California Governor Jerry Brown has issued a new Executive Order establishing a suite of statewide climate change policies, including one of the most aggressive emission reduction targets ever enacted in North America—reducing GHG emissions 40 percent below 1990 levels by 2030.

California, the world's seventh largest economy, has already established objectives for reducing GHG emissions in both the short term (1990 emission levels by 2020) and the long term (80 percent below 1990 levels by 2050). The new 2030 target is intended to bridge the gap by guiding regulatory and investment decisions in the medium-term.

The 2030 target established in the Executive Order is consistent with the contents of a significant package of climate legislation currently under consideration by the California Legislature. Among other things, the legislation would increase California's Renewable Portfolio Standard to 50 percent  by 2030, require the State's pension funds to divest their holdings from coal companies, and cut the use of petroleum fuels by 50 percent statewide.

The 2030 target is also consistent with the October 2014 climate policy framework adopted by the European Union (EU). The EU framework, like Governor Brown's Executive Order, sets a 2030 GHG emission reduction target of 40 percent below 1990 levels while maintaining a long-term objective of cutting emissions 80 percent below 1990 levels by 2050.

Although the Governor's 2030 emission reduction targets have (justifiably) grabbed the lion's share of headlines, two other aspects of his Executive Order are also worth noting.

First, the Executive Order establishes several new directives addressing climate change adaptation:  It requires the California Natural Resources Agency to prepare an adaptation plan by September 2015 and ensure that the plan is updated at least once every three years; it prioritizes "natural infrastructure solutions" over other adaptation strategies; and it directs all state agencies to "take climate change into account in their planning and investment decisions, and employ full life-cycle cost accounting to evaluate and compare infrastructure investments and alternatives."

Second, the Governor's decision to establish 2030 GHG reduction targets by Executive Order raises important questions about permissible methods of evaluating—and mitigating—climate change under the California Environmental Quality Act (CEQA). CEQA, the state's environmental impact assessment law, generally applies to all discretionary land use planning and development decisions in California—everything from the construction of an office building to the development of utility-scale electric generation projects. The Act requires state and local agencies to identify, evaluate and disclose to the public the environmental consequences of proposed projects. It also mandates that any impacts with the potential to cause "significant" changes in the environment be mitigated or otherwise avoided whenever feasible. CEQA compliance and litigation have long been among the most time- and cost-intensive hurdles facing project developers in the Golden State.

Under existing CEQA law, the "significance" of climate change-related impacts (and therefore the extent of mitigation/avoidance requirements) must be evaluated with reference to (1) any regulations adopted to implement a state or local climate change plan and (2) the extent to which the project will comply with specific, publicly-reviewed mitigation plans. But existing law does not specify the role of an executive order setting general emission reduction targets—as distinguished from a specific, publically-vetted statutory or regulatory provision—in a CEQA analysis. That issue is currently under review by the California Supreme Court. In the meantime, significant uncertainty remains.

It appears likely that Governor Brown's fourth (and final) term in office will continue to be characterized by bold and frequent executive action on climate change. Over the next 6-12 months, however, significant action is likely to take place in other branches of government. Stakeholders are advised to pay particularly close attention to the California Legislature's consideration of significant climate legislation, the Natural Resource Agency's adaptation planning process, and the Supreme Court's resolution of lingering uncertainty over the proper role of executive orders under CEQA.