**2. Climate change and environmental degradation**

#### **2.1 Main characteristics of climate change**

According to the IPCC Third Assessment Report, the global average surface air temperature is projected to increase by 1.4 to 5.8°C by 2100 [8], with significant impacts on all elements of the global climate system. In addition, the fifth report

#### *Vector-Borne Diseases and Climate Change in the Environmental Context in Haiti DOI: http://dx.doi.org/10.5772/intechopen.96037*

published in 2014 also reveals that all physical and biological systems on all continents and in virtually all oceans will be affected by temperature increases due to climate change [9]. Therefore, changes in climatic conditions and induced effects such as rainfall variability, temperature, humidity affect the human and ecological systems of the planet. However, rising temperatures and increased drought periods generally lead to new challenges that are very difficult for a developing country to overcome.

The IPCC [10] predicts that climate change will affect coastal areas in a variety of ways and indicates that current changes in temperature and precipitation are likely to increase the frequency of life-threatening events. Changes in climate variability will also have consequences for human health. Climate variables such as temperature and precipitation have a major impact on the hydrological cycle and changes in these variables will alter runoff and evaporation patterns and the amount of water stored in soils and aquifers. They could also degrade groundwater quality. For example, a reduction in aquifer recharge rates and groundwater runoff could increase contaminant concentrations in groundwater and the incidence of infectious diseases. Work carried out in the cities of Cap-Haitian and Les Cayes (Haiti) has highlighted the presence of *Cryptosporidium* oocyst in surface water [11–13] and groundwater used by the population for domestic purposes [14]. These resources are contaminated by fecal pollution and are a source of potential biological risk to the health of the exposed population. Rainfall can promote the spread of infectious agents, while temperature promotes their proliferation and survival.

### **2.2 State of environmental degradation in Haiti**

Developing countries (DCs) face the challenges of population growth, accelerated urbanization and poverty. On one hand, socio-economic inequalities and social polarization have increased, and on the other hand, the heterogeneity of poor households has grown, including the increase in socio-economic inequalities and social polarization [15]. According to the data in the literature, some developing countries are more subject to the impacts of climatic variations, especially those with an "extreme" climate and/or those whose climate is close to that of the sea. Haiti is one of these, mainly due to its high population growth juxtaposed with conditions of economic and social poverty.

Located on the border of two tectonic plates (the North American Plate and the Caribbean Plate located under the Caribbean Sea) [16], Haiti is not only placed on the direct trajectory of extreme weather events such as storms and hurricanes, but is also the site of strong seismic activity that seriously damages its socio-economic development process [17]. In addition, in recent decades, the process of degradation of Haiti's biophysical environment and its socio-economic decline has been exacerbated by climate change. Indeed, the second national communication on climate change and recent studies on the issue have revealed the high vulnerability of the country's main strategic sectors to this occurrence. Haiti is exposed to environmental threats such as sea level rise, the intensification of extreme weather events (hurricanes, floods, droughts, etc.), erosion and coastal pollution.

The demographic explosion currently characterizing the country is leading to deforestation, resulting in impoverishment and soil degradation. This deforestation makes the country particularly vulnerable to floods and erosion. Every year it loses about 1600 t/ha of land [18]. **Figure 1** shows the impact of deforestation on the Pine Forest Biological Reserve [18].

Haiti has a geophysical environment characterized primarily by particular climatic, hydrological and biogeographic phenomena. Environmental changes such as deforestation, desertification, soil erosion and extreme poverty linked to its geographical location make the country increasingly vulnerable to climate change. According to 2014'sGerman Watch long-term climate risk index, Haiti was,

#### **Figure 1.** *Pine Forest Deforestation in Haiti [18].*

between 1990 and 2008, the Caribbean country most affected by natural disasters (epidemics, floods, storms and hurricanes). These phenomena demonstrate the extent to which climate change contributes to environmental degradation, i.e. soil degradation, water scarcity, water pollution, loss of biodiversity and the occurrence of diseases. Haiti ranks third among the countries most affected by climate risks between 1993 and 2012 [19].

For developing countries, particularly Haiti, climate change represents a new threat that adds to existing risks, interacts with them and amplifies them. The negative consequences of climate change are exacerbated by the increased occurrence of extreme weather events, such as major hurricanes. These, which are increasingly intense, threaten to undermine the functioning of the various sectors associated with the country's socio-economic development, causing damage reaching alarming proportions of the national GDP. It is in this context and following the impetus provided by the Paris Agreement that the Haitian government, through the Ministry of the Environment (MDE) supported by the country's key sectors and actors, proceeded to develop the National Climate Change Policy (NCCP) following a highly participatory and inclusive process. This policy seeks to establish the major projects of the Haitian State in this area. As such, it should serve as a guide for all sectors and actors who want to contribute to the fight against climate change.
