59.8 F

Davis, California

Wednesday, April 17, 2024

Are California’s winters becoming warmer or colder?

Climate scientists and Davis residents discuss climate change and how it’s affecting the season


By SABRINA FIGUEROA — features@theaggie.org


California — known for its warm climate and sunny skies — was hit by a chilling atmospheric river and bomb cyclone on Feb. 1, flooding parts of Southern California and killing nine people. 

Comparing the current winter season to the ones in past decades, winters in California are getting warmer. In the Sacramento Valley, the average winter temperature increased by 2.3 degrees from 1970 to 2022. However small that number may seem, it will have larger implications in the future. 

California is not alone in this. A study done by Climate Central shows that winter was the fastest warming season in 74% of 246 locations observed in the United States. 

Even so, some residents suggest that they feel this change is the opposite. 

“I’ve lived in California all my life,” Prisilla Diaz, a local Davis resident, said. “I do remember there being some storms, but I never experienced them to the point where heavy branches in my backyard are falling. The capacity of the storm [on Feb 1.] definitely took me by surprise. For me, the winter seems a lot colder and longer now.”

Cristina Chambers, a fourth-year psychology major at UC Davis, agreed with this sentiment.

“Coming from Mexico, I didn’t expect the severe [winter] weather,” Chambers said. “I always heard that California was so warm, but not that it was so windy and stormy, so it’s surprising.”

Now the question seems to be: if our seasons are getting warmer, why do we feel like it’s colder, and why are storms much more extreme? 

Dr. Michael Anderson, the official state climatologist for California at the Department of Water Resources, noted that not noticing the temperature change in California is likely due to the fact that it’s happening slowly.

“You really have to look at how the average [temperature] moves. Is it a little bit each day? If every day is just a little bit warmer, then nobody really notices it’s happening,” Anderson said. “Or [are we seeing] periods where it’s just like, ‘Wow, it’s really warm today. It’s 10 to 15 degrees warmer than it should be?’” 

Adding onto this, climate change and the El Niño climate pattern are supercharging the intensity of storms, especially atmospheric rivers — which might be more common in California than you think. Atmospheric rivers are narrow bands of concentrated water vapor in the atmosphere extending from the tropics to mid and high latitudes. It is not unusual for atmospheric rivers to cause floods, landslides and levee breaks, all of which California has experienced this winter.

“It’s a combination of El Niño and global warming as to why the oceans are so warm over such a broad region,” Daniel Swain, a climate scientist at UC Los Angeles, said. “It’s not 100% clear exactly the extent to which each is a relevant player, but they’re both significant. The long-term trend, of course, is mainly because of climate change and the warming of the oceans associated with that.” 

The warming of the oceans from the past year — one of the planet’s hottest years on record — contributed to increased air moisture, causing severe atmospheric rivers and rainfall this season. Additionally, due to the increased level of greenhouse gasses, climate change caused the air to have a larger moisture-retaining capacity as well, according to the Clausius-Clapeyron relationship in thermodynamics. This means that when the atmosphere grows one degree warmer, its capacity to hold water increases by up to 3.9%

So, what does this mean for the future? 

Climate scientists at UC San Diego found that atmospheric rivers will become more “potent” in the coming winter seasons as the climate continues to grow warmer. On the one hand, it is a contributing factor to California’s water supply. However, this also means that as the climate has warmed and droughts have become more frequent, the land is much drier, making it prone to dangerous floods. 

Allison Michaelis, an atmospheric river expert at Northern Illinois University, discussed the changes in storm severity.

“With these atmospheric rivers occurring in succession, it doesn’t leave a lot of recovery time in between these precipitation events,” Michaelis said. “So, it can turn what would have been a beneficial storm into a more hazardous situation.” 

Bomb cyclones, although not uncommon, are now passing through California more than ever before. It’s probable that they will cause more frequent and higher-speed winds in future seasons. 

There are also engineering costs to be taken into consideration. Urban planners currently — and will continue to — face new challenges when it comes to making flood-safe or flood-proof infrastructure. 

“The mentality of the past was that we could control floods and contain where flooding happened,” Brett F. Sanders, an engineering professor at UC Irvine, said. “And outside of that, communities and businesses and residents could kind of go about what they do and not think about floods. But we know now that, around the [United States], we’re seeing that infrastructure is undersized to contain the extreme weather of today.”

However, some things are still left uncertain. Scientists do not yet know if climate change affects how often atmospheric rivers form or where they go. In the meantime, we shouldn’t assume that atmospheric river storms will be bigger than any other storms that occur in the future, according to Samantha Stevenson, an atmospheric and climate scientist at UC Santa Barbara.

Amid all of the uncertainty about the future of climate change, many fear the consequences that come with society not taking action sooner. 

A student shared their feelings about the climate’s current state and its impact on humanity’s future.

“I honestly feel worried because the climate has changed so fast to me; it makes me feel like [humans] went wrong at some point in time,” Chambers said. “I think to myself, ‘If the climate is already degrading right now, what will it be like in 5 years?’”

A resident suggested that as weather and climate change become more extreme in the upcoming years, Californians will not be equipped for the damage it will bring. 

“[Californians] are used to the heat, but extreme winters and the floods that will come with it, are not things we’re used to,” Diaz said. “I feel like California and the entirety of the United States [are] affected by [climate change] in different ways. It would be more sustainable to really think about how to stop it instead of thinking about what we can do as humans to just get through a rainstorm. We need to think long-term.”

Even though it may seem like California’s winter season is becoming colder due to recent extreme weather, the reality is that it’s actually getting dangerously warmer. Learning about these unusual climate patterns will better equip us to mitigate the consequences of global warming as well as bring awareness to them. 


Written by: Sabrina Figueroa — features@theaggie.org


Please enter your comment!
Please enter your name here