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How New California Housing Can Slow Global Warming

California’s mild climate and extensive environmental regulations make the state a veritable environmental oasis in America. California is especially “green” in its low level of carbon emissions. The average Californian emits only 9 tons of Carbon Dioxide or its equivalent per year, the second lowest rate in the United States. In fact, California’s Greenhouse Gas (GHG) emission rate is about half the national average, and less than 1/10th the level of the most polluting states.¹

The average Californian emits only 9 tons of Carbon Dioxide or its equivalent per year, the second lowest rate in the United States.

Unfortunately, a handful of California’s supposed environmental laws actually work to drive people and homes out of the state, and into more polluting regions. Many of these laws treat new residents as contributors to California’s emission problem, instead of viewing them as they should, as reducers of global GHGs. Some of these laws may actually exacerbate, instead of ameliorating, global climate change.

One of the best ways for California to mitigate climate change is to make California more welcoming to new residents. Since climate change is a global problem, California’s emissions goals and environmental laws should take into account their own global impact, including how they might attract people to or drive people from California.

California’s emissions goals and environmental laws should take into account their own global impact, including how they might attract people to or drive people from California.

We therefore propose that, at the least, all of California’s environmental laws should evaluate greenhouse gas impacts on a per capita basis, instead of just by total emissions. More optimistically, California should count new residents as positive contributions to reducing global warming, instead of, as today, counting them as additional emitters. In this way, we can help mitigate global climate change, even as we make the great green land of California more welcoming for everyone.

How the California Global Warming Act Can Sabotage its Own Goals

California Assembly Bill 32, the Global Warming Solutions Act of 2006, is rightfully regarded as a landmark environmental reform, and has done much to reduce carbon emissions in the state. The law, along with subsequent amendments, requires the state to return its total Greenhouse Gas (GHG) emissions to 40% below 1990 levels by 2030, and 80% by 2050.²

Shockingly, however, the law’s carbon targets only count total emissions from the state, and make no mention of per capita changes. Thus, ironically, the state’s climate goals can be achieved as much by pushing residents out as by reducing emissions from existing residents. This seemingly minor issue has had grave ramifications.

For one, although California has had notable success reducing GHGs, those gains have been entirely offset by losses in population to other states. Since 1990, California has lost, on net, 3.8 million domestic migrants to other states. These states on average have about double the GHG emissions of California. These lost residents therefore emit about 41 million extra metric tons of CO2 per year.³ This is approximately equal to the entire reduction of annual GHG emissions that has taken place in California since 2006.⁴ Thus for every climate gain we have made inside our state, we have lost as much by driving residents away. Such a loss needs to be acknowledged in California climate policy.

For every climate gain we have made inside our state, we have lost as much by driving residents away.

Many cities and counties, in adopting their own climate plans under AB 32, have used the law to limit housing and population. Marin County’s climate plan includes efforts to “Institute growth boundaries or programs to limit suburban sprawl” and to “Improve the County’s jobs/Housing Balance,” which often means limiting residential development.⁵ Santa Clara County is using greenhouse gas funding from the state to purchase and preserve thousands of acres of agricultural land immediately on the edge of its urban areas, in order to keep away new housing.⁶ Cities like Berkeley have touted their own success in reducing total greenhouse gas emissions, without mentioning that they have done this by restricting population growth.⁷

Even cities that fully mitigate the impact of new development on the climate have seen environmental laws sabotage their efforts. San Diego recently purchased “carbon offsets” for all potential emissions of a new green housing development it permitted.⁸ Yet that project was blocked by a court because it found the carbon offsets focused on “global” impacts of climate, instead of mitigating the emissions locally. Of course, since climate change is a global issue, those impacts should be paramount in any analysis.⁹

Many state-level agencies have counterproductively supported such efforts. The State Attorney General’s offices has celebrated “exemplary and innovative local sustainability and climate policies,” such as “City of San Jose’s Urban Growth Boundary,” “Yolo County’s Jobs/Housing Balance Policy” and so forth.¹⁰ The California Air Resources Board includes in its global warming plan the “conservation of agricultural and other lands” from housing development.¹¹

