Apocalyptic weather combination could occur twice as often by 2100 – study

Samantha Stevenson followed suit Santa Barbara in October 2017. Two months later, the Thomas Fire swept through Ventura and Santa Barbara County, the place she called her new home. Three weeks later, a rainstorm she described as “devastating” raged, killing at least 21 people with debris flows. The fire had burned away plants and roots, leaving loose soil that quickly eroded during heavy rain.

“You’re moving to a new city and you don’t know anyone and suddenly there’s this huge fire and the air is full of smoke and ash is raining down on my car,” she says The opposite. “It was a shocking reception in California.” Stevenson says she was in a part of Santa Barbara furthest from the fires, and while she didn’t have to evacuate her home, she felt the conditions that affected the fire like smoky, ashy air.

Many others are still feeling the effects of that fire. Stevenson points to Montecito as a community that has been hit even harder. Stevenson is just one of thousands of people who witnessed this natural disaster.

The Thomas Fire and subsequent rainfall is just one such event that inspired a study co-authored by Stevenson, a professor of climate science at the University of California, Santa Barbara. She and her team published their findings in the journal today scientific advancessuggesting that climate change could make this vicious cycle of wildfires followed by violent storms more likely later this century.

What’s new – Two climate models discussed in the paper predict that by the mid-21st century, in a high-warming scenario known as RCP8.5 (Representative Concentration Pathway), there could be an increased likelihood that an extreme fire event would result in at least one extreme follows precipitation event this year. By the year 2100, these common events could double in frequency in California and be more than seven times as likely in the Pacific Northwest. RCP8.5 is considered the worst-case scenario of climate change as the planet’s temperature rises.

“In a way, the results are in line with what we expected,” says Stevenson The opposite. “We’ve known for some time that climate change is increasing the risk of wildfires and extreme precipitation.” While these two extremes are very rare on their own, the effects of climate change may make both events more likely.

Stevenson emphasizes that we are not currently living the path that RCP8.5 is taking us. “There’s some evidence that we’re on a path that’s a little more moderate than RCP8.5 right now,” she says. That may bring some relief, but we’re still at the beginning of the century, so there’s room for fluctuation.

Why it matters – While Stevenson and her team made a forecast under a worst-case scenario, it means that even a more moderate trajectory could generate a higher probability of these extreme weather events. They may not be as likely as their worst case scenario paper suggests.

Whether the probability increases only slightly or sevenfold, more events like the Thomas Fire may occur, potentially devastating other communities. The western US is particularly prone to this weather, considering that these fluctuations occur regularly in the region.

To go into detail – A climate model, says Stevenson, is a large set of equations. There’s an equation for the ocean, for the atmosphere, for humidity, and so on. Each equation describes how that variable behaves. Depending on the behavior and the corresponding equation, the model then examines how all of these variables interact with each other. It is not a set of weather forecasts, but a statistical model that examines the likelihood of a variable’s behavior and how that behavior may lead to future events. For example, a climate model cannot predict exactly when and where a forest fire will next break out, but depending on the information given to it, it can indicate the likelihood that a fire will occur in a given region during a given time period.

“That way you can say, ‘Maybe the fire wouldn’t have happened over here, maybe it would have happened here instead,’ but the statistics on the impact of climate change will be consistent across all these simulations.

For example, hot and dry temperatures—prolonged by increased global temperatures—favor wildfire weather. The longer these conditions persist, the longer the fire season can last and the more difficult it can be to control the fire.

What’s next – Plants and vegetation play a modest but crucial role in this delicate balance. The absence of flora and their root systems gives way to erosion, which can lead to landslides and even the destruction of houses by boulders. A large part of the risk that wildfire poses is related to how quickly vegetation can regrow. Stevenson says having plenty of plants regrow in the first few months after the fire is less of a concern because it reduces the risk of debris flows.

The way fires destroy plants is another variable that can be incorporated into climate models. “Ultimately, what we need to do next is try to think about the full spectrum of interactions between fire, precipitation, plant growth, and eventually fine-scale topography.”

Leave a Reply

Your email address will not be published.