This segment of PRI’s Science Friday explores El Niño—what it is, why it forms, and its consequences around the world.
Director Dr. Aaron Bernstein and Dr. Robert Shmerling join the discussion to lend insight into the role of El Niño’s impact on health and communities.
He touches on how El Niño may be linked to cholera cases in Bangledesh, the dengue outbreak in Argentina, and the Zika virus in South America.
He notes that El Niño may give us a glimpse into the types of infectious diseases we may see as climate change unfolds.
El Nino is a naturally occurring phenomenon that has far-reaching effects on the climate, impacting tropical climates and global health. While the impact on temperature is persistent, El Nino's effects on health and communities worldwide will continue long after it dissipates. In this article, we explore the various ways in which El Nino impacts global health and how developing countries can prepare for the effects of climate change.
The Impact on Tropical Climates
El Nino's emergence in 2015 impacted tropical climates, particularly the timing of their rainy seasons. The resulting changes in precipitation create departures from the average, leading to droughts or floods in some areas. This disruption of the norm makes it difficult for livelihoods, agricultural systems, and economies that have been established around the average to cope with the effects. Developing countries, where populations are often more vulnerable to climate events, are exposed to infectious diseases that thrive in warmer, wetter conditions.
The Link to Vector-Borne Diseases
El Nino's impact on the climate has been linked to the emergence of vector-borne diseases, including cholera, dengue, and the Zika virus. Studies show that cholera outbreaks are more likely to occur in El Nino years due to copepod populations, small animals living in the ocean that harbor bacteria that do well in warmer waters. Similarly, dengue outbreaks are more common in El Nino years in Argentina, where the same mosquito that transmits the Zika virus thrives in the warmer, wetter conditions.
The disruption of the norm caused by El Nino also impacts food security. When the climate departs from the average, it can lead to droughts or floods, causing crop failures and food shortages. This disruption can lead to food insecurity in developing countries, which can be devastating for communities that rely on agriculture as their primary source of food and income.
Developing Countries' Access to Data and Analysis
Developing countries often lack access to the data and analyses that developed countries have about El Nino and the spread of disease. However, the influence of El Nino on the climate in the tropics makes the climate more predictable. Forecasts for future climate seasons ahead work better in the tropics because of El Nino, making it easier for poorer countries to plan ahead and position resources ahead of events to try and alleviate the issues for the population. Ethiopia is an excellent example of a country that understands how crucial climate is to its economy and livelihoods and has been working with meteorological services to get predictions ahead of time to position resources ahead of events to try and alleviate the issues for the population.
The Real-World Experiment for Climate Change
El Nino can be considered a real-world experiment that gives us hints about what might happen under climate change. El Nino events, because they have such profound effects upon temperature and precipitation around the world, give us a glimpse into the potential risks for infectious diseases we might see in a warmer world with more intense precipitation cycles. The diseases of humanity are climate-sensitive, and as climate change continues to unfold, we can expect to see a nasty set of unique conditions that can also have impacts on health and society. For example, La Nina has been linked to increased rainfall and flooding in some regions, which can lead to the spread of waterborne diseases and displacement of communities.
Understanding and preparing for the impacts of both El Nino and La Nina is critical for protecting public health and minimizing the disruption caused by these weather events. As Madeleine Thomson noted earlier, this requires investments in health information systems, climate data, and other tools for managing risk. It also requires a shift in mindset towards proactive rather than reactive approaches to public health and disaster response.
One key way to facilitate this shift is by increasing funding for research into the health impacts of climate change. As Aaron Bernstein noted earlier, the amount of funding currently allocated to this area is relatively small compared to the overall NIH budget. By increasing funding for research, we can better understand the complex relationships between climate, infectious diseases, and other health outcomes. This will in turn allow us to develop more effective strategies for protecting public health in the face of climate change.
Another important step is to increase awareness of the impacts of climate change on health, particularly among policymakers and the general public. By raising awareness of the potential health impacts of climate change, we can help to build support for proactive measures to mitigate these impacts.