Attributing a single event to climate change remains difficult at present but the long-term trend is clear: natural catastrophes are becoming more frequent and the intensity of certain perils is also estimated to increase. Guy Carpenter’s new report, Protecting our Planet and the Public Purse, highlights the expected geographic distribution of public sector risks as global temperatures increase.
According to Munich Re, there were close to 850 natural catastrophe events in 2018 (see Figure 5), the highest number on record and a three-fold increase from the early 1980s. In the past decade, the quantum of natural catastrophes has increased by over 70 percent. Climate-related events, particularly hurricanes, typhoons and floods, account for virtually all of this increase. This trend could accelerate in the future as some climate research finds increased persistence in jet stream patterns that could cause a succession of catastrophe events over the same region during an individual season.
The increased frequency of catastrophes reinforces the need for governments worldwide to prepare for more climate-driven events in the future. The continued appeal of living in areas exposed to weather-related risks is also having a significant bearing as more people are being affected by events that would otherwise have gone unnoticed or unreported.
Predictions about how climate change will manifest across different regions of the globe are still subject to uncertainty. The macro trend of rising global temperatures is clear and has already been addressed in this report: human-induced warming has reached approximately 1°C above pre-industrial levels and is also increasing at approximately 0.2°C per decade.
The more localized impacts are less clear cut. Global climate models, many of which have been in use for over a decade, are designed to model the entire world and run over long time horizons. By their very nature, they are unable to resolve more localized events (such as tornados and hailstorms), but they perform well at capturing and forecasting observed global warming trends. Climate experts are also increasingly able to extrapolate shifts in smaller scale, impactful events, by measuring temperature and moisture trends from the climate models that are more/less conducive to these types of catastrophes.
A strong consensus is therefore being formed on the broad impacts of climate change, and these are supported by scientific theory and data observations. Global warming has already caused multiple observed changes in the climate system. These changes include increases in both land and ocean temperatures, as well as more frequent heatwaves in most land regions and marine areas.
In addition, there is substantial evidence that human-induced global warming has also led to an increase in the frequency, intensity and/or amount of heavy precipitation events at a global level, as well as an increased risk of drought. While average global rainfall amounts are not expected to grow substantially, the daily (and sub-daily) rainfall amounts are forecast to increase, in part down to the pure physics of the atmosphere holding more moisture in warmer climates and conditions becoming more optimal for storm development and increased intensity.
Put simply, extremes will become more extreme, with wetter areas getting wetter and drier areas getting drier. Figure 6 outlines in some detail the perils and impacts various regions around the world are expected to experience under different climate change scenarios.
Impacts will clearly vary by location, with some regions only marginally affected while others will experience disproportionally severe effects. The level of information contained in Figure 6 is worthy of an entire paper, but for the purposes of this report, we briefly address two consequences of climate change that are front and center: sea level rise and wildfire.