Have you ever experienced a severe weather event, like a hurricane or a tornado? Researchers have shown that climate change is causing such weather events to become more extreme and more frequent, destroying communities and infrastructure. To determine which areas are most at risk, researchers from Canada studied the environmental effects of a powerful flooding event that occurred in southwestern British Columbia (BC) in November 2021. 

They focused on a type of severe flooding event that is characteristic of the North American Pacific coastal region, called an atmospheric river. An atmospheric river occurs when a long, narrow vapor cloud flows toward land from the Pacific Ocean, causing heavy rainstorms. In November 2021, an atmospheric river in southwestern BC destroyed numerous regional highways, pipelines, power lines, and railways within its path. Over 18,000 people were evacuated due to flooding, and 6 people died. 

The team explained that before the storm, BC experienced a severe drought and an unprecedented heatwave, followed by widespread thunderstorm activity. In 2021, lightning and human activity caused nearly 1,000 wildfires, which led to the third-worst wildfire season ever recorded in BC, partially because trees grow back slowly in forests that have been cut down or harvested. Poor vegetation recovery makes harvested forests more vulnerable to wildfires than old-growth forests. The November atmospheric river occurred shortly after this wildfire season. 

To determine how the atmospheric river impacted southwestern BC, the researchers analyzed approximately 70,000 square kilometers (27,027 square miles) of affected area. They compared satellite images of southwestern BC from Google Earth, Sentinel, and Landsat taken before and after the event to detect changes in river channels and identify geohazards, like landslides and debris flows. They also used satellite images and Canadian government data to identify which forests had been harvested within the study area. The researchers then traversed the area to confirm their remote analyses. 

The researchers used a type of 3D remote sensing, called light detection and ranging, or lidar, to measure how the 2021 atmospheric river redistributed sediment in the Coquihalla and Coldwater River valleys. With the help of lidar, the researchers discovered that both rivers had severely unstable banks due to erosion from the flooding event. Along the Coquihalla River, approximately 53,000 cubic meters (1,871,677 cubic feet) of sediment were eroded, while nearly 50,000 cubic meters (1,765,733 cubic feet) of sediment were eroded along the Coldwater River. 

The researchers also found that hillslope geohazards increased the volume of sediment in both rivers. And in some cases, upstream areas with a history of forest harvesting and wildfires also affected stable banks downstream. For example, they identified debris flows on an unstable hillslope that triggered a landslide on a riverbank downstream. They observed that the river and stream channels shifted due to a sudden addition of sediment from hillslope geohazards and floodwater during the event.

In total, the researchers documented over 1,300 geohazards along 47 kilometers (about 30 miles) of the Coquihalla River and 19 kilometers (about 12 miles) of the Coldwater River and nearby creeks. Nearly half of the geohazards originated in an area with a history of wildfires or forest harvesting. Of the 155 geohazards at the Coquilhalla River, 43% occurred below forest harvesting resource roads, and of the 117 geohazards observed at the Coldwater River, 29% originated in areas with past wildfires.

The researchers suggested that their findings could help scientists predict where severe geohazards will occur during extreme weather events, since both watersheds had geohazards originating in harvested forests. Before 2000, clear-cutting was a widespread practice in BC, and the team’s results demonstrate that unsustainable harvesting practices like this can have lasting environmental impacts.

The researchers concluded that both forest harvesting and wildfires contributed to the severe impacts of the November 2021 atmospheric river, causing catastrophic landslides and debris flows to occur in traditionally dry regions. They suggested that more accurate risk assessments can better equip communities for severe weather events like this. While the next atmospheric river that lands in the Pacific coastal region may be worse than the last, this study can inform scientists and communities about which areas it might affect most.

The post Wildfires and forest harvesting worsen severe weather impacts appeared first on Sciworthy.

Scientists from Arizona State University have performed computer simulations suggesting viable methods for controlling the weather by ‘nudging” systems in their development stages with proven technologies to mitigate or even completely avoid the damage from extreme weather events.

Although the new approach, which the team termed “Weather Jiu-Jitsu,” hasn’t been tested in real-world conditions, the researchers behind the new perspective paper outlining the process said it could help humans better prepare for severe weather systems by finding ways to live with nature rather than reacting to it.

Controlling the Weather Could Mitigate Property Damage and Loss of Life

When detailing their approach, ASU researcher Qin Huang and colleagues highlight the historical damage caused by extreme weather events, including floods, heat waves, droughts, and ‘freezes.’ In addition to the loss of life, estimates suggest that climate extremes caused $417 billion in damage in 2024 alone.