Lawsuits attacking the supposed negative climate impacts of new housing in California are common.¹² As early as 2007, then Attorney General Jerry Brown sued San Bernardino County over its housing plan, arguing that it allowed too much new development and therefore new emissions. An article at the time noted “the lawsuit is one of at least seven around the state using the global warming threat to challenge building or planning proposals by developers and local governments.”¹³ The fact that the California Supreme Court, in interpreting AB 32, claimed that “Meeting our statewide reduction goals does not preclude all new development,” is not a particularly comforting stance, since it assumes an inherent contradiction between development and meeting climate goals.¹⁴

The argument we’re making here to recognize the climate benefits of new housing is not an argument to relax environmental regulations. Although there is reasonable debate about how environmental regulations could push some industries or jobs to low-cost or low-regulation areas, there is no such a debate on housing.¹⁵ The relationship between housing construction and population, especially in a growing area like California, is almost one-to-one.¹⁶ Thus for every new housing unit built in the state, there will almost certainly be one new household, of slightly over 2 people on average, emitting lower total GHGs. Given that the value of a new home in California is significantly greater than the cost of construction, environmental building codes are not the major deterrent to new homes. Environmental laws and urban zoning that completely block such development are far more important.¹⁷ As long as the housing is actually allowed, significant environmental regulations will not deter it. Yet right now, all California housing faces the unnecessary burden of proving that it will have little or no local climate impact, when its real impact is almost always towards reducing global emissions.

How “CEQA” Can Exacerbate Environmental Harms

One of the most frequent barriers to new housing in California is the California Environmental Quality Act (CEQA) and its requirement of extensive “CEQA reports” on new development. Unfortunately, the law’s anti-housing tendency is exacerbated by a false conception of the GHG impacts of new development. A 2007 law, SB 743, required all CEQA reports to show that a new development mitigates its potential GHG emissions.¹⁸ CEQA should instead acknowledge that new housing in California reduces global emissions and therefore global warming.

A 2007 law, SB 743, required all CEQA reports to show that a new development mitigates its potential GHG emissions. CEQA should instead acknowledge that new housing in California reduces global emissions.

Opponents of development have used CEQA report lawsuits to block many types of green infrastructure, such as a parking company that sued a proposed rail line to the Los Angeles airport. In a recent egregious case, the California Supreme Court demanded a new CEQA report on a project which had been in the pipeline for 25 years, and whose CEQA report had been in process for five of those years, and which overall promised to be a “net zero” greenhouse gas project. The California Supreme Court, however, said that the current CEQA report did not show that reduction in greenhouse gases was “sufficient” to meet the state’s greenhouse gas goals, even though it was a clear global gain relative to a no-development baseline.¹⁹

The baseline assumption, in fact, for all CEQA reports is that new development is an environmental hazard that must be deterred or mitigated. CEQA reports today are required to analyze the “growth-inducing impacts” of new development as a potential threat.²⁰ To that end, the Bay Area Air Quality Management District, which implements CEQA climate change regulations, advocates blanket reductions in “land-use driven” emissions, meaning more development.²¹

Luckily, some state officers have taken steps to evaluate CEQA greenhouse gases effects by per capita, instead of total, emissions. Most specifically, the California Office of Planning and Research has declared the “significant threshold” (after which all new projects need to account for and mitigate climatic impacts), for new housing and jobs is “per capita or per employee VMT [Vehicle Miles Traveled] that is 15% below that of existing development.”²²

Yet this 15% reduction in VMT relative to the California norm is still an inappropriate metric for the “negative” impact of a new housing development. For one, VMT is a very poor measure of climatic impact. Today, California’s low carbon emissions have little to do with driving behavior, and everything to do with its mild climate and carbon-free energies, including for existing electric and hybrid cars. Californians drive only about 10% fewer miles per year than average Americans, despite emitting only half as much carbon.²³ The Bay Area ranks about in the middle of large urban areas nationally in terms of VMT per capita per day, at about 25, and LA is about the same, even though these areas have very low per capita GHG emissions.²⁴ Reducing driving in these areas by stifling new development will not mitigate climate change.

