Why food waste composting may fail

Imagine an enormous pile of leftover rice, vegetable scraps, or fruit peels dumped to landfill, slowly rotting and filling nearby communities with an unpleasant smell.

- Parichat Suknark

A photo shows leftover food. Many households now turn leftover food into fertilisers. PHOTO COURTESY OF CENT

(PHOTO COURTESY OF CENT)

But the smell is not the only problem.When food scraps and garden waste are buried, they decompose. The process of how leftover food — often called “food waste” — decomposes is chemical. Without oxygen, the process releases methane — a greenhouse gas far more potent than carbon dioxide.

In terms of carbon emission reduction, the waste sector plays an important role in the country’s path towards Net Zero. Under Thailand’s NDC 3.0 climate pledge, the country aims to reach net zero emissions by 2050. The emission reduction potential of the waste sector is estimated at around 4.9% of total reductions by 2035.

Even so, the waste sector receives just around 1% of Thailand’s climate mitigation investment, according to estimates in our study, “Thailand Climate Finance Landscape 2025” Regrettably, the government should invest more because money put into this sector yields a higher return. Waste composting is known as a cheaper form of emission reduction. It offers relatively low abatement costs per tonne of emissions reduced.

Indeed, policymakers have high confidence in Thailand Voluntary Emission Reduction Program (T-VER) projects, particularly organic waste composting and decentralised processing schemes.

These projects are expected to reduce emissions by up to 0.42 million tonnes of carbon dioxide equivalent (MtCOeq) per year — close to the estimated mitigation potential of around 0.5 MtCO2eq by 2035 under NDC 3.0. On paper, this suggests that composting targets could be achieved within a single year. The reality is different.