Energy poverty and indoor air pollution: a problem as old as humanity that we can end within our lifetime

About 3 billion people in the world do not have access to modern energy sources for cooking. Millions die from indoor air pollution every year.

The lack of access to modern energy sources subjects people to a life of poverty. No electricity means no refrigeration of food, no washing machine, and no light at night.

If you don’t have artificial light, your day is over at sunset. This is why the students in this photo are out on the street: they had to find a spot under a streetlight to do their homework. It’s a photo that shows both the determination of those who were born into poverty, but also the steep odds that they have to work against.

Energy poverty is so common that you can see it from space. In Sub-Saharan Africa 43% of the population do not have access to electricity. The poorest regions in the world are dark at night, as the satellite image shows.

The Earth at night – NASA1

Image of the earth at night

Students doing their homework under a streetlight in Conakry, Guinea.2

Image of teenagers studying under streetlights

But to understand one of the world’s biggest problems that comes with energy poverty we need to zoom in to what’s happening within family households around the world. More specifically, we need to take a look in the world’s kitchens. In high-income countries, people use electricity or gas to cook a meal. But 40% of the world do not have access to these clean, modern energy sources for cooking. What do they rely on instead?

The visualization below is the World Health Organization's answer.3 The so-called ‘Energy Ladder’ shows the dominant sources of household energy at different levels of income. From very low incomes on the left to high incomes on the right.

The poorest households burn wood and other biomass, like crop waste and dried dung. Those who can afford it cook and heat with charcoal or coal. Burning these solid fuels on open fires or simple stoves fills the room with smoke and toxic chemicals. These traditional energy sources expose those in the household – often women and children – to pollution levels that are far higher than in even the most polluted cities in the world.4


Indoor air pollution: what’s the problem?

The lack of modern energy comes at a terrible cost to the health of billions of people.

Millions die from diseases that are caused by air pollution within the household. Chronic exposure to pollution in the household leads to pneumonia, COPD (chronic obstructive pulmonary disease), and lung cancer.5 It is the leading risk factor of burns,6 it increases the risk of cataracts,7 and it impacts the health of babies before they are born and leads to a higher rate of stillbirths.8

Global estimates of how many people die from indoor air pollution vary. We need more data on the levels of pollution that people are exposed to; and better research on how this exposure impacts people’s health. The major studies do however all agree that the death toll is extremely high. The IHME estimates that 2.3 million people die from indoor air pollution every year. The WHO estimates the death toll to be substantially higher: 3.8 million annual deaths.9

To put this in perspective, the annual death count from HIV/AIDS is about 1 million and homicides sum up to about 400,000 globally.10

The impacts of indoor air pollution are not limited to the household. As the air escapes the home, indoor pollution is also one of the most important sources of outdoor air pollution, which kills millions more every year. We discuss this in our entry on outdoor air pollution.

History: Our ancestors have been suffering from indoor air pollution since prehistoric times

Humanity suffered and died from indoor air pollution for thousands of years. As the name ‘traditional’ fuels implies, these were the sources that our ancestors in premodern days relied on.

The use of fire by humans goes back one and a half million years.11 It kept our ancestors warm and protected; it allowed them to hunt and cook. But it also always had the negative side-effect of polluting the air that they breathed. The impact of manmade air pollution is documented in the remains of hunter-gatherers that lived in caves (close to modern-day Tel Aviv) about 400,000 years ago.12 The archeological research suggests that it came from the smoke of indoor fires used to roast meat. High levels of air pollution have also been documented in the preserved lung tissue of Egyptian mummies.13

Accounts of air pollution – indoors and outdoors – are common in the ancient world. The residents of ancient Rome referred to the periods in which their city was cloaked in thick smoke as gravioris caeli (“heavy heaven”). After leaving Rome the philosopher and statesman Seneca wrote in a letter in the year 61:

“I expect you’re keen to hear what effect it had on my health, this decision of mine to leave?

