Built Environment, Economic Development, Government Policy, Innovation, Poverty, Water and Sanitation

Climate Change and Health, Part 1: Floods

~Written by Joann Varickanickal (Contact: joann.varickanickal@gmail.com)

The Lancet recently published an article on climate change and health, extensively examining the types of health risks related to climate change as well as recommendations for policy changes, in order to address these risks (Watts et al., 2015). This article re-emphasized how complex this issue is because there are several contributing factors, and elements that can be potentially impacted (Figure 1).  As there are so many aspects of this topic, for my next few blog posts I will focus on briefly highlighting some of the health risks associated with climate change. This post will focus on natural disasters, specifically looking at floods.

Figure 1: Relationship between health, climate change and greenhouse gas emission (Watts et al., 2015)

Since 1900, floods have left more than 88 million people homeless, $595 billion in damages, and the deaths of nearly 7 million people (Khedun & Singh, 2013). Overall, climate change will have a direct impact on human health through natural disasters, such as flooding. South Asia is especially at risk as there is already regular flooding. A change in climate can affect the onset of monsoons. For example, in Kerala, a state in southern India, the monsoon season generally begins on June 1st and ends in early September, with a standard deviation of about seven days (Mirza, 2011). However, in the last 50 years this has more than doubled with the earliest onset on May 14th, and the latest date of onset on June 18th (Mirza, 2011). While this may not seem significant, it can influence the level of preparedness in communities that are at risk. Furthermore, the frequency and intensity of rainfalls will also increase. According to climate models, monsoon intensity increases during the summer, as the air over land is warmer than air over the oceans (Mirza, 2011). Floods, that result from the monsoon weather, not only increase the risk of drowning, but also affect the quality of water, thus increasing the exposure to waterborne diseases such as dysentery and diarrhea (Mirza, 2011).

Mental health issues, such as anxiety and depression, can also develop after losing property or facing a financial crisis after a flood (Khedun & Singh, 2013). Furthermore, the impacts of climate change, such as increased flooding, disproportionately influence certain populations such as marginalized communities, women, children, and the elderly (Watts et al., 2015). Thus, they suffer most of the negative health consequences associated with flooding and other disasters related to climate change (Watts et al., 2015). This highlights the complexity of the issue in terms of trying to address how to help those who are most impacted by floods.

There are several mitigation efforts that can be taken in order to reduce the impact of floods. For example, urban planners and engineers can work to ensure that forested areas are preserved and development occurs in areas where soil and vegetation conditions work best to reduce the risk of flooding. Many non-structural methods can also be implemented. For example, in some areas it may be beneficial to create zoning laws that would prohibit development in areas that are prone to flooding (Watts et al., 2015). Government officials and private officials can also work together to improve early warning systems and develop better policies for flood-insurance and emergency preparedness (Watts et al., 2015). Taking these steps can help to ensure that health issues associated with floods will not be exacerbated.


Khedun, C. P., & Singh, V. P. (2013). Climate Change, Water, and Health: A Review of Regional Challenges. Water Quality, Exposure and Health, 6(1-2), 7–17. doi:10.1007/s12403-013-0107-1

Mirza, M. M. Q. (2011). Climate change, flooding in South Asia and implications. Regional Environmental Change, 11(SUPPL. 1), 95–107. doi:10.1007/s10113-010-0184-7

Watts, N., Adger, W. N., Agnolucci, P., Blackstock, J., Byass, P., Cai, W., … Costello, A. (2015). Health and climate change: policy responses to protect public health. The Lancet, 6736(15). doi:10.1016/S0140-6736(15)60854-6