Climate Justice and California’s Methane Superemitters: Environmental Equity Assessment of Community Proximity and Exposure Intensity

Abstract

Methane superemitters emit non-methane copollutants that are harmful to human health. Yet, no prior studies have assessed disparities in exposure to methane superemitters with respect to race/ethnicity, socioeconomic status, and civic engagement. To do so, we obtained the location, category (e.g., landfill, refinery), and emission rate of California methane superemitters from Next Generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) flights conducted between 2016 and 2018. We identified block groups within 2 km of superemitters (exposed) and 5−10 km away (unexposed) using dasymetric mapping and assigned level of exposure among block groups within 2 km (measured via number of superemitter categories and total methane emissions). Analyses included 483 superemitters. The majority were dairy/manure (n = 213) and oil/gas production sites (n = 127). Results from fully adjusted logistic mixed models indicate environmental injustice in methane superemitter locations. For example, for every 10% increase in non-Hispanic Black residents, the odds of exposure increased by 10% (95% confidence interval (CI): 1.04, 1.17). We observed similar disparities for Hispanics and Native Americans but not with indicators of socioeconomic status. Among block groups located within 2 km, increasing proportions of non-White populations and lower voter turnout were associated with higher superemitter emission intensity. Previously unrecognized racial/ethnic disparities in exposure to California methane superemitters should be considered in policies to tackle methane emissions.

Air pollution and health impacts of oil & gas production in the United States

“…Methane emissions from O&G are a major climate policy concern [1,24], and many policies that affect the emissions of methane from O&G production may also affect emissions of air pollutants and consequent health impacts [22,25]. Therefore, understanding the health impacts of air pollution from O&G production is important from a climate 'co-benefits' perspective, a public health perspective, and an environmental justice perspective [26][27][28][29][30]. Observational studies indicate that populations living in proximity to or downwind of oil and gas activity have higher rates of poor birth outcomes [31], asthma exacerbations [32], emergency room visits [33], hospitalizations [34], cardiovascular disease [35] and other adverse health outcomes [36].…”

Temporal Trends of Racial and Socioeconomic Disparities in Population Exposures to Upstream Oil and Gas Development in California

“…Casey et al. ( 2021 ) found that California residents of color and those with less political engagement are more likely to live near wells with higher methane emissions. Similar patterns have been observed in other states.…”

Toxic Tides and Environmental Injustice: Social Vulnerability to Sea Level Rise and Flooding of Hazardous Sites in Coastal California

“…This approach helps to ensure our analysis focuses on the places where people live and reduces measurement error in the estimation of distance between residences and hazardous sites at risk. Our method was utilized and is detailed further elsewhere. ,, Briefly, we created a high-resolution (i.e., sub-block) map of populations residing near potentially hazardous facilities of resolution that was comparable to the facility boundaries and digital elevation data we used; this entailed developing a statewide, 100 m-resolution “target” population grid within census blocks for which population counts were observed in the 2010 census, using two ancillary data sources: (1) a statewide database of more than 12 million individual tax parcel boundaries from DMP LightBox and (2) spatial building footprint data for nearly 11 million buildings in California. The latter is part of a nationwide layer developed by Microsoft using satellite imagery and machine learning classification techniques…”

“…Flood-induced contaminant releases are more likely to impact low-income households and people of color because they are more likely to live near industrial and hazardous waste facilities. − Socially disadvantaged communities also have fewer resources to anticipate, mitigate, cope with, or recover from the effects of flooding. Prior research shows people of color and the poor are less likely than others to own a car enabling evacuation, more likely to suffer injury or die during the aftermath of an extreme flood event, and less likely to return and rebuild afterward. − In the case of Hurricane Harvey, pollutant releases from petrochemical facilities associated with flooding disproportionately impacted neighborhoods with higher proportions of low income and Hispanic residents …”