Controls on supposed “high VMT” projects often do not even restrict VMT on a per capita basis, let alone on a total basis. Although planners hope that any denial of “sprawling” development will prevent driving, often the opposite is the case. When one region prevents new projects, another region often attracts the displaced residents. This is happening today in the Bay Area and Central Valley cities. Due partially to decades of supposed anti-sprawl housing policy, San Francisco is second in the nation in “supercommuters,” or people who spend over 3 hours a day getting to and from work. They total over 100,000 people, or about 5% of the working population. San Francisco’s supercommuters have increased by over 110% in the past decade, the fastest increase in the nation.²⁵ By fighting “sprawling” development, planners often just push workers into even more distant, and sprawling, areas. Despite attempted controls on land use, there is no ability to control where people live and where they work.

In evaluating CEQA reports, the California Supreme Court has supported the per capita VMT and other limits instituted by state regulators. They have noted that “CEQA is not intended as a population control measure. Of note, the future residents and occupants of development enabled by Project approval would exist and live somewhere else if this Project is not approved. Whether ‘here or there,’ GHG emissions associated with such population growth will occur.”²⁶ In reality, the general assumption of the negative climatic impacts of development, and the low VMT “significant threshold” for CEQA reports, effectively functions like a population control measure, preventing much new development that would reduce global GHG emissions.

The general assumption of the negative climatic impacts of development, and the low VMT “significant threshold” for CEQA reports, effectively functions like a population control measure, preventing much new development that would reduce global GHG emissions.

The Environmental Benefits of “Greenfield” Development

As the previous discussion of Vehicle Miles Traveled indicates, much of the debate about new development in California is also a debate about “sprawl,” a term that is often vaguely defined. Yet California needs to understand that allowing new development, even development occasionally derided as “sprawl,” and even development on its “greenfields,” is still a win for the global climate relative to the alternative of allowing no development at all.

For one, dense development does not have significant effects on driving behavior. A recent metasurvey showed that increasing existing densities by 40% would only reduce per capita driving by 5%. Such an increase would be at the extreme end of density increases in U.S. history, and would be unlikely to occur.²⁷ In fact, the Bay Area is one of the few metropolitan regions to “densify” in the past 30 years, and yet it has seen no decrease total VMT, and an 11% decline in transit ridership.²⁸ Current estimates are that even if 3/4s of new housing were built at twice the density of current development, an unobtainable goal, this would reduce CO2 emissions by personal transportation, which is itself only about 25% of all emissions, by less than 10% by 2050.²⁹

On the whole, even if dense new development significantly lowered automobile VMT and increased transit usage, there would be little to no climate impact. Back in 1970, cars used about twice as much energy per passenger mile traveled as buses, about 4,900 British Thermal Units, to 2,500 units. Those measures are now reversed, with cars using about 2,900 BTU, and buses about 4,100 BTU per passenger mile. While the energy efficiency of cars is improving over 1% per year, buses have actually been getting about 1% dirtier per year. Commuter rail is about 2,700 BTUs per passenger mile, and rail transit in general is close behind. Thus today, rail transit and autos have the same total energy use, but the trains are getting dirtier while cars have continued to get cleaner.³⁰ California’s mandates on electric vehicles will make cars an unquestionably cleaner source of transportation within the next few years.

