Facing the severe headwinds of climate change, more than 2 billion people in developing countries still cook with traditional fuels that generate black carbon, a powerful greenhouse gas.

While some propose liquified petroleum gas (LPG) to developing urban and rural settings, particularly in Africa, Cornell’s Semida Silveira suggested an alternative eco-friendly cooking fuel: small-scale biogas. She spoke on Dec. 5 to climate change leaders attending the 28th Conference of the Parties (COP28), held in Dubai in the United Arab Emirates.

“About 2.3 billion people still lack clean cooking fuels. This leads to millions of premature deaths every year due to indoor air pollution, who are mainly women and children,” said Silveira, a professor of practice in systems engineering in Cornell Engineering and a member of the Council of Engineers for the Energy Transition (CEET), an independent advisory council to the United Nations’ Secretary-General. “In this modern age, that is incredible. This is a well-known problem. Everyone understands that you must accelerate clean cooking to address climate change and improve the welfare in developing countries.”

Considered a transitional fuel, LPG allows people who cook with carbon-heavy methods like firewood, charcoal and dung – which cause deforestation and greenhouse gas emissions – to switch to a cleaner fuel. The United Arab Emirates are moving ahead with a program to supply LPG to reduce carbon emissions in African countries, Silveira said, but there are other options based on renewable resources.

Small-scale biogas, based on the digestion of organic material such as manure and agriculture residues, can be broadly used on small farms, contributing an affordable and sustainable fuel that is locally available, Silveira said.

Without proper action, she said, about 1.9 billion people will still be using carbon-heavy cooking fuels by 2030 – most of them in sub-Saharan Africa.

The full potential of biogas has not yet been systematically explored for clean cooking purposes, despite it being a proven technology, according to CEET. In 2018, only 6% of the world’s estimated biogas potential was being used.

Silveira suggested opportunities to create synergy between agricultural food systems in the world’s rural areas and concurrently produce biogas to provide cooking fuel. A by-product of the biogas is fertilizer that also has an economic value.

“It’s not easy, but we know what needs to be done” said Silveira, a fellow at the Cornell Atkinson Center for Sustainability. “We’ll have to set up a support system, so that the solution fits the context – for example, the feedstock available – and that no fugitive emissions are created."

Proposals Silveira made at COP28 include creating a biogas ecosystem to scale up biogas solutions for clean cooking and developing guidelines for its implementation. Further, she recommended a communication campaign to mobilize stakeholders and accelerate rural biogas deployment, while developing research on small-scale biogas technology and business models to help build know-how and capacity.

Silveira points out that this is a solution that can create self-reliance and income, while contributing to improve food security. Adding a biogas component in agri-food projects will increase community resilience, she said.

Silveira tried to be hopeful but remained realistic.

“We can only reach the target of universal access to clean cooking by 2030 – which is part of the UN’s sustainable development goals – if we take it more seriously,” she said.