On the representation of impact in integrated assessment models of climate change

The paper provides an overview of attempts to represent climate change impact in over twenty integrated assessment models (IAMs) of climate change. Focusing on policy optimization IAMs, the paper critically compares modeling solutions, discusses alternatives and outlines important areas for improvement. Perhaps the most crucial area of improvement concerns the dynamic representation of impact, where more credible functional forms need to be developed to express time‐dependent damage as a function of changing socio‐economic circumstances, vulnerability, degree of adaptation, and the speed as well as the absolute level of climate change.     

The Social Costs of Climate Change: The IPCC Second Assessment Report and Beyond

Climate change is expected to have far-reaching impacts. Earlier studies have estimated an aggregated monetised damage equivalent to 1.5 to 2.0 % of World GDP (for 2 × CO₂). According to these estimates, the OECD would face losses equivalent to 1.0 to 1.5 % of GDP, and developing countries 2.0 to 9.0 %. While these figures are preliminary and highly uncertain, recent findings have not, as yet, changed the general picture. As is shown in this paper, estimates that are fully corrected for differences in purchasing power parity do not significantly differ from the initial figures. Newer studies increasingly emphasise adaptation, variability, extreme events, other (non-climate change) stress factors, and the need for integrated assessment of damages. Incorporating these factors has lead to increased differences in estimated impacts between different regions and sectors. Estimates of market impacts in developed countries tended to fall, while non-market impacts have become more important. Marginal damages are more interesting from a policy point of view. Earlier estimates range from about $5 to $125 per tonne of carbon, with most estimates at the lower end of this range. These figures are based on power functions in the level of climate change. The rate of change may be equally important, as are the speed of adaptation, restoration and value adjustment. Furthermore, future vulnerability to climate change will differ from current vulnerability: market impacts could fall (relatively) with economic growth while non-market impacts may rise. This revised version was published online in August 2006 with corrections to the Cover Date.     

Ozone Levels in the Vicinity of 33 Cities

Hourly concentrations of ozone were measured by the chemiluminescence method during the summer of 1971 in the vicinity of 33 cities. A listing was made of the percent of time the National Air Quality Standard for photochemical oxidants was violated. At 4 selected cities the daytime and nighttime average concentrations were related to wind directions showing the direction to source areas. Another set of tables and graphs was used to show the source directions for high concentrations (equal to or above 120 µg/m³) and disregarding the times of more usual or background concentrations. Numerous occasions of high ozone concentrations occurred when wind directions were apparently from areas with low concentrations of the known precursors. Because of this, other sources of ozone were considered such as thunderstorms and the transport of ozone for long distances. Examples of ozone concentrations during thunderstorms or related to long distance transport are cited.     

The Value of Human Life in Global Warming Impacts – a Comment

Mitigation and Adaptation Strategies for Global Change -     

Measuring the Incremental Costs of Global Environment Protection: The Case of Grid-Connected Wind Turbines in Morocco

An application is presented of the methodology used bythe Global Environment Facility (GEF) to measureincremental costs. Incremental cost estimates are usedby the GEF to determine its financial contribution toprojects that protect the global environment, such asinvestments in renewable energy. The importance ofadopting a system-wide view in certain types ofprojects (such as investments in grid-connected power)is illustrated using the case of wind power inMorocco. A narrow plant-by-plant comparison wouldneglect the adjustments in the system expansion planthat may be warranted when one type of plant (e.g., acoal fired thermal plant) is replaced by another (e.g.,a wind farm).     

Adaptation investments: a resource allocation framework

Additional finance for adaptation is an important element of the emerging international climate change framework. This paper discusses how adaptation funding may be allocated among developing countries in a transparent, efficient and equitable way. We propose an approach based on three criteria: the climate change impacts experienced in a country, a country’s adaptive capacity and its implementation capacity. Physical impact and adaptive capacity together determine a country’s vulnerability to climate change. It seems both efficient and fair that countries which are more vulnerable should have a stronger claim on adaptation resources. The third dimension, implementation capacity, introduces a measure of adaptation effectiveness. Rough indicators are proposed for each of the three dimensions. The results are indicative only, but they suggest a strong focus of initial adaptation funding on Africa. African countries are highly vulnerability in part because of the severity of expected impacts, but also because of their very low adaptive capacity. However, their implementation capacity is also limited, suggesting a need for technical assistance in project implementation.