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Drought, Water Supply and Climate Change in the San Diego Region

An update on San Diego’s water supply during the current drought, and how climate change affects regional weather, was the main focus of a recent event sponsored by several organizations.

The Citizens Water Academy, Leaders 20/20 and San Diego Green Drinks hosted a lunch and learn session August 17 that also provided details on how weather and climate impacts water supplies, and how prepared the San Diego region is for drought impacts.

Climate Change-drought-San Vicente Reservoir in San Diego County

Drought, Water Supply and Climate Change in the San Diego Region

An update on San Diego’s water supply during the current drought, and how climate change affects regional weather, was the main focus of a recent event sponsored by several organizations.

The Citizens Water Academy, Leaders 20/20 and San Diego Green Drinks hosted a lunch and learn session August 17 that also provided details on how weather and climate impacts water supplies, and how prepared the San Diego region is for drought impacts.

San Diego County Water Authority General Manager Sandra L. Kerl and National Oceanic and Atmospheric Administration Warning Coordination Meteorologist Alex Tardy spoke to nearly 90 participants via Zoom.

Climate change impacts and drought

Tardy kicked off the event with an overview of how climate change and drought impact regional weather conditions, and what this means for the region’s water supplies.

“Just here in Southern California, we have extreme heat, extreme precipitation and extreme drought,” said Tardy. “In talking about climate and climate extremes, we are not just talking about the obvious ones like temperature, we are also talking about other impacts like more intense storms, more frequent return of droughts and less normalcy.”

His presentation included highlights of how the past several years have included multiple weather extremes, ranging from wettest single days on record to the hottest and driest years. These included precipitation extremes of varying types and impacts, many of which were fueled by El Niño and La Niña weather patterns. Lack of precipitation and increased evaporation have led to record low water supplies in many reservoirs.

Regional drought preparedness

Kerl spoke about drought concerns throughout the Southwest, which include reduced local water supplies, reduced state supplies and Colorado River supply concerns. Governor Gavin Newsom has asked for voluntary 15% reductions in water use and commonsense conservation measures, which are habits already hard-wired in most San Diego County residents.

“The really good news here in our community is that we are prepared for multiple-year droughts – we have sufficient supplies for 2021, and that’s what water bills go to pay for: safe and reliable supplies,” said Kerl. “It’s also important to note that residents and businesses are hard-wired to conserve – the practices are ingrained in the community. Today we use 50% less per capita per day than we did 30 years ago.”

Kerl also highlighted that our region’s diverse water supplies include drought-resistant sources such as desalinated water, and that the San Diego region is prepared and has enough supplies for multiple dry years.

weather extremes in Southern California

Throughout recent years, Southern California has experienced different types of weather extremes that have impacts on water supplies. Photo: Alex Tardy, NOAA/NWS.

Citizens Water Academy

The Citizens Water Academy provides an opportunity for emerging leaders and professionals in the San Diego region to learn about critical projects and programs related to water. Through the academy, the Water Authority seeks to expand and sustain a diverse network of influencers who are willing to serve as ambassadors on water issues and expand knowledge about the region’s water industry. To learn more, go to sdcwa.org/in-the-community/citizens-water-academy.

Leaders 20/20 is a young professionals network that aims to drive civic engagement to ensure a high quality of life in the San Diego region. Leaders 20/20 provides education on important issues affecting the environment and economy and helps professionals build connections to industry leaders: sandiego.edu/soles/hub-nonprofit/initiatives/leaders-2020.php.

San Diego Green Drinks is a social networking group of professionals in the environmental field who attend events to meet industry professionals, find employment or employees, develop new ideas, discuss issues and solve problems.

Watch a recording of the event, starting with Alex Tardy: https://bit.ly/385EGCP

What is La Niña? The Climate Pattern – and How it Affects Our Weather – Explained

So what exactly is La Niña?

The La Niña climate pattern is a natural cycle marked by cooler-than-average ocean water in the central Pacific Ocean. It is one of the main drivers of weather in the United States and around the world, especially during the late fall, winter and early spring.

