But now the mighty lake — a linchpin in a system of aqueducts and reservoirs in the arid U.S. West that makes California possible — is shrinking with surprising speed amid a severe drought, with state officials predicting it will reach a record low later this summer.
While droughts are common in California, this year's is much hotter and drier than others, evaporating water more quickly from the reservoirs and the sparse Sierra Nevada snowpack that feeds them. The state's more than 1,500 reservoirs are 50% lower than they should be this time of year, according to Jay Lund, co-director of the Center for Watershed Sciences at the University of California-Davis.
Over Memorial Day weekend, dozens of houseboats sat on cinderblocks at Lake Oroville because there wasn't enough water to hold them. Blackened trees lined the reservoir's steep, parched banks.
In nearby Folsom Lake, normally bustling boat docks rested on dry land, their buoys warning phantom boats to slow down. Campers occupied dusty riverbanks farther north at Shasta Lake.
But the impacts of dwindling reservoirs go beyond luxury yachts and weekend anglers. Salmon need cold water from the bottom of the reservoirs to spawn. The San Francisco Bay needs fresh water from the reservoirs to keep out the saltwater that harms freshwater fish. Farmers need the water to irrigate their crops. Businesses need reservoirs full so people will come to play in them and spend money.
And everyone needs the water to run hydroelectric power plants that supply much of the state's energy.
If Lake Oroville falls below 640 feet — which it could do by late August — state officials would shut down a major power plant for just the second time ever because of low water levels, straining the electrical grid during the peak demand of the hottest part of the summer.
In Northern California's Butte County, low water prompts another emotion: fear. The county suffered the deadliest U.S. wildfire in a century in 2018 when 85 people died. Last year, another 16 people died in a wildfire.
Walking along the Bidwell Canyon trail last week, 63-year-old Lisa Larson was supposed to have a good view of the lake. Instead, she saw withered grass and trees.
"It makes me feel like our planet is literally drying up," she said. "It makes me feel a little unsettled because the drier it gets, the more fires we are going to have."
Droughts are a part of life in California, where a Mediterranean-style climate means the summers are always dry and the winters are not always wet. The state's reservoirs act as a savings account, storing water in the wet years to help the state survive during the dry ones.
Last year was the third driest year on record in terms of precipitation. Temperatures hit triple digits in much of California over the Memorial Day weekend, earlier than expected. State officials were surprised earlier this year when about 500,000-acre-feet of water they were expecting to flow into reservoirs never showed up. One acre-foot is enough water to supply up to two households for one year...
Climate change in California
Climate change in California has resulted in higher than average temperatures, more temperature extremes, and decreased rainfall, leading to increased occurrences of drought and wildfires. During the next few decades in California, climate change is likely to further reduce water availability, increase wildfire risk, decrease agricultural productivity, and threaten coastal ecosystems. The state will also be impacted economically due to the rising cost of providing water to its residents along with revenue and job loss in the agricultural sector. California has taken a number of steps to mitigate the impacts of climate change in the state.
Paleoclimatological studies indicate that the last 150 years of California's history have been unusually wet compared to the previous 2000 years. Tree stumps found at the bottom of lakes and rivers in California indicate that many water features dried up during historical dry periods, allowing trees to grow there while the water was absent. These dry periods were associated with warm periods in Earth's history. During the Medieval Warm Period, there were at least two century-long megadroughts with only 60-70% of modern precipitation levels. Paleoclimatologists believe that higher temperatures due to global warming may cause California to enter another dry period, with significantly lower precipitation and snowpack levels than observed over the last 150 years.
Extreme weather impacts
A 2011 study projected that the frequency and magnitude of both maximum and minimum temperatures would increase significantly as a result of global warming. The same study further projected that the frequency and magnitude of both maximum and minimum temperatures would likely increase as a result of global warming.
Main articles: List of California wildfires, 2017, 2018, and 2019
In 2017, a study projected that the single largest threat to Los Angeles County hospitals related to climate change is the direct impact of the expected increase in wildfires. In Los Angeles County, 34% of hospitals are located within one mile of fire hazard severity zones. Additionally, one of these hospitals was also deemed in danger of coastal flooding due to the effects of climate change as concluded by the study. This latter issue was also included and focused on, as the study likewise concluded that this would become a greater hazard as sea-level rise due to increase annual temperatures.
