Article | The Heat is On: Invisible, Unprecedented, and Screaming for New Solutions
The world is experiencing unprecedented warming. According to NOAA's 2023 climate report, the combined land and ocean temperature has increased at an average rate of 0.11° Fahrenheit (0.06° Celsius) per decade since 1850, totaling about 2° F. This rate has accelerated significantly since 1982, with a current increase of 0.36° F (0.20° C) per decade. The India Meteorological Department’s (IMD) summer outlook indicates that temperatures across the entire peninsula will be well above normal this year. This is particularly alarming as all Himalayan mountain states are expected to experience abnormal heat, supporting the adage, "When the Himalayas are sick, the rest of the country cannot remain healthy."
Cascading Environmental Impacts
This rise in temperature introduces significant livability risks and is likely to trigger a series of environmental impacts, including extensive cloud bursts, glacial lake outbursts, flash floods, and landslides. The creeping effects of water and heat stress on crops are anticipated to deeply impact livelihoods, commodity prices, and trade.
The Broad and Nightly Impact of Heat
The IMD’s summer outlook also highlights that minimum temperatures will be higher than normal, leading to intensified heat during nights—a condition that often results in a spike in heat-related deaths. These fatalities occur predominantly on the hottest nights rather than during the hottest days. The forecast for the summer of 2024 predicts longer heatwave durations, which have increased from an average of 8-10 days to nearly 20 days this year.
Long-term Projections and Human Impact
Despite ongoing climate actions, projections forewarn that heatwave durations could extend up to 50 days between 2041 and 2070, with peak temperatures exceeding 50º C. This scenario, which may seem distant, is a reality awaiting today’s primary school children who, by then, will be adults attempting to build families in potentially unlivable cities.
Hazardous Humidity
Transitioning from the dry to humid months, heat assumes a more hazardous form. The IMD’s new heat index shows that a 49º C temperature at 10% relative humidity is less harmful than a 35º C temperature at 80% humidity. It’s unsafe to assume that a lower temperature of 35º C marks the end of heat-induced health impacts, as the body struggles to cool itself in such conditions.
Visibility of Heat Impacts
Traditionally, discussions on extreme heat have focused on heatstroke, a potentially fatal condition difficult to pinpoint as most heat deaths are reported under less specific causes like cardiac arrests. More widespread than heatstroke is heat stress, which makes individuals feel unwell and reduces their productivity, yet goes largely unnoticed and untreated.
Heat Doesn't Walk Alone
Urban fires often spike during the dry season, triggered by electrical short circuits on overloaded power infrastructure or by dry combustible materials. Wildfires, ignited by the tens of thousands, spread widely and burn for months until extinguished by rain, destroying biodiversity and worsening air pollution.
Water Scarcity and Soil Hydrophobia
Heat increases water demand while supplies are at their lowest. Surprisingly, extreme heat makes soil hydrophobic, reducing its water absorption and leading to greater runoff and potential floods when it rains suddenly after a period of extreme heat.
Human Contributions and Urban Heat
Human activities have exacerbated the issue by creating heat islands through urban development, replacing soft soil surfaces, water bodies, and green spaces with concrete and glass. Cities are notably hotter than the countryside, especially densely populated, low-income urban areas.
Anticipate, Adapt, and Cool Down
We must learn to live with heat through a multi-pronged approach involving anticipation, adaptation, and the development of cooling strategies. Enhanced forecasting, strategic urban planning, and the development of cooling technologies that do not contribute to planetary heating are crucial. High-resolution geospatial data and AI models now aid in identifying heat impacts rapidly, offering new tools for immediate action.
As the world continues to warm, informed and timely actions are essential. We have no time to rest.