Change for the worse

The world is facing an escalating health crisis fuelled by climate change, manifesting in heat waves, floods, and rising temperatures. These environmental changes are not only causing immediate health impacts but are also creating ideal conditions for the spread of various pathogens, including bacteria, viruses, fungi, and protozoa. The consequences of human-induced climate change are already apparent, with hotter temperatures, rising sea levels, and more frequent and severe storms. A significant analysis published in the journal Nature Climate Change highlights that climate change has increased the risk of nearly 60% of all known infectious diseases. These include tick- and mosquito-borne diseases like Lyme disease and dengue, as well as various food- and waterborne infections Heat waves are particularly concerning. They lead to heat exhaustion, heat stroke, and other heat-related illnesses, especially in vulnerable populations such as the elderly, young children, and people with pre-existing health conditions. The impacts on human health are profound, with severe heat waves leading to heat cramps, heat exhaustion, heat stress, heat stroke, and even death. Additionally, heat waves exacerbate air pollution and can cause power outages due to increased demand for air conditioning.The agricultural sector also suffers greatly during heat waves. High temperatures can lead to a significant reduction in crop yields and reproductive failure in many crops, negatively impacting food security. Children, the elderly, and those with existing health issues such as heart, respiratory, kidney diseases, and psychiatric disorders are particularly at risk.One of the subtler yet insidious impacts of climate change is on the spread of diseases. The changing climate affects the mosquito that carries a virus or the pathogenic bacteria on a piece of fruit. A growing body of studies shows the link between climate change and the increasing threat of zoonotic diseases—those transmitted from animals to humans. In India, for example, cases of dengue fever have soared due to longer rainy seasons and more frequent and severe floods, allowing mosquitoes to thrive. The outbreak of other diseases, such as those spread through vector-borne transmission, is directly linked to the changing climate. Dengue, among vector-borne diseases, has become endemic in more regions of 129 countries, making its presence steady and predictable. These countries, inhabited by half of the world’s population—nearly four billion people—are at risk of contracting the disease. Although most dengue cases are not fatal, those with comorbidities face a severe risk of death. The spread of dengue is now even seen in places where it was previously unknown, such as Brazil, which reported nearly two million cases in August 2022, and Japan, which in 2014 suffered its first dengue outbreak in seventy years. Researchers warn that with climate change, these outbreaks could become more frequent. The mortality rate due to heat waves is higher than any other natural hazard in different parts of the world. Besides human health, heat waves negatively impact agriculture and ecosystems by damaging crops and causing droughts. The cumulative effects of climate change on health and agriculture underscore the urgent need for comprehensive climate action to mitigate these growing threats.In conclusion, the intertwined issues of climate change and health require immediate and sustained attention. Addressing these challenges is critical to safeguarding human health and ensuring a sustainable future for generations to come.