Potsdam Institute for Climate Impact Research

About: Potsdam Institute for Climate Impact Research is a facility organization based out in Potsdam, Germany. It is known for research contribution in the topics: Climate change & Global warming. The organization has 1519 authors who have published 5098 publications receiving 367023 citations.

River Floods in the Changing Climate—Observations and Projections

Abstract: River flood damages, worldwide, have increased dynamically in the last few decades, so that it is necessary to interpret this change. River flooding is a complex phenomenon which can be affected by changes coupled to terrestrial, socio-economic and climate systems. The climate track in the observed changes is likely, even if human encroaching into the harm’s way and increase in the damage potential in floodplains can be the dominating factors in many river basins. Increase in intense precipitation has already been observed, with consequences to increasing risk of rain-induced flooding. Projections for the future, based on climate model simulations, indicate increase of flood risks in many areas, globally. Over large areas, a 100-year flood in the control period is projected to become much more frequent in the future time horizon. Despite the fact that the degree of uncertainty in model-based projections is considerable and difficult to quantify, the change in design flood frequency has obvious relevance to flood risk management practice. The number of flood-affected people is projected to increase with the amount of warming. For a 4°C warming the number of flood-affected people is over 2.5 times higher than for a 2°C warming. The present contribution addresses the climate track in an integrated way, tackling issues related to multiple factors, change detection, projections, and adaptation to floods.

Fossil resource and energy security dynamics in conventional and carbon-constrained worlds

Abstract: Fossil resource endowments and the future development of fossil fuel prices are important factors that will critically influence the nature and direction of the global energy system. In this paper we analyze a multi-model ensemble of long-term energy and emissions scenarios that were developed within the framework of the EMF27 integrated assessment model inter-comparison exercise. The diverse nature of these models highlights large uncertainties in the likely development of fossil resource (coal, oil, and natural gas) consumption, trade, and prices over the course of the twenty-first century and under different climate policy frameworks. We explore and explain some of the differences across scenarios and models and compare the scenario results with fossil resource estimates from the literature. A robust finding across the suite of IAMs is that the cumulative fossil fuel consumption foreseen by the models is well within the bounds of estimated recoverable reserves and resources. Hence, fossil resource constraints are, in and of themselves, unlikely to limit future GHG emissions this century. Our analysis also shows that climate mitigation policies could lead to a major reallocation of financial flows between regions, in terms of expenditures on fossil fuels and carbon, and can help to alleviate near-term energy security concerns via the reductions in oil imports and increases in energy system diversity they will help to motivate. Aggressive efforts to promote energy efficiency are, on their own, not likely to lead to markedly greater energy independence, however, contrary to the stated objectives of certain industrialized countries.

The critical role of the routing scheme in simulating peak river discharge in global hydrological models

Abstract: Global hydrological models (GHMs) have been applied to assess global flood hazards, but their capacity to capture the timing and amplitude of peak river discharge—which is crucial in flood simulations—has traditionally not been the focus of examination. Here we evaluate to what degree the choice of river routing scheme affects simulations of peak discharge and may help to provide better agreement with observations. To this end we use runoff and discharge simulations of nine GHMs forced by observational climate data (1971–2010) within the ISIMIP2a project. The runoff simulations were used as input for the global river routing model CaMa-Flood. The simulated daily discharge was compared to the discharge generated by each GHM using its native river routing scheme. For each GHM both versions of simulated discharge were compared to monthly and daily discharge observations from 1701 GRDC stations as a benchmark. CaMa-Flood routing shows a general reduction of peak river discharge and a delay of about two to three weeks in its occurrence, likely induced by the buffering capacity of floodplain reservoirs. For a majority of river basins, discharge produced by CaMa-Flood resulted in a better agreement with observations. In particular, maximum daily discharge was adjusted, with a multi-model averaged reduction in bias over about 2/3 of the analysed basin area. The increase in agreement was obtained in both managed and near-natural basins. Overall, this study demonstrates the importance of routing scheme choice in peak discharge simulation, where CaMa-Flood routing accounts for floodplain storage and backwater effects that are not represented in most GHMs. Our study provides important hints that an explicit parameterisation of these processes may be essential in future impact studies.

Climate change impacts in the Middle East and Northern Africa (MENA) region and their implications for vulnerable population groups

Abstract: The Middle East and North Africa (MENA) region emerges as one of the hot spots for worsening extreme heat, drought and aridity conditions under climate change. A synthesis of peer-reviewed literature from 2010 to date and own modeling work on biophysical impacts of climate change on selected sectors shows that the region is highly affected by present and future climate change. These biophysical impacts paired with other pressures and a lack of resilience in some countries cause high vulnerabilities within these sectors and for social dimensions in the MENA region. The agricultural sector, of which 70 percent is rain-fed, is highly exposed to changing climatic conditions. This is of critical importance as the agriculture sector is the largest employer in many Arab countries and contributes significantly to national economies. Impacts will be high in a 2 °C world, as, e.g., annual water discharge, already critically low, is projected to drop by another 15–45% (75% in a 4 °C world) and unusual heat extremes projected to affect about one-third of the land area with likely consequences for local food production. As a consequence, deteriorating rural livelihoods associated with declining agricultural productivity will continue to contribute to migration flows, often to urban areas as already observed. The region could be heavily challenged by both rising food and water demand given its projected increase in population that may double by 2070. As a result, the regions already substantial import dependency could increase and thus its vulnerability to agricultural impacts well beyond its country borders. A severe and sustained pressure on resources could contribute to further social unrest in the already unstable political environment that currently characterizes parts of the region. While the particular societal responses to such changes are hard to foresee, it is clear that extreme impacts would constitute unprecedented challenges to the social systems affected.