Socioeconomic impacts
Nature's upheaval can have far-reaching socioeconomic consequences. Several times in history it has caused people to migrate. Today the general pattern is that low-income countries pay the price of natural disasters in human lives while high-income countries pay in material damages. In poor countries next to nothing is insured, while in rich countries almost everything is.
Earth's growing population causes more and more people to come within the influence of natural hazards. This effect is further amplified by settling patterns where population density often rises most in risk-prone areas close to the ocean and seashore and close to rivers. There were 3 conurbations (metropolitan areas with >10 million inhabitants) in 1972, 13 in 1992 and 24 in 2000. Urbanization automatically results in a geographical concentration of investments (material value per km2) through the building of roads, water and electricity lines, etc. City planners are generally not well informed about natural hazards and their periodicity.
Several percent of the constant building around the world is dedicated to replacing the damage that natural disasters have caused. There are a number of cities in the world that should not be allowed to grow, as they are very badly located from a natural hazards perspective. Mexico City and Tokyo are examples of such cities inland, while Alexandria, Mumbai, Kolkata, Dhaka, Bangkok, Tianjin, Yokohama, San Francisco, and New Orleans are examples of coastal cities at risk. We will hear more about these and other risk-prone cities in the future.
Presently politicians are focusing their attention on carbon dioxide emissions, even though the earthquakes in Kobe 1995, in Iran 2003, the tsunami of 2004 in the Indian Ocean, the west Atlantic hurricane Katrina in August of 2005 and the earthquake in Pakistan in October 2005 should have made everybody realize that rapid upheaval is what affects us the most.
When building houses and roads stone is required. Deep weathering of bedrock in all tropical areas makes fresh rock difficult to come by. Volcanic eruptions give either lava, that makes a very good building material, or pyroclastic material that can be light and isolates well. Natural Hazards Group has knowledge of where eruption products can be found and when they are replenished.
All natural hazards except an extraterrestrial collision are dwarfed by the biggest volcanic eruptions.