Samaan Lateef | New Delhi
The escalating global temperatures and the rapid increase in greenhouse gas emissions, largely resulting from the burning of fossil fuels, have brought about profound and concerning effects on climate change’s impact on public health.
A comprehensive study published by The New England Journal of Medicine has shed light on the alarming effects of climate change on global health. The study highlights the widespread and rapidly intensifying consequences of rising temperatures and greenhouse gas emissions, primarily caused by burning fossil fuels.
The research reveals that global mean temperatures have already risen by 1.1°C since 1900, with the most significant changes occurring over the past 50 years. Notably, highland and polar regions have experienced the most extreme shifts. Tropical regions, meanwhile, are inching closer to the thermal limits of various organisms, raising concerns about the potential impact on vulnerable populations.
If current policies and actions remain unchanged, experts predict a warming of 2.5°C to 2.9°C or more by the end of this century, painting a bleak picture for the future of our planet.
Of particular concern is the intricate relationship between climate change and vectorborne diseases, as outlined in the study. Climate-driven changes in precipitation patterns, including increased flooding and droughts, significantly affect pathogens, vectors, and hosts, while also hampering prevention and treatment efforts. However, attributing these changes solely to climate change poses challenges, as other factors like land-use changes and control measures also play a role.
Nevertheless, the study establishes that the various components of vectorborne disease systems, including pathogens, vectors, and reservoir hosts, respond significantly to the environments they inhabit. Consequently, shifts in local climate are often accompanied by changes in the rates of vectorborne diseases.
For instance, rising temperatures impact the behavior, physiology, and life cycles of vectors, pathogens, and reservoir hosts, altering the risk of disease transmission. The study points to thermal performance curves as a key tool in predicting the potential effects of climate change on these disease systems. Depending on their ability to adapt, vectors may no longer carry certain pathogens or may transmit new ones, as climate-mediated ecosystem changes bring together different disease-carrying organisms.
The study identifies several climate-sensitive vectorborne diseases that have already shown increased prevalence in recent decades. Malaria, dengue, Lyme disease, and West Nile virus infection are among the most notable examples. According to the Intergovernmental Panel on Climate Change (IPCC), without effective adaptation and control strategies, the prevalence of these diseases is expected to surge over the next 80 years.
In addition to the direct health implications, climate change exacerbates existing inequalities, particularly in less developed countries. Poverty, inadequate housing, poor environmental conditions, and limited access to quality healthcare further magnify the vulnerability of affected populations, including children, women, and older adults.
To mitigate the risks and strengthen public health responses, the study emphasizes the importance of investments in surveillance, control, and adaptation strategies. Climate-informed early-warning systems, improved access to prevention measures such as mosquito control and vaccines, and sustainable funding are crucial components of effective interventions.
However, the study notes that challenges persist in implementing these strategies. Funding stagnation and drug and insecticide resistance pose hurdles in combating diseases like malaria. Dengue and West Nile virus infections heavily rely on community-level mosquito-control programs, which are subject to varying levels of funding and management. In the case of Lyme disease, prevention strategies include public communication to raise awareness and personal protective measures, but evidence of their effectiveness remains limited.
The development of vaccines targeting vectorborne diseases is also underway, with varying success rates. Successful vaccine development and widespread uptake have the potential to offset the adverse effects of climate change on these diseases, according to the IPCC.