The paper’s authors also note that such extreme weather events “are increasing in frequency and intensity,” a trend research suggests is strongly driven by rising global temperatures. Although there have been some efforts to mitigate the effects of extreme weather, the paper’s authors write that increasing populations and continued climate change “heighten exposure to risks that conventional infrastructure cannot fully address.”

“The growing impact of weather extremes on society highlights that traditional approaches such as dams, levees, and insurance alone may not be sufficient to address the widespread consequences of these hazards,” the authors write.

To explore alternatives, the team wondered if small adjustments to burgeoning weather systems could redirect their paths or lessen their severity. In some ways, it’s like redirecting an incoming meteor to miss the Earth or hit it at a more oblique angle to lessen the impact.

“Imagine harnessing the power of nature to help steer hurricanes away from land, redirect atmospheric rivers to spread their rain safely and evenly, or defuse extreme weather patterns like heatwaves, freezes, or prolonged droughts before they take hold,” Huang and colleagues write. “It’s a vision where we partner with Earth’s own forces to create resilience, rather than reacting to disasters. We call it Weather Jiu-Jitsu.”

‘Nudging’ Weather System Trajectories with Weather Jiu-Jitsu

When detailing how the process would work, the team explained that Weather Jiu-Jitsu takes advantage of the “chaotic sensitivity of mid-latitude atmospheric dynamics to redirect destructive weather trajectories through small, precisely timed perturbations,” using forecasting models that project system paths and intensities.

“Our thesis is that Weather Jiu-Jitsu, i.e., adaptive chaos control applied to mid-latitude atmospheric dynamics, may provide a 21st century approach to managing a range of extreme weather events by nudging the system trajectories,” they explain.

Due to the challenges and risks of testing weather-control methods in real-world conditions, the researchers developed proof-of-concept computer simulations. Critically, their approach used established models of atmospheric circulation and a large-scale artificial intelligence “deep-learning Earth system” model, Aurora, designed to predict weather at high resolution.

According to the team’s research, carefully timed seeding of clouds could have major impacts on a storm’s path and intensity, noting that “nudges applied days before peak impact can shift a hurricane track to avoid landfall on a major city, weaken the peak intensity of a blocking-driven cold extreme, and reduce atmospheric river moisture transport under favorable upstream conditions.”

When testing their weather control approach on historically extreme climate events, the results were significant. For example, the team found that small, carefully timed cloud seeding operations applied in the critical days before the peak of an extreme weather event “could have shifted the track of the 2012 Hurricane Sandy by about 300 miles to miss New York City.”

The model also indicated that a similar approach could have raised the lowest temperature extremes experienced during the 2021 Texas freeze “by about 18 degrees Fahrenheit.” Similarly, the model revealed that the approach could have reduced the damaging precipitation levels associated with the 2022 atmospheric river that caused flooding in California by about 5%.

“By leveraging the atmosphere’s inherent sensitivity, Weather Jiu-Jitsu seeks not to overpower nature, but to collaborate with it: nudging storm tracks, influencing jet stream meanders, and possibly mitigating compound extremes before they fully develop,” the authors explain.

Revolutionizing the Risk from Extreme Climate Events

When discussing the potential impacts of controlling the weather before serious damage can occur, the study authors noted that it would be “transformative” for the planet. They also noted that controlling the weather could offer an outsized benefit to the most vulnerable people “who do not have recourse to other protections from weather extremes.”

Still, they add that demonstrating the real-world benefits of their approach to controlling the weather while accounting for “natural variability” will require evidence of tangible outcomes. The suggestion is that these metrics would include “reductions in peak precipitation intensity, flood inundation extent, and insured economic losses.”

To achieve this goal, Huang and colleagues recommended a three-stage approach. In the near term, they suggested starting with “controlled deep-learning perturbation experiments” for historical extreme events like floods and droughts, and air them with an “observational system design.” In the medium term, Huang and colleagues suggested implementing “scaled regional pilot studies” and developing a “governance framework development with WMO and UNEP.” The final proposed phase involved limited operational pilot experiments in select locations “under formal international oversight with systematic outcome monitoring.”

“We outline an argument that control over catastrophic weather extremes is imperative to reduce exposure to catastrophic events that are not mitigated by traditional physical, financial, or social infrastructure, and explore conditions under which this may be feasible,” the authors conclude. “If such an approach were successful, it could revolutionize hydroclimatic risk mitigation.”

The study “Weather Jiu-Jitsu: Prospects for atmospheric nudging to defuse the impact of catastrophic weather extremes” was published in PLOS Water.

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.