Disastrous duo: heatwaves and droughts

Disastrous duo: heatwaves and droughts

Simultaneous heatwaves and droughts are becoming increasingly common in western parts of the Unites States, according to a new study led by researchers from McGill University. Periods of dry and hot weather, which can make wildfires more likely, are becoming larger, more intense, and more frequent because of climate change.

In a study published by Science Advances, the researchers analyzed heat and drought events across the contiguous United States over the past 122 years. They found that combined dry and hot events have not only increased in frequency, but also in size geographically. Where such events were once confined to small parts of the United States, now they cover whole regions, such as the entire west coast and parts of the Northeast and Southeast.

“Dry-hot events can cause large fires. Add wind and a source of ignition, and this results in ‘megafires’ like the 2020 fires across the west coast of the United States. Drought and record-breaking heatwaves, coupled with a storm that brought strong winds and 12,000 lightning events in a span of 72 hours, caused more than 500 wildfires,” says lead author Mohammad Reza Alizadeh, a PhD student under the supervision of Professor Jan Adamowski in the Department of Bioresource Engineering at McGill University.

The researchers also found that dry and hot weather events are intensifying, with longer periods of drought and higher temperatures. These dual “dry-hot extremes” are not only self-intensifying – more heat causes more drought and vice versa – but are also self-propagating, meaning they are able to move from region to region. “As increased temperatures are driving and expanding aridity, droughts and heatwaves move from one region to downwind regions,” says Alizadeh. These extremes can be particularly damaging for agricultural production and ecosystems, they warn.

According to the researchers, the trigger for these hot-dry events is shifting. Looking back at the catastrophic Dust Bowl of the 1930s, they explain that the dust storms were driven by a lack of rainfall coupled with poor land management practices. In recent decades, however, dry-hot disasters are driven more often by excess heat than a lack of rainfall.

The future will bring us more of these disasters, if the current warming trends continue, the researchers caution. They suggest their findings could be used to inform climate mitigation and adaptation efforts. “We need to understand how things are changing in order to adapt,” says Professor Jan Adamowski.

About the study

“A century of observations reveals increasing likelihood of continental-scale compound dry-hot extremes” by Mohammad Reza Alizadeh, Jan Adamowski, Mohammad Reza Nikoo, Amir AghaKouchak, Philip Dennison, and Mojtaba Sadegh is published in Science Advances.

DOI: https://doi.org/10.1126/sciadv.aaz4571



from ScienceBlog.com https://ift.tt/3jioUII

Comments

Post a Comment

Popular

Words Matter When Discussing Alcohol Issues: A New Stigma-Free Vocabulary for Better AUD Outcomes

Image
Word choice may seem out of place among the myriad factors that can influence outcomes for a complex condition like alcohol use disorder (AUD). In fact, the stigma created by the language that is used to describe alcohol problems can decrease many people’s willingness to seek help for alcohol problems. It also can affect how people with AUD are treated in all aspects of life. “Stigmas are the negative attitudes toward people that are based on certain distinguishing characteristics,” says National Institute on Alcohol Abuse and Alcoholism (NIAAA) Director George F. Koob, Ph.D. “More than a decade of research has shown that stigma contributes significantly to negative health outcomes and can pose a barrier to seeking treatment for mental illness or substance use disorders.” In the United States, nearly 90 percent of people with substance use disorders and 35 percent of people with serious mental illness do not receive treatment. In a recent article published in  Neuropsychopharma...
Read more

‘Massive-scale mobilization’ necessary for addressing climate change, scientists say

Image
A year after a global coalition of more than 11,000 scientists declared a climate emergency, Oregon State University researchers who initiated the declaration released an update today that points to a handful of hopeful signs, but shares continued alarm regarding an overall lack of progress in addressing climate risks. “Young people in more than 3,500 locations around the world have organized to push for urgent action,” said Oregon State University’s William Ripple, who co-authored “The Climate Emergency: 2020 in Review,” published today in Scientific American. “And the Black Lives Matter movement has elevated social injustice and equality to the top of our consciousness. “Rapid progress in each of the climate action steps we outline is possible if framed from the outset in the context of climate justice – climate change is a deeply moral issue. We desperately need those who face the most severe climate risks to help shape the response.” One year ago, Ripple, distinguished profess...
Read more

Researchers advance science behind gut health and prebiotics

Image
When it comes to improving human gut health, approaches and the success of these approaches are based largely on an individual’s gut ecosystem: the bacteria present, its diversity and other factors. Therefore, trying to improve gut health through application of prebiotics or probiotics can have wildly variable results based on gut flora composition. Bruce Hamaker , director of the Whistler Center for Carbohydrate Research and Distinguished Professor of Food Science, and Thaisa Moro Cantu-Jungles, his postdoctoral research associate, recently discovered a way to select prebiotic fibers that have the potential to provide improvement of gut health where everyone would benefit. Their study, conducted in vitro, showed an increase in butyrate-producing bacteria with a selected fiber using this new approach. Butyrate is a short-chain fatty acid that supports many of the body’s essential functions from regulating the immune system to digestive health. In donors’ gut flora where these bacter...
Read more