The likelihood of much denser development is further limited by the fact that California cities are already the densest in the United States. Of the 10 most densely populated urban areas, 7 are in California, with Los Angeles, counter to its reputation, being the densest overall metro, and San Francisco being third. At around 4,300 people per square mile, coastal California cities are already more than twice as dense as the rest of the United States.³¹

Since California cities are already very dense, have little “infill” space left, and are reluctant to displace current residents, the only hope to bring new residents to the state is building in its current “greenfields.” Contrary to myth, this does not mean bulldozing pristine virgin paradises. Today, 40% of the 9 county Bay Area region is taken up by grazing cows, whose belching methane gas are a genuine global warming concern. Another 20% is taken up by purely private agricultural land. Since today agriculture uses 80% of the water in the state, it in fact presents a significant environmental issue.³² If this incredibly valuable land was instead taken up with all new housing, it would be an unalloyed good for the globe, bringing more people from cold and dirty regions to California’s friendly and mild clime.

Today, 40% of the 9 county Bay Area region is taken up by grazing cows, whose belching methane gases are a genuine global warming concern.

Pushing people into denser developments also does not seem to have a positive impact on GHG emissions made by the home itself. Multi-family homes do not, on average, use less energy than single-family homes. Multi-family homes used on average 78,000 BTUs per square foot of heated space per year, while single-family homes use only 55,000 BTUs. This is partially because multi-family homes use more energy heating and cooling “common areas,” like stairwells and lobbies. At the same time, construction of large-multifamily buildings often involves concrete rather than timber, and concrete has significantly higher GHG emissions, from twice to seven times as high, per square foot of new construction as timber.³³ Therefore, California’s law should look at the overall environmental impacts of new building, and not merely whether they are single or multi-family. The current green building codes do a much better job of controlling emissions than land-use controls on different types of development.

Some might argue that restricting sprawling development would force more people into the dense areas, which might have some minor climate benefits. Yet forty years of California history shows that most developments denied around the region do not suddenly appear inside the central city. We can and should allow as much dense development as we can inside California’s cities, but that is not mutually exclusive to the goal of allowing new development on the outskirts of existing cities. California must learn to embrace all sorts of development if it is going to help fight climate change.

Some Prospective Reforms, to Improve Housing and the Environment

Some simple environmental reforms could allow more housing development in California even as they help ameliorate global climate change.

First, and at the least, California should modify AB 32 and its climate targets so that they aim at “per capita” reductions in emissions, and not total reductions. This would encourage more GHG efficiency, instead of merely meeting the target by driving people away, and help keep more people in our low-GHG state.

It would be even more effective if California could modify AB 32 to take into account the net benefits from encouraging more migration into the state. California should recognize that a person who halves their climate emissions by moving from Texas to the Bay Area is part of the necessary goal of reducing global climate changes. With this reform, we can more easily achieve our climate goals by attracting more people from the United States, even with the same or greater reductions in total global emissions.

California could modify AB 32 to take into account the net benefits from encouraging more migration into the state.

CEQA should also be modified to take into account the climatic benefits of development. Instead of limiting new development unless it encourages significantly less driving than other housing, it should at least make the CEQA “significant threshold” for a new development the same as other states’ VMTs, instead of lower than the already lower VMT in California. Better, the opponents of any particular CEQA report should have to show that the total lifetime GHG effects of new housing development are less than an equivalent development in other states.

Ideally, since California housing today is a clear victory for the climate, all new housing should be exempted from CEQA, which can occasionally take up to thousands upon thousands of pages of wasted paper per project. Under this proposal, all new housing developments would still be forced to abide by other green building codes and environmental regulations on habitat preservation and so forth, but they would actually be allowed to be constructed if they met those requirements.

More generally, California cities and counties should open themselves to more development. Instead of using climate as an excuse to drive people away, advocates should use climate arguments to bring more residents into these cities, both in infill areas inside the cities and even in “greenfield” areas on its immediate fringes. Thus every city climate plan should include a description of what it can do to attract more residents, instead of the opposite.

For decades, California has been a leader in environmental laws but a laggard in welcoming new residents. It is time to stop using a false and parochial sense of environmental impact in order to limit growth. The climate change problems we face are global, and California’s environmental laws, and housing policy, must take this into account.