Well, no sooner had I left behind the oppressive atmosphere of the city and that reek of smoking cookers which pour out, along with a cloud of ashes, all the poisonous fumes they’ve accumulated in their interiors whenever they’re started up, than I noticed the change in my condition at once.

You can imagine how much stronger I felt after reaching my vineyards! I fairly waded into my food – talk about animals just turned out on to spring grass! So by now I am quite my old self again.

That feeling of listlessness, being bodily ill at ease and mentally inefficient, didn’t last. I’m beginning to get down to some whole-hearted work.”14

Billions still live in energy poverty

The premodern energy systems that bothered Seneca are a thing of the past for those who live in rich countries today.

But as the ‘energy ladder’ suggests, billions in low- and middle-income countries still do not have access to clean fuels. The two charts here show this.

I’m showing two charts here so we can compare what these two different measures of energy poverty tell us about the world. If you compare the data country-by-country you find that the share that has access to electricity is generally much higher than the share that has access to clean cooking fuels. We can use electricity for cooking, so why would having access to electricity not automatically mean that people have access to clean cooking technology?

It tells us that the cutoff for what it means to have ‘access to electricity’ is very low in these international statistics.15 Having access to electricity means that a household can use it for basic purposes – such as some light at night or for charging a mobile phone – but might not be able to afford electricity for energy intensive purposes, such as cooking. A family that is able to charge their mobile phones often still relies on cheaper fuels, especially wood, for cooking.

The same was true in today’s richest countries in the past. In pre-war London, 65% of households had access to electricity, but only 11% used it for cooking; the majority still relied on wood and coal.16

Globally 40% do not have access to clean fuels for cooking. Four out of ten people – that’s 3 billion people – do not have access to clean, modern energy for cooking today.

Click to open interactive version
Click to open interactive version

The reliance on wood as a source of energy contributes to environmental destruction

The use of wood as a source of energy also has a large environmental impact.

Globally about half of all wood extracted from forests is used to produce energy, mostly for cooking and heating.17 On the African continent the reliance on wood as fuel is the single most important driver of forest degradation.18 In addition to the destruction of the natural environment, the reliance on fuelwood also contributes between 2 and 7% of global greenhouse gas emissions.19

The fact that poor people have to rely on wood as a source of energy is one of the key reasons that deforestation is so rapid in poor countries – and why, on the other hand, forests in richer countries tend to expand in size.20

The modernization of the energy system – the transition to safe, low-carbon sources – is not only key to improving the health of billions of people in the world, but also to protecting the environment around us.

How can the world make progress against energy poverty and indoor air pollution?

Indoor air pollution is a global problem that is very much solvable. The benefits are especially large for women, who not only suffer the largest health consequences but are also mostly responsible for collecting and carrying the wood and biomass to their homes.21

The world is solving this problem. We see this in the chart. Strong economic growth made people around the world richer, and the death rate from indoor air pollution declined.

Globally the death toll from indoor air pollution has declined by 40% since 1990.22

Yet it’s still a massive problem. The map next to it makes this clear. In many countries this very solvable problem is still responsible for over 5% of all deaths.

Click to open interactive version
Click to open interactive version

This is one of the many reasons why growth and electrification are so important for people’s wellbeing and health.

But economic growth is often slow and with 3 billion people in energy poverty it is still a very long way to go. Based on past trends, the International Energy Agency expects that by 2030 there will still be 2.4 billion people without access to clean cooking facilities.23

Is there anything that can be done in the meantime to improve this?

Yes, even at lower incomes it is possible to move away from the most polluting fuel sources.24 China has focused on replacing the coal cookstoves that many relied on until recently and has achieved dramatic reductions in household air pollution. India achieved progress by expanding access to cleaner fuels – especially liquefied petroleum gas.

