HURRICANES AND CLIMATE CHANGE: Disasters waiting to happen?
By Fabio Cresta Aleína
The wounds opened by hurricanes Eta and Iota are still heavily felt in Guatemala and in whole Central America. This year, during a record-breaking hurricane season, 30 Atlantic storms have been named, meaning that 30 tropical cyclones intensified to the point that their winds were faster than 63 km/h. The devastation in Guatemala is terrible. The village of Quejá in Alta Verapaz, for example, has been catastrophically affected by the fury of Eta, as violent rains triggered landslides that buried houses and people. And after Eta came Iota, and two hurricanes arriving in such a quick succession is a tragedy hitting even harder because of the massive flooding caused by the oversaturation of the soil and because it affected a population already struggling to survive.
The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) identified hurricanes and tropical storms as the most damaging natural disasters in Central America. The World Bank conducted two major studies in the region in the past years and found out that hurricanes are responsible for a decrease in the growth of the total per-capita gross domestic product (GDP) of between 0.9% to 1.6%, and that they are also responsible for an average 1.5% growth in poverty. Generally, the World Bank studies showed that hurricane impacts are most heavily felt in the first year after the disaster, and they urged a swift response for a more sustainable reconstruction and recovery.
So, is climate change to blame for all this? The answer is not completely straightforward, and climate scientists spent years in order to find it. Hurricanes, like other storms, are strictly speaking meteorological phenomena, and therefore per se not a sign of climate change. Nevertheless, climate scientists warn that a warming world, and a warming sea surface temperature in particular, will lead to an increase in the intensity of the cyclones. A recent study by James Kossin and colleagues that appeared in the Proceedings of the National Academy of Sciences (PNAS) in May 2020 highlighted that the maximum intensity of tropical cyclones in average has increased in the past 30 years. The mechanism that leads to the formation of hurricanes, which involves the evaporation of warm seawater, has been fairly well understood for decades. Already in 1987, a seminal study by Kerry Emanuel showed with a theoretical model that the intensity of tropical cyclones (meaning, the wind velocity and therefore their destructive potential) would increase with an increase in temperature due to higher concentrations of greenhouse gases in the atmosphere.
It has been very difficult to robustly verify these theoretical findings, though, as winds in hurricanes and in other tropical storms are not easily measured. In the new PNAS study, Kossin and colleagues overcame this technical difficulty by analyzing an extensive satellite dataset. Their results, unfortunately, confirmed the theory elaborated by Emanuel over 30 years ago. Hurricanes are actually getting stronger and delivering even more rain, and this is, in fact, a consequence of climate change. An increase in storm intensity does not mean an increase in the frequency of hurricanes hitting Central America, but it does mean an increase in the frequency of the most intense storms, and in particular the ones leading to the heaviest toll of damage and destruction. Moreover, hurricane surges (coastal floods caused by tropical storms, also called storm tides), which are among the most damaging consequences of hurricanes on the coasts, are also predicted to increase because of the combination of the increased wind intensity with the sea level rise. The resulting combination of more violent hurricanes and higher surges will cause a rapid rise in the climate-associated risks for millions of people in Central America, especially along the Atlantic coasts.
The increasing trend in the damage caused by such extreme events, in turn, has deep societal consequences. Extreme and catastrophic events are deemed to affect the most vulnerable parts of the society, particularly this year because of the economic instability caused by the COVID-19 pandemic. Moreover, with the pandemic being far from over, the activities related to disaster relief and reconstruction, while being necessary, may lead to a further spread of the virus in the affected communities. Recently, the International Organization for Migration (IOM) declared that it plans to increase the support activities in Nicaragua, Honduras and Guatemala because of the consequences of the hurricanes. Officers of the IOM, analyzing the dramatic situation, considered that it will take several years for the reconstruction and recovery to take place in a sustainable way. Eta and Iota changed the lives of millions of people, and the long-term consequences of the disaster will be hardly felt for years to come, even outside the afflicted countries, as hundreds of thousands of people lost everything. In Guatemala, the IOM reports that over 17,000 people are housed in emergency shelters, prepared before the hurricanes hit, and together with the authorities of Puerto Barrios, the IOM led the implementation of the Integrated Shelter Registration System (SIRA), meant to collect information on the population affected by the storms – especially in Izabal. Despite the efforts of local authorities, of many NGOs and of individuals working in the region, though, the preparation and the response to this crisis has been insufficient, so far, and new UN data show that over 400,000 people are still waiting for humanitarian aid in Honduras and Guatemala.
International and governmental interventions in the affected regions are sorely needed also to avoid mass migrations of the people who lost everything in the wake of the storms. The IOM advocates for long-term investments, which are able to take into account the sustainable developments in the affected departments. Such investments will not only help the affected population to recover and to reconstruct the destroyed infrastructures but will ideally enable them to face the inevitable future natural disasters. And it is exactly such a long-term perspective and such a forward-looking sustainable plan which takes into account future threats that should be the focus of any relief program, after the delivering of the first aid. We now know that climate change is going to make hurricanes even more dangerous, and what we need are better adaptation strategies to be put in place at all levels, from the international community, to the national governments and to the civil society.
References and further readings:
K. Emanuel, The dependence of hurricane intensity on climate. Nature 326, 483–485 (1987).
K. Emanuel, Evidence that hurricanes are getting stronger. Proc. Natl. Acad. Sci. U.S.A., 117 (24) 13194-13195 (2020).
O. A. Ishizawa Escudero, J. J. Miranda Montero 2016. Weathering Storms: Understanding the Impact of Natural Disasters on the Poor in Central America. Policy Research Working Paper; No. 7692. World Bank, Washington, DC.
O. A. Ishizawa Escudero, J. J. Miranda Montero, H. Zhang. Understanding the impact of windstorms on economic activity from night lights in Central America. Policy Research Working Paper; No. WPS 8124. World Bank, Washington, DC (2017).
J. P. Kossin, K. R. Knapp, T. L. Olander, C. S. Velden, Global increase in major tropical cyclone exceedance probability over the past four decades. Proc. Natl. Acad. Sci. U.S.A. 117, 11975–11980 (2020).
N. Lin, K. Emanuel, M. Oppenheimer, & E. Vanmarcke. Physically based assessment of hurricane surge threat under climate change. Nature Climate Change, 2(6), 462–467 (2012).
Natural Disasters in Latin America and the Caribbean, 2000-2019, United Nations Office for the Coordination of Humanitarian Affairs (2020)