[1] United States, Energy Information Administration, “Energy Related Carbon Dioxide Emissions by State, 2005–2016,” February 27, 2019, Table 6,;“U.S. States by Carbon-Dioxide Emissions Per Capita,” World Atlas, 2014
[2] Public Policy Institute of California, “AB 32,”
[3] David Friedman & Jennifer Hernandez, “California Environmental Quality Act, Greenhouse Gas Regulation, and Climate Change,” (Chapman University Center for Demographics and Policy, 2015), 48. California as a whole has grown in population, due to natural increase and international immigration, but at only about the national average rate. Net domestic migration is the best measure of California’s ability to attract or repel other residents from the United States.
[4] California Air Resources Board, California Greenhouse Gas Emissions for 2000 to 2015, 2017 ed., p. 1–2.
[5]  Marin County, “Marin County Climate Action Plan,” July 2015,
[6] Johnny Magdaleno, “In Wealthy Silicon Valley, a $500 Million Plan to Save Threatened Farmland,” Reuters, August 8, 2019,
[7] Dee Williams-Ridley, City Manager, to Timothy Burroughs, Director, Planning and Development Department, “Climate Plan Action Update,” December 6, 2018,
[8] Alison St John, “Sierra Club Sues San Diego County Over Carbon Offsets For New Developments,” KPBS, September 6, 2018, One could argue that such a development is itself a carbon offset that attracts other people to California.
[9] Frank Gormlie, “Judge Rules Against San Diego County’s Plan on Greenhouse Gas Emissions- Brings Major Residential Developments to a Halt,”, January 7, 2019,
[10] California Attorney General, “Sustainability and General Plans: Examples of Policies to Address Climate Change,” January 22, 2010,
[11] California Air Resources Board, “California’s 2017 Climate Change Scoping Plan,”November 2017, Despite overall AB 32 goals, many places, like Caltrans, OPR, and other agencies have made efforts to evaluate emissions on a per capita basis, or to at least include expected population growth in their calculations. Caltrans, “California’s Transportation Plan 2040,” June 2016,
[12] See, e.g., Kevin Fixler, “Sonoma County Housing, Hotel Project Sued Over Greenhouse Gas Emissions Concerns,” North Bay Business Journal, August 6, 2019,; ust Elijah CHiland, “Envnronmental Groups Sue Over 12,000 Acre Centennial Devleopment in Northern LA County,” LA Curbed, May 28, 2019,
[13] Mark Martin, “Sprawl Clashes with Warming in California, SFGATE, May 27, 2007,
[14] Center for Biological Diversity v. The Newhall Land and Farming Company, 62 Cal.4th No. S217763, Supreme Court of California, November 30, 2015,
[15] Wayne B. Gray and Ronald J. Shadbegian, “When Do Firms Shift Production Across States to Avoid Environmental Regulation?” National Center for Environmental Economics Working Papers Series, #02–02, January 2002, reasonably Sarah Stafford, “The Impact of Environmental Regulations on the Location of Firms in the Hazardous Waste Managmeent Industry,” Land Economics 76, no. 4 (Nov., 2000): 569–589.
[16] For decades, in fact, population has been reasonably estimated from the number of housing units in an area SK Smith and M. Mandell, “A Comparisons of Population Estimation Methods,” Journal of American Statistical Association 79 (1984): 282–9.
[17] Morris A. Davis and Jonathan Heathcote, “The Price and Quantity of Residential Land in the United States,” Journal of Monetary Economics 54, no. 8 (Nov. 2007): 2596–2620,
[18]  “California Senate Bill 743: An evolutionary change to transportation impact analysis,” Fehr & Peers, California’s SB 375, adopted back in 2008, which covers regional transportation planning agencies, allows them to use per capita VMT as a metric for success, but those transportation agencies have limited authority. Louis Bedsworth, et. al., Driving Change: Reducing Vehicle Miles Traveled in California,” Public Policy Institute of California Papers, 2011,; Senate Bill №375, Chapter 728, September 30, 2008,