For many who live in places where modern fuels are not yet available, so-called ‘improved cook stoves’ can be an interim step towards clean cooking. Good stoves burn the fuel more efficiently and are therefore both more environmentally friendly and keep the air in the household cleaner.

Berkouwer and Dean (2019) studied the use of such stoves in Kenya in a randomized control trial to understand how to increase their adoption.25

The research documented that these stoves save households significant sums of money. They reduced fuel costs by $120 per year, equivalent to around one month of income for the average household. As the stove's market price is only $40 this implies a rate of return of 300% per year.

Poor households are aware of the benefits of these stoves. The problem, the researchers found, is that they cannot afford the upfront cost of $40 to purchase them. This makes a strong case for subsidizing this technology.

On the basis of this study, the Our World in Data team decided to offset our carbon emissions by subsidizing these cooking stoves. We cause greenhouse gas emissions from travel and to power the servers that keep the website running. A key argument for our decision to offset our emissions in this way was that these stoves have additional benefits beyond the emissions reduction. They reduce deforestation and biodiversity losses, provide economic benefits to the households, and reduce indoor air pollution.


Air pollution in the household is a problem that goes back hundreds of thousands of years. Millions of people lost their lives to it over the course of history.

Energy poverty is still the reality for around 3 billion people in the world today. What’s different from the past is that it’s now a solvable problem. What was unavoidable for the ancient Romans or the hunter-gatherers is entirely avoidable today. The millions that die today do not have to, if we find ways to end energy poverty and provide clean modern energy to everyone.

Children who want to do their homework after sunset do not have to sit under street lamps at night.

Key for making progress against energy poverty in the coming years are economic growth, increased production of clean energy, and electrification. Access to energy and clean cooking technologies would mean large benefits for environmental protection, gender equality, and for health.

Indoor air pollution is a problem as old as humanity itself. It is now possible to end it within our lifetimes.

If you want to follow us and support improved cook stoves, you can do so here:


I would like to thank Hannah Ritchie for reading drafts of this text and for her very helpful comments and ideas.


  1. This is a composite image of Europe, Africa, and the Middle East assembled from data acquired by the Suomi NPP satellite in April and October 2012. It was published by NASA. The earth at night – from all angles – can be explored via NASA’s Black Marble Project in Google Earth (as of 2021 Google Earth is showing images of the earth at night in 2016.

  2. The photo was taken by Rebecca Blackwell for the Associated Press.

    It was published by the New York Times here.

  3. This visualization is based on the Energy Ladder presented in WHO (2006) – Fuel for life: household energy and health. Online here.

    Clean fuels are those that do not cause harmful levels of emissions within the household. Among those fuels that are considered in the ‘Energy Ladder’ these are all fuels except the solid fuels and biomass.

    On clean fuels see:

    It would be possible to add specific technologies (rather than just fuels) to the Energy Ladder, in such an extended version one might consider to include improved biomass cookstoves (ICS) and solar cookers.

    An improved biomass cookstove (ICS) describes a stove with higher efficiency or lower emissions than a traditional stove. The WHO however cautions:  “Most ICS models do not meet WHO Guidelines, but offer some benefits and can be used as transitional solutions.Further innovation, research and investment may indeed produce affordable and widely available biomass stoves that meet the WHO Guidelines levels.” Further below in this text I discuss some of the benefits of high-quality ICS.Solar cookers are not as widely adopted as the fuels considered here and are not included in the Energy Ladder published by the WHO.

  4. WHO (2018) – Fact Sheet - Household air pollution and health

    Junfeng (Jim) Zhang, Kirk R Smith (2003) – Indoor air pollution: a global health concern, British Medical Bulletin, Volume 68, Issue 1, December 2003, Pages 209–225,

    The pollutants encompass a wide range of different compounds, the most important ones being fine particulate matter (PM2.5), black carbon, and carbon monoxide.

