When extreme heat is upon us
“TODAY, we officially declare the start of the Philippine summer based on the analysis of the latest forecast,” declared the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) on March 22.
Due to El Niño, this summer could be “one of the warmest dry seasons” ever recorded in the country with temperatures rising as high as 40 degrees Celsius, particularly in Region 2 (Cagayan Valley).
The heat index, which is the temperature that the human body feels, may reach the “danger” (42 C to 512 C) and “extreme danger” (52 C and beyond) levels for the next two months. Pagasa’s website projected a “danger” level for Metro Manila at the beginning of this month.
According to the International Public Opinion on Climate Change-Extreme Weather and Vulnerability Report, 33 percent of Filipinos experienced a long period of unusually hot weather. A Yale Program on Climate Change Communication report revealed that nine out of 10 Filipinos (88 percent) attributed this unusually hot weather to climate change.
Climate change leads to an overall increase in global temperatures. In February 2024, the European climate service Copernicus announced that “the world’s average temperatures have been higher than the 1.5 degrees Celsius global warming limit for the 12 months in a row for the first time since records began.”
The Intergovernmental Panel on Climate Change said that “humaninduced greenhouse gas emissions have led to an increased frequency and/or intensity of some weather and climate extremes since preindustrial time, in particular for temperature extremes.” It said that the “hot extreme events” would have been “extremely unlikely to occur without human influence.”
This increasing temperature means that heat waves will become more frequent, intense and prolonged. Those that were considered extreme heat events in the past will become more common occurrences. Climate change not only raises average temperatures but also amplifies temperature extremes. Heat waves become hotter than they would have been without climate change, pushing temperatures to record-breaking levels.
When climate change interacts with urbanization, it will exacerbate extreme heat in cities. Urban areas tend to trap heat, leading to higher temperatures than surrounding rural areas — a phenomenon known as the urban heat island effect. As cities grow and temperatures rise due to climate change, urban populations become more vulnerable to extreme heat. Lack of green spaces, limited access to cooling facilities and higher concentrations of heatabsorbing materials contribute to increased heat stress in cities.
Health impact
Extreme heat has profound effects on ecosystems, including stress on plants and animals, altered habitats and increased wildfire risk. Climate change worsens these impacts, resulting in changes in species distributions, loss of biodiversity and disruption of ecosystems. These effects have far-reaching social and economic consequences, including impacts on agriculture, infrastructure, energy demand and labor productivity. Climate change magnifies these risks, posing challenges for adaptation and resilience-building efforts.
According to The State of Southeast Asia 2024 Report, which was released last April 2, Filipinos consider climate change and intense weather events, such as extreme heat, as their second-biggest challenge. Extreme heat can have significant impacts on human health, well-being and productivity. It can cause heat-related illnesses such as heat exhaustion, heat stroke, heat cramps and heat rash. These conditions can range from mild to severe and, if not treated, can be life-threatening.
Extreme heat can also worsen preexisting health conditions like cardiovascular, respiratory and diabetes diseases. Additionally, it can exacerbate mental health conditions, leading to increased hospitalizations and emergency room visits. It can also cause increased sweating and fluid loss, resulting in dehydration and electrolyte imbalances. These conditions can lead to weakness, dizziness, confusion, and, in severe cases, organ failure.
When extreme heat reaches the “extreme danger” level, it can increase mortality rates, especially among vulnerable populations such as the elderly, young children, people with chronic illnesses and those living in poverty or without access to cooling facilities.
The lack of sufficient ventilation in public schools, as indicated by the presence of only one to two electric fans, exposes the education system’s unpreparedness for a heat crisis. According to 46 percent of Metro Manila teachers, this condition is prevalent. An Alliance of Concerned TeachersNational Capital Region survey also revealed that “87 percent of teachers believe that the intense heat in classrooms affects students’ ability to concentrate.”
Extreme heat can disrupt daily activities and routines, reducing outdoor recreation, decreasing work and productivity, and increasing reliance on air-conditioning and cooling systems. This has social, economic and environmental consequences.
Our current situation requires comprehensive strategies to mitigate climate change, adapt to changing conditions and protect vulnerable populations. This includes reducing greenhouse gas emissions, improving urban planning and design to mitigate the urban heat island effect, implementing early warning systems and heat wave response plans, enhancing public health and emergency preparedness measures, and community outreach and education initiatives to raise awareness and promote resilience.
The author (ludwig.federigan@gmail.com) is the executive director of the Young Environmental Forum and a nonresident fellow of Stratbase ADR Institute. He completed a climate change and development course at the University of East Anglia (UK) and an executive program on sustainability leadership at Yale University (USA).