As a consequence of further global warming, it is projected that there will be an increase in risk due to climate-driven wildfires in the coming decades. Because of warming, frequent droughts, and the legacy of past land management and expansion of residential areas, both people and the ecology are more vulnerable to wildfires. Wildfire activity is closely tied to temperature and drought over time. Globally, the length of the fire season increased by nearly 19% from 1979 to 2013, with significantly longer seasons in the western states. Since 1985, more than 50% of the wildfire area burned in the western United States can be attributed to anthropogenic climate change. In addition, due to human fire suppression methods, there is a build of fuels in some ecosystems, making them more vulnerable to wildfires. There is a greater risk of fires occurring in denser, dryer forests, where historically these fires have occurred in low-density areas. Lastly, with increases in human population, communities have expanded into areas that are at higher risk to wildfire threat, making these same populations more vulnerable to structural damage and death due to wildfires. Since 1990, the average annual number of homes lost to wildfires has increased by 300%. Almost 900,000 western US residences were in high-risk wildfire areas as of 2017 with nearly 35% of wildfires in California starting within these high-risk areas.
In 2019, after a 'red flag' warning about the possibility of wildfires was declared in some areas of California, the electricity company 'Pacific Gas and Electric ' begun to shut down power, for preventing inflammation of trees that touch the electricity lines. Millions can be impacted. The climatic conditions that cause this warning became more frequent because of climate change. If the temperatures keep rising, such power outages could become common.
The wildfires in 2020 have resulted in the burning of more than 4 million acres in California, which is reportedly double the total of 2018 wildfire statistics, called the record highest. Out of six of the biggest fires in the state of California, five took place in 2020. As a result, 31 people were reported dead and 9,200 structures destroyed, as of 14 October 2020.
Main article: 2011–17 California drought
According to the NOAA Drought Task Force report of 2014, the drought is not part of a long-term change in precipitation and was a symptom of the natural variability, although the record-high temperature that accompanied the recent drought may have been amplified due to human-induced global warming. This was confirmed by a 2015 scientific study which estimated that global warming 'accounted for 8–27% of the observed drought anomaly in 2012–2014... Although natural variability dominates, anthropogenic warming has substantially increased the overall likelihood of extreme California droughts.' A study published in 2016 found that the net effect of climate change has made agricultural droughts less likely, with the authors stating that 'Our results indicate that the current severe impacts of drought on California's agricultural sector, its forests, and other plant ecosystems have not been substantially caused by long-term climate change.'
In February 2014, the Californian drought effects caused the California Department of Water Resources to develop plans for a temporary reduction of water allocations to farmland by up to 50% at the time. During that period California's 38 million residents experienced 13 consecutive months of drought. This is particularly an issue for the state's 44.7 billion dollars agricultural industry, which produces nearly half of all American-grown fruits, nuts, and vegetables. According to NASA, tests published in January 2014 have shown that the twelve months before January 2014 were the driest on record since record-keeping began in 1885. Lack of water due to low snowpack prompted Californian governor Jerry Brown to order a series of stringent mandatory water restrictions on April 1, 2015.
Drought-surviving sugar pines around Lake Tahoe has found among 129 million trees in California killed between 2012 and 2016 by drought and bark beetles. Thousands of seedlings descended from these trees are being planted south-facing slopes on the lake basin's north side with the hope that they carry genes that make them more resilient to drought, waning snowpack and other effects of global warming in the forests of Sierra Nevada.
Extended periods of higher temperatures are expected to increase navel orangeworm reproduction, resulting in increased insect damage to almond, walnut, and pistachio crops.
Conservation groups are partnering with farmers in Central California to flood fields for portions of the year, to increase habitat for species impacted by climate change, such as salmon and migratory birds.
Ocean heatwaves since 2013 have delayed three Dungeness crab seasons, due to harmful algal blooms that contaminate crab meat.
