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2021 Multijurisdictional Local Hazard Mitigation Plan  Heat-related deaths and illnesses in California increased dramatically in 2006 following a record-breaking heat wave. At least 140 deaths occurred between July 15 and August 1. Deaths related to this heat wave were largely attributed to elevated nighttime temperatures.  The number of acres burned by wildfires statewide has been increasing since 1950. Large fires affecting 1,000 acres or more account for most of the area burned each year. San Mateo County and Bay Area Indicators The California Climate Assessment, led by the Governor’s Office of Planning and Research, California Natural Resources Agency, and the State of California Energy Commission, has produced nine regional climate impact and adaptation solution reports. San Mateo County is covered in the San Francisco Bay Area Region. Notable examples of climate impacts in San Mateo County and the broader Bay Area Region include the following (California 4th Climate Assessment; San Francisco Bay Area Report, 2019):  Overall, the Bay Area’s average annual maximum temperature increased by 1.7 °F from 1950 to 2005.  Several studies suggest that coastal fog along the California coast is less frequent than before.  Sea level in the Bay Area has risen over 8 inches in the last 100 years.  The 2015-2016 El Niño, one of the three largest in the historical record, resulted in winter wave energy that was over 50 percent larger than the typical winter in the Bay Area, driving significant outer coast beach erosion.  The 2012-2016 California drought led to the most severe moisture deficits in the last 1,200 years and a 1-in-500-year low in Sierra snowpack. The record low snowpack resulted in $2.1 billion in economic losses and 21,000 jobs lost in the agricultural and recreational sectors statewide and exacerbated an ongoing trend of groundwater overdraft. 17.1.4 Projected Future Impacts Climate change projections contain inherent uncertainty, largely derived from the fact that they depend on future greenhouse gas emission scenarios. Generally, the uncertainty in greenhouse gas emissions is addressed by the presentation of differing scenarios: low-emissions or high-emissions scenarios. In low-emissions scenarios, greenhouse gas emissions are reduced substantially from current levels. In high -emissions scenarios, greenhouse gas emissions generally increase or continue at current levels. Uncertainty in outcomes is generally addressed by averaging a variety of model outcomes. Despite this uncertainty, climate change projections present valuable information to help guide decision-making for possible future conditions. Global Projections The Intergovernmental Panel on Climate Change (IPCC), which includes more than 1,300 scientists from the United States and other countries, project that Earth’s average temperatures will raise between 2.5ºF and 10ºF by over the next 100 years (NASA, 2020a). Some research has concluded that every increase of 2ºF in average global average temperature can have the following impacts (National Research Council, 2011):  3 to 10 percent increases in the amount of rain falling during the heaviest precipitation events, which can increase flooding risks  200 to 400 percent increases in the area burned by wildfire in parts of the western United States  5 to 10 percent decreases in stream flow in some river basins 17-4