20 years on, California’s burning ban comes into force

In 2003 a bill was passed that aimed to eliminate the practice of agricultural burning in California’s San Joaquin Valley. After years of postponements, it has finally come fully into force.

Crop burning is a well known air quality problem in Asia, one we have covered extensively in the past, but the problems in in the US are much less widely reported. 

Farmers turn to burning for a variety if reasons: burning crop residues after harvesting, getting rid of orchard and vineyard prunings, removing weeds, preventing disease and controlling pests.

Back in 2003, the original intention was that the ban be gradually enforced, leading to the burning being fully phased out by 2010. There was however, a provision within the bill that the deadline could be postponed if there was ‘no economically feasible alternative’ to the burning 

Almost inevitably, given the existence of such a provision, applications for the deadline to be postponed were granted year after year. 

In 2021, it was finally agreed that the law would be phased in, with large farms the first to be affected and a near total ban coming into force at the start of 2025. As of this month, the  San Joaquin Valley Air Pollution Control District can only issue burn permits for certain crops and to prevent the spread of disease.

In 2021, these renewed efforts reduced the amount of waste being burned by San Joaquin Valley farmers from around 1 million tons to 480,000 tons. By 2023 this had dropped to 122,000 tons.

The original bill was introduced by then senator, Dean Florez, who joined the California Air Resources Board in 2016.

Speaking to The Fresno Bee, Florez said: ‘My sole goal has always been to eliminate agricultural burning — a vestige of the past that I remember vividly from my childhood in the Central Valley. Growing up, I often wondered why those plumes of fire and smoke were allowed to darken our skies. It symbolized an outdated practice that needed to change, and I’ve carried that vision with me ever since.’

The financial impact of the ban on the farmers themselves has been softened by the provision of $180 million to fund alternatives to traditional burning methods.

One of the technologies many of the farmers and growers have turned to is air curtain burners – a large metal fire box that uses a fan to create a curtain of air that trapping particles to ensuring they are burned completely burned. An air curtain burner can reduce the emission of particulate matter by up to 70%.

Former state Sen. Dean Florez, the San Joaquin Valley Democrat who authored the legislation and until recently served on the Air Resources Board, called the milestone “deeply emotional.” He initially pushed for an immediate burning ban, he said, but has “come to appreciate that true progress often requires compromise and patience.”

‘Farmers needed time to adopt new technologies and practices, and giving them that time has made this transition more sustainable and lasting. What’s most gratifying now is knowing that this moment is definitive—there will be no delays, no loopholes, and no turning back.”