Heat Waves Hit the Poor Hardest

By Mojtaba Sadegh, John Abatzoglou, Mohammad Reza Alizadeh 24 October, 2022

Heatwaves are among the deadliest disasters and poorer countries will be 2-5x more exposed to them by 2060, which risks $ billions. Sadegh, Abatzoglou & Alizadeh share more key findings from their research

Heatwaves are among the deadliest climate & weather-related disasters, already 30% of the world live in deadly heat & humidity levels at least 20 days/ year
Poorer countries will be 2-5x more exposed to heatwaves by 2060; wealthy nations can buffer risks by investing while poorest quarter lags in adapting to heat by 15 years
Heatwave days are increasing & seasons are getting longer; international assistance is key as economic loss in developing countries could reach $580bn/ year by 2030

This article is republished from The Conversation (under a Creative Commons license). Read the original article, “Heat waves hit the poor hardest – a new study calculates the rising impact on those least able to adapt to the warming climate”, published on 10 February 2022 here.

Spend time in a developing country during a heat wave and it quickly becomes clear why poorer nations face some of the greatest risks from climate change. Most homes don’t have air conditioning, and even health clinics can get overheated.

These countries tend to be in the hottest parts of world, and their risk of dangerous heat waves is rising as the planet warms.

Poorer countries will be 2-5x more exposed to heatwaves by 2060

In a new study, our team of climate scientists, economists and engineers found that the poorest parts of the world are likely to be two to five times more exposed to heat waves than richer countries by the 2060s. By the end of the century, the lowest-income quarter of the global population’s heat exposure will almost match that of the entire rest of the world.

Capacity to adapt to rising heat is crucial

Heat waves are often assessed by how frequent or intense they are, but vulnerability involves more than that.

A key factor in the amount of harm heat waves cause is people’s capacity to adapt with measures like cooling technology and the power to run it.

Wealthy countries can buffer risks by investing in climate adaptation

To assess how heat wave exposure is changing, we analyzed heat waves around the world over the past 40 years and then used climate models to project ahead. Importantly, we also incorporated estimates of countries’ ability to adapt to rising temperatures and lower their heat exposure risk.

We found that while wealthy countries can buffer their risk by rapidly investing in measures to adapt to climate change, the poorest quarter of the world – areas likely to be slower to adapt – will face escalating heat risk.

Poverty slows the ability to adapt to rising heat

Heat waves are among the deadliest climate and weather-related disasters, and they can be destructive to crops, livestock and infrastructure. Currently, about 30% of the global population lives in areas where heat and humidity levels can be deadly on at least 20 days a year, studies show, and the risk is rising.

Heatwaves are among the deadliest climate & weather-related disasters…

…already 30% of the world live in deadly heat & humidity levels at least 20 days/ year

Adaptation measures, such as cooling centers, home-cooling technology, urban planning and designs focused on reducing heat, can lower a population’s heat exposure impact. However, a country’s ability to implement adaptation measures generally depends on its financial resources, governance, culture and knowledge. Poverty affects each. Many developing countries struggle to provide basic services let alone protections from escalating disasters in a warmer future.

The compounding effects of economic, institutional and political factors cause a lag in low-income countries’ ability to adapt to the changing climate.

Poorest quarter of the world lags the wealthiest in adapting to heat by 15 years

We estimate that the poorest quarter of the world lags the wealthiest in adapting to rising temperatures by about 15 years on average. This estimate is based on the pace of preparation and support for adaptation plans described in the U.N. Environment Program’s Adaptation Gap Report. The actual lag will vary because of wealth inequities, but that estimate provides a broad picture of the rising risks.

Heat risk is up globally, but more in poor regions

Looking back over recent decades, we found a 60% increase in heat wave days in the 2010s compared with the 1980s. We defined a heat wave as extreme daily temperatures above the 97th percentile for the area, for at least three consecutive days.

We also found that heat wave seasons were getting longer, with more frequent early- and late-season heat waves that can increase heat-related deaths.

60% increase in heat wave days in 2010 compared to 1980s & seasons are getting longer

Our analysis showed that people’s average heat wave exposure in the poorest quarter of the world during the 2010s was more than 40% greater than in the wealthiest quarter – roughly 2.4 billion person-days of heat wave exposure per year compared with 1.7 billion. A person-day is the number of people exposed to the heat wave times the number of days.

This heat wave risk in poor countries has often been overlooked by the developed world, in part because heat deaths aren’t consistently tracked in many countries.

By the 2030s, we project that the lowest-income quarter of the world’s population will face 12.3 billion person-days of heat wave exposure, compared with 15.3 billion for the rest of the world combined.

