Not many of us experience having to light a hearth in the wee hours of the morning to boil a pot of water or keep the embers alive to continue the days’ cooking. But prior to the 1980s, almost all houses in Sri Lanka had an outdoor kitchen which had a covering to protect it from the rain, so the cooking could continue even during the rainy season.
Cooking was a task of its own in any household with sourcing firewood to light the hearth and mastering the skill of lighting the hearth being left to the housewives.
Exposure to outdoor air pollution by cooking this way is found to cause premature deaths of an estimated 4.3 million people, annually, from lung cancer, cardiovascular disease, pneumonia, chronic obstructive pulmonary disease (COPD), as well as ill-health and the loss of productivity among millions more.
With the introduction of liquefied petroleum gas (LPG) for domestic usage, gradually, many households are able to do away with the outdoor kitchen and move the kitchen indoors, saving time in having to fetch wood or having to struggle lighting the hearth.
From a global perspective, LPG currently provides about 3% of all energy consumed globally and is used by over a billion people on all continents. Approximately 45% of the total global consumption of LPG is used for domestic applications, primarily cooking.
Reducing air pollutants
Dial back 30 years, and the amount of time and energy spent by a person who spends a lot of time in the kitchen would be doubled. Such persons would have to tend to the hearth and watch over the pot of rice that was to be boiled. The fire needs to be controlled as too much fire at the wrong time could burn the rice. With an LPG cooker, one can regulate the strength of the fire from low to mid to high, at any point, with a turn of a knob.
The carbon emission would be higher from a wood-fired stove in comparison to an LPG cooker. Which means the amount of air pollutants that is generated with a simple task like cooking can now be greatly reduced.
Fine particulate matter is associated with a broad spectrum of acute and chronic illnesses, such as lung cancer, COPD, and cardiovascular disease. Worldwide, it is estimated to cause about 16% of lung cancer deaths, 11% of COPD deaths, and more than 20% of ischemic heart disease and stroke.
LPG emits virtually no black carbon and if spilled, will not pollute the ground. In the event of a leak, LPG does not contaminate the soil or aquifers. This is especially important when operating in environmentally sensitive areas such as farms, nature reserves, or on water.
In a study carried out by the World Health Organisation (WHO) in 2006, in a scenario in which 50% of the people using solid fuels worldwide switch to using LPG, the total economic benefits amount to roughly $ 90 billion per year, compared with net intervention costs of only $ 13 billion (i.e. a benefit-cost ratio of 6.9), with time-saving accounting for half of the gross economic benefits and health-related productivity gains for most of the rest.
In a pro-poor scenario, in which priority is given to households using the most polluting fuels, the economic benefits are even higher, at $ 102 billion, with a net intervention cost of just $ 15 billion.
It also entails a waste of productive time and energy, as traditional fuels usually have to be collected and transported to the home, and cooking with biomass is slow. The local and global environment may also be degraded, as the demand for biomass encourages deforestation; the use of animal waste degrades soil quality and, to the extent that it is used unsustainably, burning biomass contributes to global warming and local and regional air pollution.
As a low-carbon, low-polluting fuel, LPG is recognised by governments around the world for the contribution it can make towards improved indoor and outdoor air quality and reduced greenhouse gas emissions.
In many applications and regions, LPG is among the most attractive energy options for the minimisation of greenhouse gas (GHG) emissions.
LPG’s contribution to mitigating emission is twofold:
1.Reduced CO2 emissions
Whether used for cooking, transport, heating, or industrial applications, LPG is a clean burning fuel that will reduce carbon dioxide (CO2) emissions compared to biomass, fuel oil, and, in many countries, electricity.
LPG is also among the lowest carbon-emitting fuel sources for cooking in many regions of the world. In India, for example, LPG emits 60% fewer GHG than electric coil cooktops, 50% fewer emissions than some biomass stoves, and 19% fewer GHGs than kerosene stoves.
When used as a transport fuel, LPG emits less CO2 than other hydrocarbon fuels when in combustion. Driving on autogas (common name for LPG) leads to a reduction of 10-12% in CO2 emissions, in comparison to a petrol-powered car with an identical engine.
Regardless of the application, switching to LPG will help reduce CO2 emissions.
2.LPG and black carbon
Black carbon or BC are microscopic airborne particles commonly known as soot, which some experts rank as the second-biggest contributor to climate change after CO2.
BC is emitted from incomplete combustion in diesel engines, industrial smokestacks, residential cooking fires, and heating stoves, among other things. But because BC stays in the atmosphere for only days or weeks, moving quickly to expand access to already existing clean technology can be an effective rapid response to reduce BC emissions.
BC warms the planet by absorbing heat in the atmosphere and reduces albedo – the ability to reflect sunlight – when deposited on snow and ice. BC stays in the atmosphere for only several days to weeks, whereas CO2 has an atmospheric lifetime of more than 100 years.
Thus, reducing BC will deliver immediate cooling more quickly than reductions in CO2 and will buy time to keep temperature increases below a critical value, while long-term strategies to reduce CO2 emissions are implemented.
LPG emits virtually no particulates and switching to LPG can thus have an immediate impact on global warming.
Benefits of LPG usage
- 3.7 million deaths in the world are attributable to ambient air pollution
- 1,600 cities worldwide are reporting air pollution levels
- 96% autogas-fuelled cars generate 96% less NOx than diesel and 68% less than petrol
- Autogas emits 120 times less small particle emissions than diesel vehicles
- The carbon footprint of LPG is 50% lower than coal
- Driving on autogas leads to a reduction of 10-12% in CO2 emissions, as compared to petrol