Perhaps the greatest threat we face isn’t one of the catastrophes listed above, but rather a combination of such threats. We live in a complex, interconnected world with many vulnerabilities, and disasters can negatively affect multiple aspects of a system.
A stressor becomes a threat multiplier if it exacerbates other threats, especially those related to national security. Many experts believe climate change is a threat multiplier. For example, droughts and high temperatures are expected to be deadly on their own, but they will also increase the numbers of refugees seeking asylum in countries with more food. Meanwhile, the combination of increased temperatures and refugees living in close quarters could increase the likelihood of a pandemic even deadlier than COVID-19. Additionally, a refugee crisis, especially if paired with a pandemic, could lead to border conflicts and an increased chance of war between various countries. If this were to occur between two nuclear countries, the risk of nuclear war and a subsequent nuclear winter would also increase.
Most catastrophic risks come with the threat of triggering further catastrophes if we don’t address them quickly and effectively.
For many years, scientists considered the impacts of hazards and disasters individually, but there’s a growing recognition that disasters can often occur at the same time or trigger other disasters. For example, droughts are often accompanied by heat waves, while earthquakes often trigger deadly tsunamis. A megatsunami, triggered by a large earthquake or massive landslide, could destroy many ports.
As COVID-19 swept across the globe, many countries in Africa, the Middle East, and Southeast Asia were also in the midst of one of the worst outbreaks of locust swarms in decades. The compounding effect of the global response to COVID-19 (i.e., lockdowns and restriction of movement of workers) and the locust swarms together increased global food stress far more than either event on its own might have done.