Germanwatch

Methodological Remarks

The presented analyses are based on the worldwide data collection and analysis provided by MunichRe’s NatCatSERVICE.¹¹⁹ “The information collated by MunichRe, the world’s leading re-insurance company, can be used to document and perform risk and trend analyses on the extent and intensity of individual natural hazard events in various parts of the world.”¹²⁰ Broken down by countries and territories, MunichRe collects the number of total losses caused by weather events, the number of deaths, the insured damages and the total economic damages. The last two indicators are stated in million US$ (original values, inflation adjusted).

In the present analysis, only weather-related events – storms, floods as well as temperature extremes and mass movements (heat and cold waves etc.) – are incorporated. Geological incidents like earthquakes, volcanic eruptions or tsunamis, for which data are also available, are not relevant in this context as they do not depend on the weather and therefore are not possibly related to climate change. To enhance the manageability of the large amount of data, the different categories within the weather-related events were combined. For single case studies on particularly devastating events, it is stated whether they concern floods, storms or another type of event.

It is important to note that this event-related examination does not allow for an assessment of continuous changes of important climate parameters. For instance, a long-term decline in precipitation that was shown in some African countries as a consequence of climate change cannot be displayed by the CRI. Nevertheless, such parameters often substantially influence important development factors like agricultural outputs and the availability of drinking water.

Preparing an index requires the analysis of a vast amount of data. Thus, data availability and quality play an important role as well as the underlying methodology for their collection. For instance, the accurate attribution of a human loss to a particular extreme weather event faces certain methodological boundaries that data collectors have to work with (e.g. to determine whether the death of an elderly person during a heatwave is indeed the result of the extreme temperature or due to the high age alone). Similarly, data quality and coverage may vary from country to country as well as within countries. A study by Campbell et al. (2018) found that heatwave and health impact research is not evenly distributed across the globe. They highlight that “regions most at risk from heatwaves and health impact are under-represented in the research.”¹²¹ The data analysed for the CRI rely on scientific best practice and methodologies used are constantly evolving with the view of ensuring the highest degree of accuracy, completeness and granularity.

Although certainly an interesting area for analysis, the present data do not allow for comprehensive conclusions about the distribution of damages below the national level. The respective data quality would only be sufficient for a limited number of countries. The island of Réunion, for example, would qualify for a separate treatment but data are insufficient.