As the severity of climate change increases, farmers have emerged as the most vulnerable victims due to the unusual decline in crop yields.
Experts are urging the government to come up with plans to mitigate the problem, with food security among their greatest concerns.
Witsanu Attavanich, an economics lecturer at Kasetsart University, is leading a research project entitled "Effects of Climate Change on Thailand's Agriculture."
In the project, which kicked off in 2017, the country's cash crops are studied based on two farming scenarios: temperatures increasing by 2-3C, and rising by 4.5C, by the year 2100.
The study has found that within the next 70 years, Thailand's overall rice production will decline by 10.18% and 13.33% respectively.
Critical drops are to be seen in non-irrigation zones, which account for three-quarters of the land where rice plantations are located, of 31.9% and 42.2%.
Harvests per rai for sugar cane, cassava and durian are also expected to decrease in the 70 years, with sugar cane to drop as much as 25%-35%.
The study spans 30 years and is to wrap up by 2055.
"Most farmers in Thailand cannot adapt to climate change and lack access to smart farming technology, which makes them the most fragile group in a crisis," Mr Witsanu said.
"The authorities have been presenting climate change adaptation plans for so long, but the problem is the farmers cannot turn the plans into action," he said.
Many farmers are senior citizens who find it hard to adopt digitally innovated processes and new technologies, he said. Also, most of the 12.6 million farmers in Thailand live in remote areas with limited or no access to digital technology infrastructure.
"Unless there are good measures for adaptation and mitigation, the country will face poor food security in the future," he said.
Only 15% of farmers in the northeastern region have access to irrigation.
He suggested the government invest more in small-scale water reserves in remote areas such as wells and underground water sources.
Also, the state-owned agency should work closely with local organisations to train farmers on how to adapt to climate change. "The country plans to subsidise farmers who lose produce from natural disasters.
"Such subsidies, however, should be granted with conditions to help the agriculture sector in the long run.
"Money should be spent on research and improving infrastructure, not just on subsidies, which don't create sustainable benefits," he added.
Witsanu: Farms lack 'smart' tech
Withoon Liemchamroon, director of the BioThai Foundation, said single-crop plantation is a major cause of greenhouse gas emissions and destroys food security.
"We must go back to agroecology by reducing use of hazardous chemicals and fertilisers," he said.
Mr Withoon said the government should create a legal tool to demolish food monopoly businesses, which spread the single-crop plantation concept and discourage food diversity and security.
"The government should support more options for food distribution to open more spaces for food competition," he said.
He also said the problem of declining food security might lead the government to throw its support behind GM crops, which is not ideal for enhancing food security.
Pirun Saiyasitpanich, chief of the Department of Climate Change and Environment, said the average highest temperature has increased by 1.1C and is expected to increase by 2-3C by the end of this century.
Mr Pirun said the department will work with other stakeholders on adaptation plans against climate change. The issue of food security is included.
Withoon: Single crops a problem