By the 2090s, we estimated it will reach 19.8 billion person-days of heat wave exposure in the poorest quarter, almost as much heat wave exposure as the three higher-income quarters together.

Climate justice and future needs

The results provide more evidence that investing in adaptation worldwide will be crucial to avoid climate-driven human disasters.

The world’s wealthiest nations, which have produced the lion’s share of greenhouse gases driving climate change, promised over a decade ago to direct US$100 billion annually by 2020 to help the poor countries adapt to climate change and mitigate its effects. Some of that money is flowing, but wealthy countries haven’t met the goal yet.

International assistance is key as economic loss in developing countries could reach $580bn/ year by 2030

Studies meanwhile have estimated that economic loss from future climate damage in developing countries will reach between $290 billion and $580 billion a year by 2030 and continue to escalate.

Increasing international assistance can help poorer countries adapt to the harm caused by climate change. Companies and innovators can also play an important role by developing low-cost microgrid electricity and cooling technology to help poor countries survive escalating heat waves.

Further Reading

  • Rising Temperatures, Melting Ratings – 63 countries will suffer climate-induced rating downgrades in the world’s first climate smart sovereign rating simulation. More key findings from the simulation creators Dr Patrycja Klusak, Dr Matthew Agarwala, Matt Burke, Dr Moritz Kraemer & Dr Kamiar Mohaddes
  • Triple Whammy Hit for HK’s Poor; the Rich can Escape Rising Seas – Buyer beware! You could lose your homes & savings from rising seas. More so if you are poor in Hong Kong. CWR’s Dr CT Low & Debra Tan share 3 hits + 3 actions to close the gap on climate injustice
  • Adapting To Climate Change – Like it or not, climate impacts are getting increasingly ‘up close & personal’ yet adaptation finance is lagging. Banks & Investors should get on top of it as it makes business sense, suggest BNP’s Chaoni Huang & Jonathan Ho
  • Climate Resilience In Asian Cities – Nature-Based Solutions can help with Asia’s significant climate vulnerability as Vivekanandham Sindhamani and Nanco Dolman from Royal HaskoningDHV show
  • Where Are We On Ice Tipping Points Post COP26? – If we are not careful, we could change weather as we know it – what are these tipping points? How high will seas rise? What will happen to mountain glaciers? See our review of the report State of Cryosphere 2021 for answers

More on latest 

  • Rivers are Running Dry Today – Rivers are our lifelines; they support cities, food & economies for centuries. This summer they were tested with severe drought/floods – will they fail? CWR’s Tan & Lam dive into challenges facing 5 major river basins that are the industrial/agricultural heartlands for China, Pakistan, US and Europe.
  • Companies: It’s Survival of the Fittest in A Changing Climate – Riskier and costlier water and climate-related water risks are drastically reshaping the operating environment, even for leading companies. See what companies need to do to survive with CWR’s McGregor
  • China’s Growing Water Risk Factor – China is especially vulnerable to water-related climate risks but that also means increasing capacity for adaptation for which it has big ambitions. Moore, Director of China Programs & Strategic Initiatives at UoP, expands
  • Building Too Close to the Water. It’s Ridiculous! – Reeling from climate disasters, it’s time for managed retreats & buyouts in Australia. O’Donnell, Honorary Associate Professor at ANU, expands
  • A Climate-Ready Northern Metropolis – Seizing the opportunity, Loh, Chief Development Strategist at HKUST, launched the ‘Sustainable Northern Metropolis’ project. We sit down with Loh to talk about the project’s vision, risks, opportunities for HK to climateproof with Shenzhen & more
Mojtaba Sadegh
Author: Mojtaba Sadegh
Moji’s research is focused on risk and impact analysis of different climatic and weather extreme events, including wildfires, droughts, heatwaves, and floods.
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John Abatzoglou
Author: John Abatzoglou
Professor Abatzoglou is interested in the hows and whys of climate and weather, and also the so whats. His lab's work spans many topics - from addressing questions on climate variability, to understanding climate impacts on natural resources, to developing climate datasets and tools.
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Mohammad Reza Alizadeh
Author: Mohammad Reza Alizadeh
Mohammad Reza Alizadeh is a PhD Candidate in the Department of Bioresource Engineering at McGill University. His principal research objective is to bridge the gap between climatology, hydrology, remote sensing, and machine learning, towards addressing critical global environmental issues. Mr. Alizadeh’s research interests extend to compound climate extremes including droughts, heatwaves, floods and wildfires.
Read more from Mohammad Reza Alizadeh →