    WHO 2006) reports: “Burning solid fuels produces extremely high levels of indoor air pollution: typical 24-hour levels of PM10 in biomass-using homes in Africa, Asia or Latin America range from 300 to 3000 micrograms per cubic metre (µg/m3). Peaks during cooking may be as high as 10 000 µg/m3. By comparison, the United States Environmental Protection Agency has set the standard for annual mean PM10 levels in outdoor air at 50 µg/m3; the annual mean PM10 limit agreed by the European Union is 40 µg/m3.” –– WHO (2006) – Fuel for life: household energy and health. Online here.

    Delhi is one of the cities with the worst air quality in recent years. Wikipedia has an overview of measurements on their site Air pollution in Delhi and daily data on the air quality in Delhi can be found here.

    For a comparison of indoor air pollution levels from different energy sources see Shupler, M., Hystad, P., Birch, A., Miller-Lionberg, D., Jeronimo, M., Arku, R. E., Chu, Y. L., Mushtaha, M., Heenan, L., Rangarajan, S., Seron, P., Lanas, F., Cazor, F., Lopez-Jaramillo, P., Camacho, P. A., Perez, M., Yeates, K., West, N., Ncube, T., … Brauer, M. (2020) – Household and personal air pollution exposure measurements from 120 communities in eight countries: Results from the PURE-AIR study. In The Lancet Planetary Health, 4(10), e451–e462.

  5. For more information on the relevant research see the final section of our entry on indoor air pollution

    And for an overview of the health consequences of indoor air pollution see Bruce, N., Perez-Padilla, R., & Albalak, R. (2000) – Indoor air pollution in developing countries: a major environmental and public health challenge. In Bulletin of the World Health Organization, 78(9), 1078–1092.

  6. Cooking on an open fire or with simple, poorly designed stoves is a leading cause of burns, especially among women and children in poorer countries. See World Health Organization (2018) – Fact sheets: Burns

  7. Indoor air pollution increases the risk of cataracts. See: Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H et al. (2012) – A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 380:2224-226023245609.

  8. On the impact of indoor air pollution on adverse pregnancy outcomes (including stillbirth) see Pope DP, Mishra V, Thompson L, Siddiqui AR, Rehfuess EA, Weber Met al. (2010) – Risk of low birth weight and stillbirth associated with indoor air pollution from solid fuel use in developing countries. Epidemiol Rev 32:70-8120378629.

  9. These are the latest estimates at the time of writing in June 2021. In 2018 (the latest available WHO publication) the WHO estimated 3.8 million deaths. WHO (2018) – Fact Sheet - Household air pollution and health. This data refers to 2016 (as indicated here).

    The results of the Global Burden of Disease study by the IHME can be found in their scientific publications (usually published in The Lancet) and the specific results on the impact of air pollution can also be found in the annual report ‘State of Global Air’. This report is published jointly by the IHME and the Health Effects Institute.Health Effects Institute (2020) – State of Global Air 2020. Special Report. Boston, MA.

    • 1990: 4,358,000 deaths due to household air pollution from solid fuels
    • 2019: 2,314,000 deaths due to household air pollution from solid fuels

    Because the IHME data is more recent and updated annually we rely mostly on IHME data in our work on indoor air pollution.

    We are unfortunately not aware of any detailed explanation for the large discrepancy between these two estimates.

  10. These are rounded numbers for 2017 from the IHME. For details see our entry on causes of death.

  11. For an overview see Gowlett, J. a. J. (2016) – The discovery of fire by humans: A long and convoluted process. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1696), 20150164.

  12. Ran Barkai, Jordi Rosell, Ruth Blasco, and Avi Gopher (2017) – Fire for a Reason: Barbecue at Middle Pleistocene Qesem Cave, Israel. In Current Anthropology; Volume 58, Number S16, August 2017, Fire and the Genus Homo.

    An overview of the team’s research in Qesem cave can be found in 400,000-year-old dental tartar provides earliest evidence of manmade pollution in EurekAlert.

