Hurricane Season: Do Warmer Oceans Mean More Cyclone Damage?

As oceans heat up in response to climate change, more water evaporates from the surface and acts as fuel for tropical cyclones.  These hurricanes, fed by warm and moist air, create steep pressure gradients and eventually form into the iconic spiral of clouds and wind spotted on weather station updates.  Currently costing the world US 26 billion dollars per year in damage, these tropical storms bring storm surges, high winds, and coastal flooding, all of which contribute to loss of human life and economic damage.  As carbon emissions continue to rise, scientists are trying to predict what warmer oceans implicate for hurricane seasons around the world.
 
In a recent paper published in Nature magazine, a group of scientists from Yale and MIT creates a tropical cyclone assessment model to predict, given different emissions scenarios, the location, frequency, and intensity of tropical cyclones across global ocean basins.  Combining a cyclone model with several climate models, they generate a set of 17,000 simulated storms based on current emission scenarios. Using data about wind speed, sea surface temperature, and barometric pressure, the team was able to generate detailed information about predicted storm paths and damage in different ocean basins.
 
After analyzing the synthetic storms, the researchers show that climate changes increase the frequency of the most powerful storms. The most storm damage now is caused by only 10% of tropical storms, and these large, powerful cyclones, according to the model, will begin to happen more frequently as the planet heats up.  In agreement with other models, their results suggest the number of small storms worldwide may not increase, but that data does show an uptick in high-intensity events.  This increase, however, is not distributed evenly throughout the globe. The Atlantic and Northeast Pacific oceans are expected to see more powerful storms and the Northwest Pacific, North Indian, and Southern Hemisphere basins show less significant or mixed projections. 
 
This study is particularly interesting because the researchers then plugged this information into a damage calculator to predict how much damage the storms could do based on population distribution and income.  Incomes are rising worldwide and more people and capital are shifting into the wake of tropical cyclones. With more powerful storms on the horizon, more economic damage is inevitable. Based on these trends, the researchers states cyclone damage costs will double to $56 billion by 2100. Costs from cyclone damage, however, will not be distributed equally. Some parts of the world, like North Africa, the Middle East, and South America are not predicted to receive any more storms. Other places like Europe will only see low-intensity storms, while Sub Saharan Africa, with fewer assets in the way of the storms, will not see a significant increase in damage. The regions and countries facing the greatest increase in high-intensity storms and corresponding economic damage are China and the United States, while areas in the Caribbean-Central Americas, North America and East Asia following.
 
While the cyclone model does not take into account regional differences within countries or sea level rise, the research results have enormous implications for coastal resiliency planning. Further research, including the development of additional scientific and economic models for storms is needed to inform policy and management. As urbanization continues and capital shifts within and between countries, planners, resource managers, and policy-makers will be faced with difficult decisions about coastal development. With more intense storms on the horizon, more assets may need to be moved out of harm's way.