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.

Systematic Multiscale Models for the Tropics

Abstract: Systematic multi-scale perturbation theory is utilized to develop self-consistent simplified model equations for the interaction across multiple spatial and/or temporal scales in the tropics. One of these models involves simplified equations for intraseasonal planetary equatorial synoptic scale dynamics (IPESD). This model includes the self-consistent quasi-linear interaction of synoptic scale generalized steady Matsuno-Webster-Gill models with planetary scale dynamics of equatorial long waves. These new models have the potential for providing self-consistent prognostic and diagnostic models for the intraseasonal tropical oscillation. Other applications of the systematic approach reveal three different balanced weak temperature gradient (WTG) approximations for the tropics with different regimes of validity in space and time: a synoptic equatorial scale WTG (SEWTG), a mesoscale equatorial WTG (MEWTG) which reduces to the classical models treated by others, and a new seasonal planetary equatorial WTG (SPEWTG). Both the SPEWTG and MEWTG model equations have solutions with general vertical structure yet have the linearized dispersion relation of barotropic Rossby waves; thus, these models can play an important role in theories for midlatitude connections with the tropics. The models are derived both from the equatorial shallow water equations in a simplified context and also as distinguished limits from the compressible primitive equations in general.

Risk Management and Climate Change

Abstract: The selection of climate policies should be an exercise in risk management reflecting the many relevant sources of uncertainty Studies of climate change and its impacts rarely yield consensus on the distribution of exposure, vulnerability, or possible outcomes Hence policy analysis cannot effectively evaluate alternatives using standard approaches such as expected utility theory and benefit-cost analysis This Perspective highlights the value of robust decision-making tools designed for situations, such as evaluating climate policies, where generally agreed-upon probability distributions are not available and stakeholders differ in their degree of risk tolerance This broader risk management approach enables one to examine a range of possible outcomes and the uncertainty surrounding their likelihoods

Trading more food: Implications for land use, greenhouse gas emissions, and the food system

Abstract: The volume of agricultural trade increased by more than ten times throughout the past six decades and is likely to continue with high rates in the future. Thereby, it largely affects environment and climate. We analyse future trade scenarios covering the period of 2005–2045 by evaluating economic and environmental effects using the global land-use model MAgPIE (“Model of Agricultural Production and its Impact on the Environment”). This is the first trade study using spatially explicit mapping of land use patterns and greenhouse gas emissions. We focus on three scenarios: the reference scenario fixes current trade patterns, the policy scenario follows a historically derived liberalisation pathway, and the liberalisation scenario assumes a path, which ends with full trade liberalisation in 2045. Further trade liberalisation leads to lower global costs of food. Regions with comparative advantages like Latin America for cereals and oil crops and China for livestock products will export more. In contrast, regions like the Middle East, North Africa, and South Asia face the highest increases of imports. Deforestation, mainly in Latin America, leads to significant amounts of additional carbon emissions due to trade liberalisation. Non-CO2 emissions will mostly shift to China due to comparative advantages in livestock production and rising livestock demand in the region. Overall, further trade liberalisation leads to higher economic benefits at the expense of environment and climate, if no other regulations are put in place.

Positive feedback between global warming and atmospheric CO2 concentration inferred from past climate change

Abstract: [1] There is good evidence that higher global temperatures will promote a rise of greenhouse gas levels, implying a positive feedback which will increase the effect of anthropogenic emissions on global temperatures. However, the magnitude of this effect predicted by the available models remains highly uncertain, due to the accumulation of uncertainties in the processes thought to be involved. Here we present an alternative way of estimating the magnitude of the feedback effect based on reconstructed past changes. Linking this information with the mid-range Intergovernmental Panel on Climate Change estimation of the greenhouse gas effect on temperature we suggest that the feedback of global temperature on atmospheric CO2 will promote warming by an extra 15–78% on a century-scale. This estimate may be conservative as we did not account for synergistic effects of likely temperature moderated increase in other greenhouse gases. Our semi-empirical approach independently supports process based simulations suggesting that feedback may cause a considerable boost in warming.