Thailand’s top 5 greenhouse gas emitters and lowest 5 provinces revealed

In fiscal years 2023–2024, the Thailand Greenhouse Gas Management Organisation (TGO), with support from the Environmental Fund under the Office of Natural Resources and Environmental Policy and Planning, worked with provincial natural resources and environment offices in all 76 provinces to complete greenhouse gas inventories and provincial reduction plans.

The initiative has since been expanded, with 15 more provinces adopting net zero greenhouse gas emission targets in fiscal year 2025. This brings the total number of provinces with net zero goals to 32.

According to the TGO’s consolidated report, five provinces were identified as the highest greenhouse gas emitters in Thailand, while five provinces recorded the lowest levels of emissions.

Thailand’s top 5 greenhouse gas emitting provinces

1. Bangkok
Based on the 2013 baseline year under the provincial greenhouse gas reduction project, Bangkok records more than 40 million tonnes of CO₂ equivalent per year. With a registered population of 5.4 million — and more than 10 million including migrant and working residents — the capital sees the highest levels of emissions. Over 80% come from the energy and transport sectors, driven by intensive production and consumption.

2. Chon Buri
A hub of both industry and tourism, Chon Buri is one of the key provinces in the Eastern Economic Corridor (EEC), home to numerous industrial estates. The province emits over 24 million tonnes of CO₂ equivalent annually.

3. Saraburi
Known as Thailand’s “cement capital”, Saraburi is home to the country’s largest cement manufacturers. The energy-intensive limestone calcination process releases CO₂ directly from both chemical reactions and heavy fossil fuel use. Emissions here exceed 22 million tonnes of CO₂ equivalent per year.

4. Rayong
Thailand’s petrochemical stronghold, Rayong hosts the Map Ta Phut Industrial Estate, which includes oil refineries, gas separation plants, and large-scale chemical factories. The combustion of fuels and chemical processes contribute to more than 18 million tonnes of CO₂ equivalent annually.

5. Samut Prakan
Located on the coast near Bangkok, Samut Prakan is a centre for heavy industry — from steel and electronics to chemicals. Its dense industrial base, energy use in buildings, high population, and intensive transport systems push emissions beyond 14 million tonnes of CO₂ equivalent per year.

Thailand’s five lowest greenhouse gas emitting provinces

1. Phetchaburi
With 64% of its area covered by forest, Phetchaburi plays a vital role in carbon sequestration, particularly through Kaeng Krachan National Park, part of the UNESCO World Heritage-listed “Kaeng Krachan Forest Complex”. Spanning more than 2.4 million rai, this vast forest serves as a “green lung” of the nation, capable of absorbing and storing an estimated 16.4 million tonnes of CO₂ equivalent.

2. Kanchanaburi
Around 67% of Kanchanaburi is forested — some 5.8 million rai — forming part of mainland Southeast Asia’s most intact forest landscape. These western forests are capable of absorbing and storing about 5.86 million tonnes of CO₂ equivalent.

3. Nan
Once notorious for widespread deforestation to make way for maize plantations, Nan has in the past decade shifted towards forest restoration and low-carbon agriculture. Forest cover has now rebounded to around 60% of the province — roughly 4.2 million rai — enabling the absorption and storage of over 4.96 million tonnes of CO₂ equivalent.

4. Mae Hong Son
Thailand’s most forested province, Mae Hong Son is 85% covered by forests — about 7.3 million rai. However, more than 40% of these forests are degraded due to encroachment and recurrent wildfires. With sustained restoration, the province’s forests could absorb and store over 4.92 million tonnes of CO₂ equivalent.

5. Chiang Mai
With about 60% forest cover, Chiang Mai benefits from both natural forests in national parks such as Doi Inthanon and community-managed forests surrounding agricultural areas. Together, they provide the capacity to store more than 3.94 million tonnes of CO₂ equivalent.

Reforestation, renewable energy and urban efficiency needed

However, the TGO also reported that if all of Thailand’s forests were combined, they would be able to absorb and store only 91 million tonnes of CO₂ equivalent. This falls short of the national net zero target of 120 million tonnes of CO₂ equivalent.

This means that cutting greenhouse gas emissions requires strategies tailored to the specific contexts of each province — from renewable energy adoption in industrial hubs, to reforestation and agroforestry in farming areas, and changes in energy consumption patterns in major cities.

If Thailand is to reach net zero within the next 40 years, the provinces with the highest carbon emissions will be the front line of the country’s transition.