Article de Stéphanie Fonseca Johann (EnvIM 2019)


Being in quarantine far from my family and hometown, my favorite activity during the COVID-19 lock down was to cook. Electric stove on, traditional Brazilian samba music playing, flavors would come out from the pan and fill the kitchen with a smell that made me feel home and safe.
Often considered by many as an act of love, as an art or a way to meditate, cooking has the power to make us travel inside our kitchens through their mix of tastes and flavors. In fact, cooking constitutes an important trait of any human culture. In his book “Catching Fire: How Cooking Made Us Human”, Richard Wrangham, a professor of biological anthropology at Harvard University affirms how cooking is what makes us human. That is because cooking aliments with fire increases the number of calories ingested while decreasing the energy cost of digestion. Through that, more metabolic energy has become available, allowing for the development of bigger brains and humans have then had more spare time to dedicate to hunt and social activities.(Shaw, 2009)
Sadly, until today for almost 40% of global population, cooking is also a silent danger. Close to 3 billion people cook by burning solid biomass (wood or charcoal for example) in open fires, most of the time inside poor ventilated houses, whereby inhaling daily harmful products of incomplete combustion (Putti et al., 2015). Being responsible for 4.3 million deaths every year, this rudimentary practice also reflects and digs gender inequality and contributes non-negligibly to climate change.



As shown in figure 1, open fire biomass cooking (OFBC) dependency is mostly located in low and middle-income areas such as developing Asia, Sub-Saharan and Central African countries and Latin America. (IEA, 2019)

Figure 1: (a) Chulha: traditional open fire cook stove in India Source: IASToppers, n.d. (b) Population relying on biomass - 2018 - Source: IEA SDG 7- Data and Projections
Figure 1: (a) Chulha: traditional open fire cook stove in India Source: IASToppers, n.d. (b) Population relying on biomass – 2018 – Source: IEA SDG 7- Data and Projections

An estimation of 4.3 million premature deaths per year are caused by exposure to household air pollution (HAP) linked with open fire biomass cooking (OFBC). (WHO, 2016) This more than HIV, tuberculosis and malaria deaths all combined (Lee et al., 2013) and translates into a direct cost of up to $400 billion, or 0.5% of global GDP. (Putti et al., 2015).

Figure 2: Household Air Pollution Health Impact - source: WHO
Figure 2: Household Air Pollution Health Impact – source: WHO

HAP contains small particulate matter and pollutants that enters through the airways and lungs degrading the immune system and decreasing the oxygen-carrying capacity of the blood. Thus, exposure to HAP is source of many heart, lung and respiratory diseases. Pneumonia and ischemic heart disease are responsible for 27% of total HAP exposure’s deaths each year, followed by obstructive pulmonary diseases and strokes that account for 20% and 18% of deaths respectively (WHO, 2018), as illustrated by figure (2).



After buying your ingredients, how much time do you spend cooking daily? How much time do you need to light your stove? A study conducted by the The World Bank (2014) in Sub-saharian Africa suggests daily individual wood gathering can take from 1 hour in Kenya up to 5 hours in Sierra Leone, as shown by figure (3). Aside from fuel collection, a significant amount of time is dedicated daily to fuel preparation, in case of wood, and cooking, since cooking aliments in rudimentary conditions requires more time.

Figure 3: Wood collection time (hours/day/household). Source: The World Bank 2014
Figure 3: Wood collection time (hours/day/household). Source: The World Bank 2014

Hence, on top of the direct cost of diseases provoked by HAP, the opportunity cost of time lost during fuel collection and cooking should then be added to the total cost of OFBC. In order to estimate this indirect cost, the total amount of time spent into collection and cooking should be moderated by the income generating opportunity level of each region. If up to 35% of this time was to be reverted in remunerated work, studies estimates an indirect cost of USD 5 to 30 billion. (Putti et al., 2015)



Due to their greater involvement in cooking daily related activities, especially in poor countries, women and children, they keep close, are disproportionality affected OFBC’s harms.
The greater involvement of women in cooking activities in countries using OFBC was demonstrated by Putti et al. (2015) as shown in figure (4). In Nepal, for example, while women spend more than 2 hours per day collecting firewood, men spend only 50 min. Women in the same country will spend 2 hours per day cooking and preparing food, a duration that is 7 times longer than for men.

