Vulnerability to Climate Change is defined as the extent to which a natural or social system is susceptible to sustaining damage from climate changes. Vulnerability in this context therefore is related to the sensitivity of a system to a change in climate, i.e. the degree to which a system will respond to a given change in climate including both beneficial and harmful effects and the ability to adapt the system the changes in climate. Adaptation of necessity must focus on the degree to which adjustments in practices, processes or structures can moderate or offset the potential for damage, or take advantage of the opportunities created due to a given change in climate. Aerosols on the other hand tend to scatter out incoming radiation resulting in a cooling effect on the atmosphere. Unfortunately, the net effect remains as a warming due to the much shorter life spans of aerosols as against the much more long lived GHGs.
Water availability is an essential component of human welfare and productivity.
It is also highly probable that climate change will lead to changes in the global hydrological cycle, which in turn will affect the availability and distribution of regional water resources. Changes in the pattern and frequency of rainfall may cause shortages in fresh water supplies in many small island states. The vulnerability comes from the lack of redundancy in the system when primary sources fail e.g. rainfall. Most times the limited financial, technical and management resources cannot adapt efficiently to climate imposed stresses in the hydrological sector due to the heavy burden that is imposed on small economies. Flooding on the other hand, becomes a larger burden requiring special adaptation measures.