Climate

Like many cities around the world, Los Angeles is already experiencing the impacts of climate change first hand. In order to align with state and regional climate goals, the city of Los Angeles is taking steps to help residents adapt and become more resilient in the face of these changes, while simultaneously mitigating greenhouse gas (GHG) emissions through targeted policies, such as building decarbonization.

Los Angeles County is a biodiversity hotspot that harbors over 4,000 species of plants and animals. The most populous county in the nation, L.A. County offers a unique environment where more than 10 million people coexist with wildlife. The biodiversity of L.A. County provides many benefits to people, including air and water purification, food security and mental/physical well-being. But land development and climate change threaten the county’s species, their habitats, and the region's ecosystem. With 1 million animal and plant species globally facing extinction due to human activity, efforts to better understand the factors that shape biodiversity in Los Angeles could help shape global conservation efforts. 

California is becoming hotter and drier because of climate change. From 2011 to 2015, the state experienced an extreme drought characterized by unprecedented high temperatures and low precipitation. The drought resulted in record-breaking dry soils, significant agricultural damage, and rapid depletion of groundwater resources. Despite ongoing efforts to reduce greenhouse gas emissions, warming is expected to continue over the next several decades. Thus, it is now more important than ever to understand how anthropogenic warming will affect future drought conditions, like snowpack. As an important indicator of drought, the snowpack is especially relevant in California for the Sierra Nevada snowpack provides 60% of the state's water via a network of dams and reservoirs. 

Southern California experienced a significant drought from 2012 to 2016, which was exacerbated by warming due to climate change. Defined by unprecedented high temperatures and low annual precipitation, it was the driest four-year span in the last 1,200 years.  As a result, overall vegetation health and cover has most likely been affected (e.g. decline in greenness, high vegetation mortality in chaparral-dominated communities). Changes in vegetation health and cover create favorable conditions for wildfires and landslides. These changes threaten both the stability of the natural environment and the structures that depend on it, such as built electricity generation plants, power lines and pipelines. Because these types of infrastructure are often located on or run through wildland areas, changes in vegetation, wildfires and landslides can impact the region’s energy supplies. To better understand these impacts and assess Los Angeles County’s energy supply vulnerabilities, researchers analyzed the impacts of the 2012-2016 drought on vegetation health and cover using satellite and geospatial environmental data. 

Los Angeles is located in a semi-arid region with finite supplies of local water. The region relies on imported water sources from snowmelt that account for over 85% of the City of L.A. water supply. With climate change leading to declining snowpack and more severe droughts, L.A. County has become more susceptible to water shortage conditions. Thus, to enhance water supply resilience and sustainability across the county, a full characterization of the water budget is necessary. Accurately characterizing the water budget will in turn improve local water resource management and will aid L.A. County to achieve 100% locally sourced water supply by 2050. 

Wastes and biomass residues from agricultural, dairy, forestry and household activities are sustainable energy resources that are widely available and replenishable. They can be used to derive alternative energy products like electricity, heat and bio-jet fuel. However, the transport and storage of waste are costly and processing it requires substantial energy. In order to consider wastes and biomass residues as potential alternative energy sources, there needs to be a holistic assessment of their potential energy production, net energy gain, and greenhouse gas emission reductions. This project aims to undertake this assessment in the contiguous United States.

With climate change, extreme weather events like droughts and heatwaves have become much more frequent in California. Coastal sage scrub (CSS) is a unique ecosystem native to California, which consists of drought-deciduous plants and evergreen shrubs. CSS is a major shrubland type in the Los Angeles region that plays a central role in the conservation of native biodiversity and as recreational areas. These shrubland ecosystems are relatively well adapted to seasonal drought to survive the hot summer months. However, how they will cope with and respond to intensifying water stress, associated with rising temperatures, under climate change is less clear.

The Los Angeles region lies within one of only 36 biodiversity hotspots in the world with more than 4,000 unique native plant and animal species recorded by community science efforts to date. However, development, direct exploitation, climate change, pollution and invasive species threaten our native biodiversity. To better manage our native biodiversity and ensure future generations benefit from the ecosystem services such as food production, environmental health and wellbeing, we need to better understand the breadth of the diversity that exists in our region. Realizing that species conservation efforts must incorporate both evolutionary and genetic data, the UCLA research team will apply genomic tools to assess the genetic diversity of species across the Los Angeles Basin and provide recommendations for effective management strategies to preserve and enhance these critical natural resources.

The Sustainable LA Grand Challenge of UCLA has an ambitious goal of helping transition Los Angeles County to 100% renewable energy by 2050 through innovations in science, technology and policy. An important first step is to determine the balance of accessible renewable energy resources and its distribution and storage. To address this data gap, researchers assessed the 2050 renewable energy potential for the Los Angeles region (defined by the City of Los Angeles, Los Angeles County and the greater metropolitan area, including the surrounding counties) and presented feasible pathways for achieving the 100% renewable energy goal. This study is a preliminary assessment of the energy portfolio for the entire L.A. region.

In 2018, the transportation sector represented over 28%, the largest share, of the total U.S. greenhouse gas (GHG) emissions. Automated vehicles, a rapidly evolving technology, have been modeled to reduce GHG emissions up to 94% and bring accident prevention, smoother traffic and better service to people facing driving difficulties other projected benefits of automated vehicles include reduced infrastructure needs but serving the same demand and potentially more efficient public transportation systems that eliminate transit stops. However, as of 2016 there had not been a field experiment study conducted locally to test and verify the impacts of automated vehicles within Los Angeles County. In this project, researchers ran an automated vehicle prototype on various routes in the county to document the effects on GHG emissions and sustainable transportation.