Figure 4: Firewood Collection and Cooking Time by Gender. Source: Putti et al. 2015
Figure 4: Firewood Collection and Cooking Time by Gender. Source: Putti et al. 2015

Thus, amongst the 4.3 million deaths per year due to HAP exposure, 60% are women and children. To reinforce this trend, Putti et al. (2015) brings the figure below that illustrates the striking difference between the number of women and men suffering from respiratory illness and eye irritation.

Figure 5: Gender-Disaggregated Health Impacts. Source: Putti et al. (2015)
Figure 5: Gender-Disaggregated Health Impacts. Source: Putti et al. (2015)

Aside from HAP related diseases, women walk up to 10 kilometers (per trip) carrying in average 20 kilograms of wood. Evidences indicates that physical injuries from heavy load and due to accidents are significantly higher for women. As if this would not be enough, women and girls are exposed to sexual violence while gathering cooking fuels. Reports of rapes are particularly common in countries that holds refugee camps such as Kenya, Chad, Ethiopia and RDC (Putti et al., 2015)
At a very young age, girls are daily involved in the never ending task of gathering fuel and cooking. As seen before, in some countries the complete tasks can require more than 5 hours of girls’ attention, taking them away from school and leisure, thus contributing to the sustaining of gender inequalities. When adults, this responsibility prevent women to participate in the household’s income generation, stripping out their chance to help raising their family out of poverty and reinforcing patriarchal system.



Close to 3 billion people, almost 40% of global population, use inefficient cook stoves to burn millions tones of solid biomass per year to feed themselves. Rudimentary cook stoves burn solid biomass by incomplete combustion. This phenomenon is at the origin of household air pollution (HAP) production. The main components of HAP are carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and particulate matters called black-carbon. CO2, N2O and CH4 are well-known greenhouse gas that contribute to climate change. As a particulate matter and short-lived climate-forcing, black carbon has also an important role to play in climate change. (Goldemberg et al., 2018)
OFBC and charcoal production are estimated to produce 0.5-1.2 billions metric tons of CO2equivalent, representing 1.5-3% of global emission. OFBC are also source of 25% of global black carbon emission. An uncertainty remains regarding estimation of CO2 emissions due to the unknown level of renewable harvested wood used for OFBC. Indeed, to be accounted as climate changers, gases should have a greenhouse effect, meaning they should create a disequilibrium in the quantity of radiation absorbed and emitted by Earth. However, combustion of renewable harvested wood is re-absorbed by biomass, thus not creating climate forcing. (Putti et al., 2015)
Black carbon (BC), commonly known as soot, and categorized as aerosol, is the most-strongly absorbent of light among particulate matter PM2.5. BC is considered a short-lived climate pollutant (SLPC), which according to the IPCC are “pollutant emissions that have a warming influence on climate and have a relatively short lifetime in the atmosphere (a few days to a few decades)”. (IPCC, 2014) While CO2’s lifetime in atmosphere is up to thousand years, BC’s lasts only a few days. Its role on global warming is still controversial. As mentioned by Hawken in his book Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming, for some researchers BC would be the second largest driver of climate change, after CO2. For other experts, black carbon climate forcing impact might be mainly offset by the cooling effect of organic aerosol emitted simultaneously by combustion of solid fuels. (Putti et al., 2015)
Nevertheless, it is certain that black carbon has a harmful local impact. When emitted into the atmosphere, BC are scavenged by clouds, changing rain patterns, thus having an impact on local agriculture. On land, BC reduce the albedo (reflecting power) of snow contributing to ice melting, as presented by figure (6). (UN GRID-Arendal, 2014)

Figure 6: (a) Local Impacts of Black Carbon. (b) Summary of Short Lived Climate Pollutants. Source: UN GRID-Arendal 2014
Figure 6: (a) Local Impacts of Black Carbon. (b) Summary of Short Lived Climate Pollutants. Source: UN GRID-Arendal 2014

A part from pollutant and GHG emissions, OFBC relies on firewood collection and charcoal production that contributes to local deforestation and degrades local biodiversity. Firewood is mainly collected from bushes or dry biomass lying nearby houses. The forest degradation of firewood collection should be considered when coupled with other activities such as path clearing in forest. However, it is very hard in this case to segregate impacts. On the other hand, charcoal is clearly linked with forest degradation since its production involves cutting large trees. Putti et al.(2015) describe how harvesting practices may vary across countries, hence having a differentiated pressure on local biodiversity and land depending on the country context.
Improving the way people cook is at the encounter of health, poverty fighting, gender equality, and environment’s protection, encompassing the triple goal of sustainable development.



