By: Eemai Holt
The warming of our planet raises growing concerns about the health of the land and the well-being of the living beings that depend on its natural resources. A study published by the Department of Biology at Stanford University in December of 2023 “Taking Climate Change and Deforestation to Protect Against Vector-borne Diseases” reflects on how disruptions to the land and fluctuations in climate continue to increase the emergence of vector-borne diseases. Harmful acts such as deforestation and fossil fuel emissions considerably soil our atmosphere, water, and food systems that support life on Earth. Considering these environmental factors, it becomes increasingly difficult to ignore the significant role that our climate crisis has in exacerbating emerging infectious diseases in these dire conditions.
Climate change opens a window of opportunity for vector-borne diseases to arise in our environment. A vector-borne disease is caused and spread through pathogens such as viruses, bacterias, or parasites. Shifts in our ecosystem (like atmospheric warming) alter the balance of the natural niches of these organisms. Additionally, the persistence of our changing environment can alter human social interactions with our environment in a manner that makes us more susceptible to infectious pathogens.
Vector-borne diseases are defined as illnesses that emerge from pathogens or viruses that are transmitted through living organisms–such as mosquitoes and fleas. In order for a vector-borne disease to sustain in an environment, firstly the climate must be suitable. Secondly, humans must interact with the vector, allowing for the pathogens to be transmitted so that humans may be susceptible to them. Considering the frequency in which people come into contact with vectors (such as mosquitoes), our chances of developing an infectious illness continues to increase alongside climate disturbances.
Reflecting on the aftereffects of El Niño, the humid conditions cultivated the perfect climate for Dengue fever to materialize and spread. In the case of Dengue fever, warmer temperatures increase the reproduction and transmission rate of pathogens. Some vector-borne diseases have temperature thresholds that can either inhibit or encourage the transmission of the pathogen. As temperature irregularly increases during the cold seasons, the period in which vectors can transmit pathogens become extended. Land-use practices such as deforestation and urbanization can contribute to this by removing temperature-regulating forestation that otherwise absorbs carbon dioxide, allowing for warmer temperatures to persist. Along with elevated temperatures, the presence and absence of rainfall can create ideal vector reproduction sites. Periods of drought can attract mosquitoes to stagnant water sources and increased rainfall can create humidity for ticks.
Researchers also emphasize how socio-ecological factors can increase a population’s susceptibility to becoming infected with a vector-borne disease. Population density and human mobility add another variable of transmission that can increase the spread of pathogens amongst the human population. Human travel, transportation, and the development of urbanization can enhance infectious disease persistence and geographical dispersion. Additionally, certain at-risk populations might have a higher chance of coming into contact with infected vectors like houseless folks or those that work in agricultural settings. This intersection of corporate and environmental pressure widens the possibility of contact with these illnesses.
Another concern about exploitative land-use and climate change is its vulnerable relationship to an epidemic. Despite the development of vaccines and immunizations, some vector-borne diseases have long-lasting immunity which, in turn, cause them to re-emerge seasonally even after treatment. This increased resilience of infectious diseases further emphasizes the need for urgency in climate change reform on a universal scale.
In order to tackle climate change and exploitative land use practices, researchers urge for the intersection of science and policy implementation. Connecting the biological processes behind atmospheric warming to their impacts on the environment enables scientists, policymakers, and politicians to reframe climate change as not just an environmental issue, but also an economic and social justice concern. Researchers notably emphasize how the government holds the unique role of being able to implement policy that prohibits excessive carbon emissions and deforestation to help mitigate the rapid effects of climate change. Other preventative measures that could be taken by administrations to lessen the detriment of infectious diseases include preparing diverse outbreak response protocols, and increasing ecosystem conservation programs.
As climate change persists on Earth, we as humans have a unique opportunity in advocating for intersectional approaches towards protecting our ecosystems. Although this research study focuses on the emergence of vector-borne diseases and its threat to humans, every part of our ecological network continues to struggle as our atmosphere becomes warmer and warmer by the day.
