Burning fossil fuels like oil, gas, and coal releases massive amounts of carbon dioxide and methane, which trap more heat than usual in the atmosphere. As global demand for electricity is shooting up, burning more fossil fuels has been resulting in more greenhouse emissions and more heat getting trapped in the lower atmosphere.
To date, scientists have conducted over 152 studies to determine how human-induced climate change is making extreme weather events like heat waves far more likely or severe than ever before. More than 90% of those studies have concluded that human-induced climate change is making heat waves more frequent, severe, and longer over the last 20 years.
While these frequent heatwaves have been wreaking havoc on public health, a recent British Medical Journal study reported urban green spaces play a crucial role in lowering the rates of heat-related illnesses and deaths.
“As consequences of urbanization and climate change, environmental alterations such as the urban heat island effect and other extreme weather phenomena are increasingly evident. Compounding these issues are escalating temperatures, primarily fuelled by rapid urbanization,” the researchers wrote in the study.
“Counteracting these global challenges—encompassing climate change, health inequity, and sustainable urbanization—green areas or urban vegetation are critical,” they added.
During heatwaves, children and the elderly are the most vulnerable to suffering from heat exhaustion, and dehydration, and in some cases, the adverse impacts of high temperatures could even end up becoming fatal. “Children’s developing bodies, older adults’ decreased physiological resilience, and compromised health status of those with chronic conditions make these groups particularly susceptible to heat stress and heat-related illnesses. The exacerbated vulnerability of these populations highlights the critical need for targeted urban planning and public health strategies,” the researchers explained.
Urban green spaces like parks and tree-lined streets act as a buffer from the relentless summer heat and protect residents from being directly exposed to high temperatures. To further investigate how effective green spaces can be in preventing heat-related illnesses and deaths, the authors reviewed 12 studies conducted in Hong Kong, Vietnam, Japan, South Korea, Portugal, Australia, and the United States.
The authors highlighted that although their study mainly focused on high-income countries, the impacts of extremely high temperatures should be studied further in low and middle-income countries. “People living in low-resource settings are particularly susceptible, as outdoor manual labor is more common and adaptation to climate change is costly. Moreover, they are at a higher risk from heat waves due to shortages of electricity during summer months, this further disadvantages those who cannot afford alternative sources of power,” they noted.
They referred to a devastating 2015 heatwave in Karachi, Pakistan, where 65,000 people were rushed to the hospital with heat-related symptoms. “Heat-related deaths are also reported in countries such as India and Bangladesh where people are exposed to extreme heat from climate change and heat island effects,” the authors added. “Studies have found that areas with more green space have lower rates of heat-related morbidity and mortality compared to areas with less green space. Moreover, urban greenery can also have a positive impact on mental health and well-being, which can also contribute to reducing the negative health effects of high temperatures.”