  13. Owen Jarus – Egyptian Mummies Hold Clues of Ancient Air Pollution. In LiveScience.

  14. Seneca – Letters from a Stoic: Epistulae Morales Ad Lucilium. In Letter CIV. Partly online here.

  15. See Raising Global Energy Ambitions: The 1,000 kWh Modern Energy Minimum and IEA (2020) – Defining energy access: 2020 methodology, IEA, Paris.

  16. Fouquet, R. (2011) – Long run trends in energy-related external costs. Ecological Economics, 70(12), 2380–2389.

    This practice is called ‘fuel stacking’.

    There are many reasons for that, a large one is that cooking is very energy-intensive and that poor households do have access to sufficient electrical energy to rely on it for such energy-intensive uses. There can also be other practical considerations, for example that a modern stove cannot accommodate a pot that is large enough to cook for the whole family. Or that people prefer the taste of food cooked on a wood or a charcoal stove.

  17. FAO (2017) – The Charcoal Transition. In FAO – Wood Energy - Basic Knowledge the authors write “The annual removal of wood worldwide was estimated at about 3.7 billion m3, of which 1.87 billion m3 was used as fuel.

  18. FAO and UNEP. 2020. The State of the World’s Forests 2020. Forests, biodiversity and people. Rome.

    The same report also reports that an estimated 880 million people worldwide are collecting fuelwood or producing charcoal with it

  19. According to the 2017 FAO publication The Charcoal Transition the use of firewood and charcoal contributes between 1-2.4 gigatons of CO2-equivalent greenhouse gases annually, which is 2-7% of global anthropogenic emissions.

  20. On this see the linked work on Our World in Data on deforestation and also Rufus D Edwards, Smith KR, Zhang J, Ma Y. (2004) – Implications of changes in household stoves and fuel use in China. In Energy Policy 32:395-411.

  21. WHO (2018) – Fact Sheet - Household air pollution and health

    Dasgupta, Susmita; Huq, Mainul; Khaliquzzaman, M.; Pandey, Kiran; Wheeler, David (2004) – Who Suffers from Indoor Air Pollution? Evidence from Bangladesh. Policy Research Working Paper; No.3428. World Bank.

    Shupler et al (2020) on the other hand, report only small differences in the exposure between men and women.Shupler, M., Hystad, P., Birch, A., Miller-Lionberg, D., Jeronimo, M., Arku, R. E., Chu, Y. L., Mushtaha, M., Heenan, L., Rangarajan, S., Seron, P., Lanas, F., Cazor, F., Lopez-Jaramillo, P., Camacho, P. A., Perez, M., Yeates, K., West, N., Ncube, T., … Brauer, M. (2020) – Household and personal air pollution exposure measurements from 120 communities in eight countries: Results from the PURE-AIR study. In The Lancet Planetary Health, 4(10), e451–e462.

  22. This is according to the figures from the IHME. In 1990 – just a generation ago – 2.7 million people died from indoor air pollution. Since then the number of deaths has fallen to 1.6 million.

  23. This is according to their Stated Policies Scenario, or STEPS, scenario which is taking into account current and announced policies. It is also taking into account a reversal in progress in 2020 and 2021 due to the pandemic.

  24. See Health Effects Institute (2020) – State of Global Air 2020. Special Report. Boston, MA.

  25. Berkouwer, S. B., & Dean, J. T. (2019). Credit and attention in the adoption of profitable energy efficient technologies in Kenya. UC Berkeley CEGA Working Paper. Available at

    A short post about this study by one of the authors is published on the World Bank blog.

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Max Roser (2021) - “Energy poverty and indoor air pollution: a problem as old as humanity that we can end within our lifetime” Published online at Retrieved from: '' [Online Resource]

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    author = {Max Roser},
    title = {Energy poverty and indoor air pollution: a problem as old as humanity that we can end within our lifetime},
    journal = {Our World in Data},
    year = {2021},
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