Even though cooking technologies evolved through history, government and NGO’s eyes only turned to OFBC challenge in the 70’s, mainly driven by increasing concerns with energy supply and apparent deforestation. Private interest has gained momentum after the implementation of carbon credits for clean cookstove projects, meaning the development of more efficient and less pollutant stoves. Clean cook stove carbon credits became particularly attractive for those willing to invest in projects with broader sustainable effects.
In fact, unlike other carbon credit projects, clean cook stoves are considered as “win-win” since they not only provide emission reduction but also direct and indirect social/health development results. (Freeman and Zerriffi, 2012) Hence, it is now possible to find a broad range of improved and clean cook stoves in the market.
Created in 2010, the Global Alliance for Clean Cook stoves (GACC) is a public-private partnership hosted by the UN Foundation that seeks to mobilize private and public partners in order to build a global industry that would make clean cooking accessible for 100 million household in 2020, and aims towards universal access in 2030.
As mentioned before, improving the way people cook is at the heart of sustainable development and reflects on five over 17 UN SDGs (United Nation Sustainable Development Goals), as presented in figure (7). (Rosenthal et al., 2018)

Figure 7: Sustainable Development Goals (SDGs) of particular relevance to clean cooking programs. Source: Rosenthal et al. (2018)
Figure 7: Sustainable Development Goals (SDGs) of particular relevance to clean cooking programs. Source: Rosenthal et al. (2018)

Over the last 20 years, Asian countries have seen the biggest improvement in clean cooking access. Vietnam, Indonesia and India are the countries that have the biggest increase in percentage of people with access to clean cooking. Since 2000, the three countries experienced a 59, 56 and 27 percentage points increase respectively. After 2010, China has seen its access to clean cooking increase twice faster as in the previous decade. Nevertheless, even with one such improvement, 51% of the most populated country in the world, India, still rely on biomass. (IEA, 2019)
In Africa, Cape Vert holds the biggest improvement with an evolution of 26 percentage points since 2000, but access to clean cook stoves marks a clear disparity between North African countries and Sub-Saharan’s. For most countries of the former region, more than 90% of the population have access to clean cooking whereas for the latter this number falls to 17%. In Republic Democratic of Congo, 96% of the population, 81 million people, still relies on biomass. Improvement in access to clean cooking has not considerably changed after 2010 in Sub-Saharan countries (IEA, 2019).
Moreover, as mentioned in SDG 7 – Affordable and Clean Energy annual reports, access to clean cooking has risen by 3% from 2010 to 2017, reaching 61% of global population. If the annual rate remains at the same level, the world would only see its whole population using clean cooking solution in the beginning of next century, instead of 2030, as target by GACC and SDG 7. (United Nations, 2019)



Challenges to universal implementation of clean cook stoves are several and complex. This article will present some examples that might explain why progress in the field is slow.
One of the most straightforward and claimed challenges relies on insufficient investments. As stated by Dymphna van der Lans, new CEO of GACC, “The level of funding in the sector falls far short of sufficiently matching the global magnitude of this challenge.” Reaching universal adoption of clean cooking by 2030 requires 4 billion USD according to the GACC’s estimation. In 2017, the total investment was 40 million USD. (Bhalla, 2019)
Moving to technical aspects, another main challenge is the lack of common and standardized performance test methodology. As improved and clean cook stoves vary on many aspects such as type of fuel feedstock, design, harm mitigation potential, and material, standardization is key to allow comparison between stove innovations, to ensure more precise performance evaluation and to provide transparent information to consumer. In 2013, International Standard Organization (ISO) created ISO TC/285 Clean Cook Stoves and started standardization process.(Gasiorowski, 2015) Figure (8) draws a summary of the many existing solutions for OFBC in Sub Saharan Africa, based on ISO definitions and evaluation (The World Bank, 2014).

Innovations on cook stoves can be brought into two categories: improved and clean solutions. The former includes cook stoves that improve fuel efficiency without reducing particulate matter emissions and the latter stands for low-particulate-emission technologies. Indeed, improved solution still relies on traditional solid fossil fuel (charcoal and wood) whereas most of clean solution employs modern fuels.

