Climate changes and the local environment:
Haiti is a country prone to extreme weather: floods, droughts, and especially hurricanes. Typically, hurricanes make landfall on the southern coast of Haiti, and as a result communities located there experience the greatest storm surges. The largest city on a south-facing coastline is the commune of Gonaïves.
The frequency of Atlantic hurricanes has increased sharply since the 1980s, and seems to have risen overall since the 19th century. However, it is hard to determine exactly how many hurricanes churned through the Atlantic before the widespread use of weather satellites. Our understanding of long-term trends in hurricane frequency may therefore be skewed by early underreporting of remote or short-lived hurricanes.
Still, it seems clear that major hurricanes in particular have grown more common as sea surface temperatures warm across the Atlantic, and particularly in the Caribbean Sea. Hurricanes are fueled by warm, moist air rising from warm water. The warmer the water, the more fuel hurricanes can use.
The most powerful hurricanes, with sustained winds at or above 130 mph (209 km/h), have rarely made landfall in Haiti. Category 5 hurricane Irma, for example, only lightly grazed northern Haiti. Yet substantial hurricanes have recently made made landfall in Haiti and caused catastrophic flooding in Gonaïves. Moreover, hurricane storm surges are higher now than they once were, owing in part to a modest but sustained increase sea levels on the Haitian coast.
Hurricane floods have also been slow to recede from Gonaïves, owing to surrounding mountains that trap water within the commune. Long-lasting floods have raised the salinity of soil and groundwater around Gonaïves, and have thereby repeatedly hindered rice cultivation. Meanwhile, deforestation on and around the mountains near Gonaïves has led to mudslides amid torrential rainfall during and after hurricanes.
How we know:
This summary makes use of reconstructions compiled by the National Oceanic and Atmospheric Administration (NOAA) National Hurricane Center, which provides easy to use visualizations that record the history of hurricanes in the Atlantic Basin.
It also draws on an overview of changes in hurricane frequency provided within the U.S. National Climate Assessment, and a skeptical assessment of hurricane trends published by the NOAA Geophysical Fluid Dynamics Laboratory.
Haiti today is almost entirely deforested, and that has greatly increased the vulnerability of its coastal cities to hurricanes. Beginning in the seventeenth century, European settlers imported slaves from Africa to work in plantations that destroyed much of the indigenous forest of the island of Hispaniola, which includes Haiti. Late in the twentieth century, impoverished Haitians destroyed almost all the forests that remained in order to exploit charcoal. With oil and coal too expensive for most Haitians to afford, charcoal provided one of the few accessible sources of fuel. Exposed hillsides now offer no resistance to floodwaters, and easily crumble in devastating mudslides. Meanwhile, nearly all of Haiti's watersheds are deforested.
In this context, active hurricane seasons can provoke human suffering on a vast scale across Haiti, and those seasons have grown more common. In 2004, for example, Hurricane Jeane dropped 13 inches of rain on the northern mountains of Haiti and caused catastrophic flooding in and around Gonaïves. Nearly 3,000 Haitians lost their lives. In 2008, no fewer than four hurricanes made landfall in Haiti. Floods were particularly devastating in Gonaïves, but overall houses belonging to nearly 800,000 Haitians were either damaged or destroyed. Floods swept away roughly 70% of Haiti's crops and thereby provoked widespread hunger and malnutrition. Festering flood waters provided ideal conditions for the spread of cholera, malaria, and West Nile disease. In 2016, Hurricane Matthew, a major category 4 storm, devastated southern Haiti and killed over 900 people.
Haitians have not remained passive in the face of these challenges. Recently, the Haitian government has partnered with international aid groups and celebrities to launch a major reforestation program. International efforts, meanwhile, aim at reducing social and gender inequality across Haiti, and thereby fostering resilience to climate change in communities such as Gonaïves.
Article author: Armelle Déjoie, Georgetown University
Article editor: Dr. Dagomar Degroot, Georgetown University