Sea level rise
Population density and low elevation coastal zones in the Western United States
Population density and low elevation coastal zones in San Francisco Bay A 2017 study published in the Journal of Geophysical Research projected that a sea-level rise of between 1 and 2 m will swallow between one-third and two-thirds of Southern California beaches.
Expected increases in extreme weather could lead to an increased risk of illnesses and death. Various diseases will impact Californians as a result of climate change. 'Exposure to wildfire smoke has been linked to health problems such as respiratory infections, cardiac arrests, low birth weight, mental health conditions, and exacerbated asthma and chronic obstructive pulmonary disease.17 Longterm exposure to wildfire smoke generated an estimated $76 billion to $136 billion per year in health costs across the contiguous United States from 2008 to 2012, with some of the most significant impacts in northern California.'
From May to September 1999 – 2003, a study was conducted in nine Californian counties that found that for every 10 °F increase in temperature, there is a 2.6 per cent increase in cardiovascular deaths.
A study of the 2006 Californian heatwave showed an increase of 16,166 emergency room visits and 1,182 hospitalizations. There was also a dramatic increase in heat-related illnesses; a six-fold increase in heat-related emergency room visits, and a 10-fold increase in hospitalizations.
A study of seven counties impacted by the 2006 heatwave found a 9 per cent increase in daily mortality per 10 degrees Fahrenheit change in apparent temperature for all counties combined. This estimate is 3 times greater than the effect estimated for the rest of the warm season. The estimates indicate that actual mortality during the 2006 heatwave was two or three times greater than the initial coroner estimate of 147 deaths.
Research suggests that the majority of air pollution-related health effects are caused by ozone and particulate matter. Many other pollutants that are associated with climate change, such as nitrogen dioxide, sulfur dioxide, and carbon monoxide, also have health consequences.
Five of the ten most ozone-polluted metropolitan areas in the United States are in California. Californians suffer from a variety of health consequences due to air pollution – including 18,000 premature deaths attributed to various causes such as respiratory diseases as well as several other illnesses.
Climate change may lead to exacerbated air pollution problems. Higher temperatures catalyze chemical interactions between nitrogen oxide, volatile organic gases and sunlight that lead to increases in ambient ozone concentrations in urban areas. A study found that for each 1 degree Celsius rise in temperature in the United States, there are an estimated 20–30 excess cancer cases, as well as approximately 1000 excess air-pollution-associated deaths. About 40 per cent of the additional deaths may be due to ozone and the rest to particulate matter annually. Three hundred of these annual deaths are thought to occur in California.
Gross domestic product
The Natural Resources Defense Council estimates that under a business-as-usual scenario, between the years 2025 and 2100, the cost of providing water to the western states in the United States will increase from $200 billion to $950 billion per year, an estimated 0.93–1 per cent of the United States' gross domestic product. Four climate change impacts—hurricane damage, energy costs, real estate losses, and water costs—alone are projected to cost 1.8 per cent of the GDP of the United States, or, just under $1.9 trillion in 2008 U.S. dollars by the year 2100.
A study conducted in 2009 showed that increases in frequency and intensity of extreme weather due to climate change will lead to a decreased productivity of agriculture, revenue losses, and the potential for layoffs. Changing weather and precipitation patterns could require expensive adaptation measures, such as relocating crop cultivation, changing the composition or type of crops, and increasing inputs such as pesticides to adapt to changes in ecological composition, which lead to economic degradation and job loss. Climate change has adverse effects on agricultural productivity in California that cause labourers to be increasingly affected by job loss. For example, the two highest-value agricultural products in California's $30 billion agriculture sector are dairy products and grapes. It is also expected to adversely affect the ripening of wine grapes, substantially reducing their market value.
Main article: Climate change policy of California
California has taken several legislative steps and extensive measures and initiatives targeted at the broader issue of climate effects seeking to prevent and minimize the risks of possible effects of climate change by a wide variety of incentives, measures and comprehensive plans for clean cars, renewable energy, and pollution controls on the industry with overall high environmental standards. California is internationally known for its leading role in the realm of the eco-conscious legislature not just on a national level but also globally.