Figure 8: Overview of improved and clean cooking solutions. Source:
Figure 8: Overview of improved and clean cooking solutions. Source:

Performances on efficiency and emission presented in figure (8) refers to tests voluntarily conducted by ISO technical committee. Stoves’ performances are evaluated over five indicators in laboratory conditions: thermal efficiency, fine particulate matter emissions, carbon monoxide emissions, safety, and durability. Grades are given along five ranges, called tiers. Tier 0 being equivalent to open fire simple stoves and 5 being the highest performance. For particulate emission, tier 5 corresponds to limits advocated by World Health Organization’s Guidelines for indoor air quality.(Clean Cooking Alliance, n.d.).
Even with those tests, many uncertainties remain, such as results reproducibility in real conditions. There are many factors hampering the translation of results into real life such as how people tend the fire, the size of meal, type of food being cooked, and moisture level of the fuel..(Putti et al., 2015)
Nevertheless, some conclusions are clear and put in perspective the win-win aspect of improved solutions since they are more energy and emission oriented, and do not change particulate emission thus not contributing to health improvement. On the other hand, clean solutions, which replace solid fuel by modern fuel such as liquefied petroleum gas (LPG), electricity and ethanol present clear health benefits outcomes. (Rosenthal et al., 2018)
Should the GACC move towards clean solution only, then? Michael Shafer, professor emeritus of international political economy at Rutgers University and founder of Warm Heart Worldwide, who has been engaged in the last decade with climate change and sustainable agriculture in northern Thailand, quotes, in a recent article, a focus group participant’s sentence:
“Oh, we know all about bad smoke, but smoke is the only thing that keeps the mosquitos away. We have a choice: die now from disease, or later from smoke. We think later is better.”
This quite strong sentence does not depict situation of all 3 billion people that rely on OFBC. Nevertheless, it stresses the importance of having a systemic view and understanding the particularity of cook stove challenge. As reinforced by a study conducted by The World Bank, in 2014 in Sub Saharan Africa, and illustrated in figure (9), long-term health impact is not one of the main concerns motivating people to switch to cleaner technologies. Another major factor for clean cooking use is accessibility to modern fuel.

Figure 9: Stove design preference for African Consumers: Source": The World Bank 2014
Figure 9: Stove design preference for African Consumers: Source”: The World Bank 2014

By presenting consumer preferences, The World Bank study also opens the debate on the role of consumer behavior change. Putti et al. (2015) describe many examples in which household abandon improved or clean solutions due to either difficult maintenance, or due to fuel price increase. Another important fact is stacking of OFBC and clean solutions, meaning household are using both clean and rudimentary stoves. This phenomenon is very common and appears in several impact assessments. Many factors can explain the persistence of OFBC: alternative when fuel price increases, better fitting with cooking pot, flavors and taste, and necessity of multiple stove for big families.(Putti et al., 2015) Ethan Kay, Director of Emerging Markets at BioLite, also mentions the sacred relation with fire. When talking about new technology adoption, innovation cannot put aside basic needs, beliefs, pleasure, traditions of its final users.
Finally, the way improved and clean cook stoves reach household can be determinant to wide and long-term adoption. Donations sometimes have the side effect of remaining as a short-term solution since it does not directly create a local market that guarantees, for example, spare parts and maintenance for the donated product. Exclusive-giving distribution model can sometimes create culture of dependence and might stripe the opportunity of creating economic activity around a new good, which in the case of poor countries can help household development. (Kay, 2013)



How can an activity like cooking, which is considered for many as pleasure, kill 4,3 million people every year ? Still today close to 40% of global population inhales every day harmful pollutants when burning biomass in open fire stoves to cook inside poor ventilated houses. The harms of this practice goes beyond health and affects poverty fighting, gender equality, and environment protection.
Hence, providing clean cooking is at the heart of sustainable development. Since the 70’s, the world have seen emerge many improved and clean solutions, and the cook stove challenge has earn global coordination and attention after the creation of cook stove carbon credits, GACC, ISO standards, and UN Sustainable Development Goal’s objective of universal access to clean cooking by 2030.
Many challenges hamper the wide and long-term adoption of improved or clean solutions from insufficient investment, technical issues, systemic understanding to consumer behavior aspects. The journey towards universal clean cooking must be done progressively by improving people’s accessibility to alternative fuel, coupling cook stoves projects with other basic health and social needs, and changing user behavior. This will require intermediate improved solutions that need to be effective in providing emission reduction and health outcome but most importantly they need to be adapted to cooking practices and adopted by the users. In that sense, user and usage centric approach is key to create a myriad of solutions that will go beyond stove mechanism innovation and will drive consumer behavior change.
In March 2018, Dymphna van der Lans was appointed CEO of GACC. She rebranded the name of the alliance into Clean Cooking Alliance taking away the focus on the stoves exclusively. In parallel, the Alliance is now holding Investment Forums to raise global attention and investments towards kitchens unchoking process.(Anderson and Milizer, 2019)



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