and Ukraine, which is 15–20% of the climate change signal for temperature and more than 50% for precipitation. In northern Germany and France, potential afforestation may enhance the effects of emission change, resulting in more severe heavy precipitation events. The probability of dry days and warm temperature extremes would decrease.ConclusionsLarge contiguous forest blocks can have distinctive biogeophysical effect on the climate on regional and local scale. In certain regions of the temperate zone, climate change signal due to greenhouse gas emission can be reduced by afforestation due to the dominant evaporative cooling effect during summer. Results of this case study with a hypothetical land cover change can contribute to the assessment of the role of forests in adapting to climate change. Thus they can build an important basis of the future forest policy.

Regional-Scale Assessment of the Climatic Role of Forests Under Future Climate Conditions

Several natural and anthropogenic processes influence the climate of the Earth. Human affect climate through increasing greenhouse gas concentrations, changing aerosol compositions as well as by land surface changes (IPCC, 2007). There are several recent EUprojects carried out in the last decade, to provide high-resolution climate change projections with focus on future climate changes and their impacts in Europe (Christensen et al., 2007; Jacob et al., 2008; van der Linden & Mitchell, 2009). These studies are based on the results of regional climate model simulations driven by different predefined greenhouse gas emission scenarios. The difference between the simulated climatic conditions for the future and for the present time period is the climate change signal. For the 21st century, projected climate change signals for temperature and precipitation show seasonal and spatial differences in Europe and also vary depending on the applied greenhouse gas emission scenario.

The Role of Forests in Mitigating Climate Change - a Case Study for Europe

Abstract - A regional-scale case study has been carried out to assess the possible climatic benefits of forest cover increase in Europe. For the end of the 21st century (2071-2090) it has been investigated, whether the projected climate change could be reduced assuming potential afforestation of the continent. The magnitude of the biogeophysical effects of enhanced forest cover on temperature and precipitation means and extremes have been analyzed relative to the magnitude of the climate change signal applying the regional climate model REMO. The simulation results indicate that in the largest part of the temperate zone potential afforestation may reduce the projected climate change through cooler and moister conditions, thus could contribute to the mitigation of the projected climate change for the entire summer period. The largest relative effect of forest cover increase can be expected in northern Germany, Poland and Ukraine. Here, the projected precipitation decrease could be fully compensated, the temperature increase could be relieved by up to 0.5 °C, and the probability of extremely warm and dry days could be reduced. Results can help to identify the areas, where forest cover increase could be the most effective from climatic point of view. Thus they can build an important basis of the future adaptation strategies and forest policy. Kivonat - Esettanulmány az erdők klímavédelmi szerepének vizsgálatára Európában. Az esettanulmány célja az erdőterület növekedés éghajlati hatásainak, a klímaváltozás mérsékelésében betöltött szerepének számszerűsítése Európában. A REMO regionális klímamodell segítségével vizsgáltuk, hogy a feltételezett potenciális erdőtelepítéssel milyen irányban és mértékben befolyásolhatók a 2071-2090-es időszakra előrevetített hőmérséklet- és csapadéktendenciák. A modellszimulációk eredményei alapján, potenciális erdőtelepítés feltételezésével nyáron a mérsékelt övi területek döntő része hűvösebb, csapadékosabb lehet. A legnagyobb hatás Németország és Lengyelország északi részén, valamint az ukrán-belorusz-orosz határvidéken várható. Ezeken a területeken az erdőtelepítés hatása a hőmérsékletre egy nagyságrenddel kisebb, mint az üvegházgáz koncentráció változásáé. A klímaváltozással járó csapadékmennyiség-csökkenés azonban szinte teljes egészében kiegyenlíthető lenne, és a szélsőségesen meleg és száraz napok gyakorisága csökkenhet. Az erdő-klíma kölcsönhatások számszerűsítése nem csak az erdők klímavédelmi szerepéről ad információt, hanem az éghajlatváltozás következményeinek megelőzését, enyhítését célzó stratégiák alapja is lehet.

A new decision support system to analyse the impacts of climate change on the Hungarian forestry and agricultural sectors

ABSTRACT In this paper, a novel decision support system (DSS) will be introduced, based on geospatial data analyses that we developed for the Hungarian forestry and agricultural sectors. This work was part of a larger research project, whose goal is to evaluate the impacts of projected climate change on forestry and agriculture and to identify potential adaptation options. The proposed DSS integrates various environmental coverages, including topography, vegetation, climate, soils, and hydrology. It also processes time-series data such as meteorological variables. The novelty of the system is its geospatial and geostatistical capability to map species spatial and climate space distribution and yield data using machine learning techniques (Maximum likelihood and Fuzzy logic). The DSS can generate projections, as well as sensitivity and risk assessments, and in this way, it can help to develop adaptation and mitigation strategies. The web-based implementation of the DSS allows decision-makers to directly interact with both current and projected geoinformation. The mechanics and the benefits of the DSS will be demonstrated on a Hungarian county where the system was first implemented as a prototype.

Modelling the Potential Distribution of Three Climate Zonal Tree Species for Present and Future Climate in Hungary

Abstract The potential distribution and composition rate of beech, sessile oak and Turkey oak were investigated for present and future climates (2036-2065 and 2071-2100) in Hungary. Membership functions were defined using the current composition rate (percentage of cover in forest compartments) of the tree species and the long-term climate expressed by the Ellenberg quotient to model the present and future tree species distribution and composition rate. The simulation results using the regional climate model REMO showed significant decline of beech and sessile oak in Hungary during the 21st century. By the middle of the century only about 35% of the present beech and 75% of the sessile oak stands will remain above their current potential distribution limit. By the end of the century beech forests may almost disappear from Hungary and sessile oak will also be found only along the Southwest border and in higher mountain regions. On the contrary the present occurrences of Turkey oak will be almost entirely preserved during the century however its distribution area will shift to the current sessile oak habitats. Kivonat Három klímazonális fafaj hazai potenciális elterjedésének modellezése jelenlegi és jövőbeni klímában. A bükk, a kocsánytalan tölgy és a csertölgy potenciális elterjedését és elegyarányát vizsgáltuk Magyarországon a jelenlegi és a jövőben (2036-2065 és 2071-2100) várható klimatikus körülmények között. A vizsgált fafajok jelenlegi elegyarányának (az erdőrészletben elfoglalt terület aránya, %) és a klímának (az Ellenberg index-el kifejezve) az összefüggését használtuk a fafajok elterjedésének modellezéséhez. A REMO regionális klímamodellel történt szimuláció a bükk és a kocsánytalan tölgy elterjedési területének és elegyarányának jelentős csökkenését mutatta a 21. század folyamán. A század közepére a jelenlegi bükk állományok 35%-a, a kocsánytalan tölgy állományok 75%-a maradna a jelenlegi alsó elterjedési határuk felett. A század végére a bükk szinte teljesen eltűnhet Magyarország területéről és a kocsánytalan tölgy is a magasabb hegyvidékekre és a délnyugati határ menti területre húzódhat vissza. Ellenben a csertölgy jelenlegi állományait várhatóan nem érinti számottevően a klímaváltozás, viszont az elterjedési területe a jelenlegi kocsánytalan tölgyes állományok helyét foglalhatja el.