It’s the opposite to the more well-known El Niño, which occurs when Pacific ocean water is warmer than average.

The Sun May Offer Key to Predicting El Niño, Groundbreaking Study Finds

When it comes to long-term hurricane forecasts, tornado predictions in the Plains or prospects for winter rain in California, you’ll often hear meteorologists refer to El Niño or La Niña. They’re phases in a cycle that starts in the tropics, spreading an influence across the globe and shaping weather both close to home and on different continents.

Now there’s emerging research to suggest that cosmic rays, or positively charged, high-energy particles from space, might be the mechanism that flips the switch between phases. Cosmic rays come from outside our solar system, but the number and intensity that reach Earth hinge on the magnetic field of the sun.

Facing Drought, Southern California Has More Water Than Ever

The cracked and desiccated shoreline of Lake Mendocino made a telling backdrop for California Governor Gavin Newsom’s message at a news conference last week: Drought conditions are here, and climate change makes the situation graver.  But water supplies vary across regions, which is why the governor limited a drought emergency declaration to just two northern counties. In fact, highly urbanized Southern California has a record 3.2 million acre-feet of water in reserve, enough to quench the population’s needs this year and into the next.

Hot Again: 2020 Sets Yet Another Global Temperature Record

Earth’s rising fever hit or neared record hot temperature levels in 2020, global weather groups reported Thursday.

While NASA and a couple of other measurement groups said 2020 passed or essentially tied 2016 as the hottest year on record, more agencies, including the National Oceanic Atmospheric Administration, said last year came in a close second or third. The differences in rankings mostly turned on how scientists accounted for data gaps in the Arctic, which is warming faster than the rest of the globe.

2020 Ties 2016 as Hottest Year on Record, Even Without Warming Boost from El Niño

Global warming pushed temperatures into record territory in 2020, in effect tying 2016 as the hottest year on record, according to data released Thursday by U.S. science agencies.

Last year’s average global surface temperature was 2.2 degrees Fahrenheit above the late 19th century average, according to NASA. It was the fifth consecutive year of more than 2 degrees above that base line. Indeed, the seven hottest years in 140 years of record keeping are the last seven. In descending record order, they are 2020 and 2016, 2019, 2017, 2015, 2018 and 2014.

Many Scientists Now Say Global Warming Could Stop Relatively Quickly After Emissions Go to Zero

Parts of the world economy may have been on pause during 2020, dampening greenhouse gas emissions for a while. But that didn’t slow the overall buildup of atmospheric carbon dioxide, which reached its highest level in millions of years.

If anything, research during the year showed global warming is accelerating. Symptoms of the fever include off-the-charts heat waves on land and in the oceans, and a hyperactive and destructive Atlantic hurricane season.

There’s Hope, SoCal: La Niña Doesn’t Always Mean Drier Winter Weather

There isn’t a one-size-fits-all approach to forecasting climate patterns when there’s an El Niño or a La Niña pattern in place.

El Niño and La Niña patterns are part of the El Niño Southern Oscillation, which monitors sea-surface temperatures in the equatorial Pacific Ocean.

When sea-surface temperatures in this region are above average, it’s called El Niño; when they are below average, it’s called La Niña.

We aren’t talking about major changes in water temperatures but typically more minor swings — usually on the order of plus or minus a degree Celsius — 1.8 degrees Fahrenheit — or less.

There are instances when water temperatures have been as much as eight degrees Fahrenheit above average — a very strong El Niño — but it’s not common.

La Niña: Is California Heading Into Another Drought?

Federal scientists say that La Niña — the phenomenon where Pacific Ocean waters off South America are cooler than normal — is underway this winter.

A commonly held assumption among many Californians is that La Niña means a dry winter is coming, and in years when the opposite occurs, El Niño, a wet winter is considered more likely.

So brown lawns and water rationing are just around the corner, right?

Not necessarily. Looking at historical records, there isn’t a clear pattern. In the Bay Area, La Niña years have been drier than normal only about half the time.