[19]  Kerry Jackson, “Welcome to California,” City Journal, July 8, 2019,; Center for Biological Diversity v. The Newhall Land and Farming Company, 62 Cal.4th No. S217763, Supreme Court of California, November 30, 2015,
[20] State of California, Title 14, Division 6, Chapter 3 “Guidelines for the Implementation of the California Environmental Quality Act,”; Port of Los Angeles, Environmental Impact Report, Chapter 7, Growth Inducing Impacts, January 2012, Although the state denies that such impacts should be regarded as either positive or negative, it’s guidelines show concern with any construction that could “significantly affect the environment.” We do not want to argue that there are no environmental concerns with development that need to be addressed, such as species habitat destruction or water usage. We only mean to argue that those other environmental concerns should be weighed against the possible climate change benefits of new housing.
[21] Bay Area Air Quality Management District, “California Environmental Quality Act Guidelines Update: Proposed Thresholds of Significance,” November 2, 2009, The plan allows individual projects to measure their “per capita” reductions, but the overall evaluation of projects and reductions required is not per capita. For impacts see Alexander G. Crockett, “Addressing the Significance of Greenhouse Gas Emissions Under CEQA: California’s Search for Regulatory Certainty in an Uncertain World,” Golden Gate University Environmental Law Journal 4, no. 2 (Jan. 2011): 203–250.
[22] Governor’s Office of Planning and Research, “Technical Advisory on Evaluating Transportation Impacts in CEQA,” November 2017,
[23] Jeff Davis, “Trends in Per Capita VMT,” Eno Transportation Weekly, June 7, 2019,; Office of Highway Poliyc Information, Federal Highway Administration, “Selected Measurs for Identifying Peer States,” Table PS-1, October, 2017,
[25] Sydney Bennet, “Rise of the Super Commuters,” Apartment List: Rentonomics, April 24, 2018,; Michelle Robertson, “Stunning Increase in Bay Area ‘super commuters’ in the last decade amid housing crisis,” SFGATE, April 27, 2018,
[26] Center for Biological Diversity v. The Newhall Land and Farming Company, 62 Cal.4th No. S217763, Supreme Court of California, November 30, 2015,
[27] David Brownstone, “Key Relationships Between the Built Environmental and VMT,” Special Report 298, Transportation Research Board, 2008,; Tim De Chant, “More Density Equals Less Driving: Just an Urban Legend?” Grist, July 14, 2011,
[28] Metropolitan Transportation Commission, “Transit Ridership,” MTO Vital Signs,
[29] Phil McKenna, “Forget Curbing Suburban Sprawl: Building Denser Cities Would do Little to Reduce C02 emissions, a new National Academy of Science Report Concludes,” MIT Technology Review, September 3, 2009,
[30] Stacy C. Davis and Robert G. Boundy, Transportation Energy Data Book, Ed. 37 (Washington DC: U.S. Department of Energy, 2019), Table 2.14, p. 2–19,, The most recent report no longer includes the impact of the original production and transmission of electric energy for rail transit, so this calculation used the 2016 counts. Stacy C. Davis, Susan E. Williams, and Robert G. Boundy, Transportation Energy Data Book, Ed. 35 (Washington DC: U.S. Department of Energy, 2016), Table 2.16, 2–20,21., California has been making notable efforts to make its bus fleet electric, so its CO2 emissions are probably proportionally lower than its BTUs, but California’s car fleet is also quickly becoming more electric. In any case, the “load factor” of transit has continued to decrease in almost all areas of the U.S., and shows little sign of abating.
[31] Wendell Cox, “California’s Dense Suburbs and Urbanization,”, March 15, 2018,
[32] American Farmland Trust, et. al., “Sustaining Our Agricultural Bounty: An Assessment of the Current State of Farming and Ranching in the San Francisco Bay Area,” March 2011,
[33]  U.S. Department of Energy, Buildings Energy Data Book, 2011 (Washington DC: US DOE, 2012), I-32