Four Global Catastrophic Risks – A Personal View

Russell Blong

doi:10.3389/feart.2021.740695

Abstract

Global catastrophic risks (GCRs) affect a larger than hemispheric area and produce death tolls of many millions and/or economic losses greater than several trillion USD. Here I explore the biophysical, social-economic, demographic and cultural strands of four global catastrophic risks – sea level rise, a VEI 7 eruption, a pandemic, and a geomagnetic storm – one human-exacerbated at the least, one geological, one biological in large part, and one from space. Durations of these biophysical events range from a day or two to more than 100 years and the hazards associated range from none to numerous. Each of the risks has an average return period of no more than a few hundred years and lie within a range where many regulators ordinarily demand efforts in the case of less extreme events at enhancing resilience. Losses produced by GCRs and other natural hazards are usually assessed in terms of human mortality or dollars but many less tangible losses are at least as significant. Despite the varying durations, biophysical characteristics, and the wide array of potential consequences, the aftermath at global (and at more granular scales) can be summarised by one of four potential futures. While this assessment considers the present and the near future (the Anthropocene), much of this appraisal applies also to global catastrophic risks in the Early Holocene.

Highlights

I offer thoughts on the likelihood of occurrence, character, and consequences of four global catastrophes
Since the beginning of the 20th century there have been at least five global Global catastrophic risks (GCRs): the 1914–1918 war (WW1); the 1918–1919 Influenza pandemic; the 1930s global depression; the 1939–1945 war (WW2); and, in 2019–2021, the COVID-19 Coronavirus pandemic
As we have discovered with COVID-19, the principal impact is not mortality but morbidity, leading to a reduction in consumption of many goods but stockpiling of others, restriction of movement with major effects on tourism, travel, hospitality, entertainment, transport, journey-to-work, exports and imports

Summary

INTRODUCTION

I offer thoughts on the likelihood of occurrence, character, and consequences of four global catastrophes (hereafter, often shortened to GCR). Loss potential is intended here to represent the consequences of a “middle-sized” global catastrophe rather than an “extreme” GCR event It is a general summation of all the consequences that might arise from the impact of the hazard across seven broad sectors – human health, social impacts, buildings, infrastructure, agriculture, other economic activity, and the environment – or, more generally, as shown on the lower five boxes on Figure 1. These estimates assume no coastal defences are in place so they indicate the scale of the investment required to offset the increase in risk They attribute 32% of the increase to sea level rise, 63% to tide and storm surge and 5% to wave setup, noting that most of the world’s flooding associated with the 1/100 years event could occur as frequently as 1/ 10 years in 2100

A Pandemic Equivalent to the 1918–1919 Influenza Pandemic

A VEI 7 Volcanic Eruption

Findings

DISCUSSION

CONCLUSION