California has long held a position of national leadership in promoting environmental policies. The state has aggressive green building regulations, the most powerful state air quality agency in the nation – CARB, the California Air Resources Board- and crafted the famous “California Environmental Quality Act,” a 1970 law which established some of the earliest and strictest standards in the country for environmental review of proposed projects. California’s legislature has invested in “green” electricity, banning new coal and nuclear plants while subsidizing wind and solar power.

California’s emphasis on environmental protectionism isn’t simply a practical matter, but benefits from a sort of popular Zeitgeist as well. Many Californians pride themselves on their state’s proactive stance in its crafting of environmental policies - a 2010 report by the Public Policy Institute of California, a nonprofit research and polling organization, showed a majority of Californians support restricting offshore drilling, expanding renewable energy production, tougher vehicle emissions standards and the state’s efforts to curb global warming. Politicians often brag about their commitment to the environment. In 2010, the campaign for current governor Jerry Brown boasted his clean energy plan would add 500,000 jobs to the state’s economy over the next 10 years.

But California’s image as a “green” policy trendsetter belies the reality that its system of environmental laws and regulations imposes costs on businesses disproportionate to those of many other states. In addition to claims that it is plagued by conflicting and duplicative regulations, it has at times also pursued costly policies based on what was later revealed to be flawed or incomplete science.

In many ways, the case of California farmers and agricultural businesses is a prime example. After decades of comparably light environmental regulation -at least in relation to other state industries- farmers in recent years have faced a sudden spate of new laws and rules targeting their impact on the state’s environment, which is beset by some of the worst air quality in the nation, as well as groundwater in many areas that has been contaminated by chemicals linked to agriculture.

But the policies implemented to solve these problems have given rise to numerous controversies in recent years. It’s not unusual for one agency’s regulations to seek to address one type of pollution while exacerbating problems involving a different one. Researchers at some of the state’s top agricultural research schools have at times criticized various farming regulations for relying on flawed studies or being unrealistically strict. And farmers complain that many new rules overestimate the impact of agricultural practices on the environment, and prescribe burdensome and sometimes ineffective remedies.

A relatively recent high-profile case where flawed data was used to craft regulations impacting businesses including agriculture involved the California Air Resources Board, which is responsible for creating policies to reduce air pollution statewide. The board had to significantly amend new diesel regulations for construction equipment and trucks -among the strictest in the nation- in 2010, when research by the agency was found to have substantially overstated diesel emissions by those types of vehicles in California.