Quantcast

NASA Scientists: Future Megadroughts Could Last 30+ Years 'Thanks to Human-Induced Climate Change'

Climate

The drought in California, going into its fourth year, has been in the news, especially since California produces much of the country's food. But a new NASA study, published this week in the journal Science Advances, suggests that the U.S. could be looking at much worse. It predicts multi-decade "megadroughts" of more than 30 years by the end of the 21st century if we don't significantly reduce greenhouse gas emissions.

"Recent droughts such as the ongoing drought in California or the Southwest, or even historical droughts such as the Dust Bowl in the 1930s, these are naturally occurring droughts that typically last several years or sometimes almost a decade," said the study's lead author Ben Cook, a climate scientist at NASA's Goddard Institute for Space Studies and Columbia University's Lamont-Doherty Earth Observatory. "What we're seeing is that with climate change many of these types of droughts will likely last for 20, 30, sometimes even 40 years."

How bad these droughts will get is tied to how much greenhouse gas emissions humans generate in future years. Cook and his colleagues say the current risk of a megadrought is 12 percent. If greenhouse gas emissions stop increasing by the mid-21st century, they project the risk at more than 60 percent in the second half of the 21st century. And if they continue to rise at current rates, the researchers say, there is an 80 percent chance of a megadrought in the Southwest and Central Plains between 2050 and 2099. "Alternatively, if the world were to take aggressive actions to reduce emissions, the model still showed drought but the trends would be less severe," they found.

Cook said this study is more robust than previous research, which used fewer drought indictors and few climate models. This study used 17 different climate models, all of which showed a drier planet "thanks to human-induced climate change," says NASA.

"What I think really stands out in the paper is the consistency between different metrics of soil moisture and the findings across all the different climate models," said climate scientist Kevin Anchukaitis of Woods Hole Oceanographic Institution, who was not involved in the study. "It is rare to see all signs pointing so unwaveringly toward the same result, in this case a highly elevated risk of future megadroughts in the United States."

This is also the first study to compare future drought projections to droughts over the last 1,000 years, using tree-ring information to estimate droughts beyond the last 150 years. The researchers looked at megadroughts of 30-50 years that occurred in North America between 1100 and 1300 and compared them with projected late 21st-century droughts. They found that whether greenhouse gas emissions stop increasing or continue to increase at the current rate, the likelihood of drier conditions and droughts lasting 30 years or more is greater.

"We can't really understand the full variability and the full dynamics of drought over western North America by focusing only on the last century or so," said Cook. "We have to go to the paleoclimate record, looking at these much longer timescales, when much more extreme and extensive drought events happened, to really come up with an appreciation for the full potential drought dynamics in the system."

Megadroughts could require adaptations well beyond anything the U.S. has ever faced. Image credit: NASA

Anchukaitis agreed that comparing medieval-era droughts with projected ones is useful.

"Those droughts had profound ramifications for societies living in North America at the time," he said. "These findings require us to think about how we would adapt if even more severe droughts lasting over a decade were to occur in our future."

Those adaptations would be more challenging than anything we've seen in the past, says Cook.

"The droughts represent events that nobody in the history of the U.S. has ever had to deal with," he said. "Even in the modern era, droughts such as the ongoing droughts in California and the Southwest, these normal droughts act as major stressors on water resources in the region. So we expect that with these much longer droughts, it's going to be even more impactful and cause even more problems for agriculture and ecosystems in the region."

YOU MIGHT ALSO LIKE

California Experiences Worst Drought in 1,200 Years

NASA Satellite Images Reveal Shocking Groundwater Loss in Drought-Stricken California

NOAA Report Misses Link Between California Drought and Human-Caused Climate Change

EcoWatch Daily Newsletter

By Jennifer Molidor, PhD

Climate change, habitat loss and pollution are overwhelming our planet. Thankfully, these enormous threats are being met by a bold new wave of environmental activism.

Read More Show Less

President Donald Trump mocked water-efficiency standards in new constructions last week. Trump said, "People are flushing toilets 10 times, 15 times, as opposed to once. They end up using more water. So, EPA is looking at that very strongly, at my suggestion." Trump asked the Environmental Protection Agency (EPA) for a federal review of those standards since, he claimed with no evidence, that they are making bathrooms unusable and wasting water, as NBC News reported.

Read More Show Less
Sponsored
(L) Rushing waters of Victoria Falls at Mosi-oa-Tunya National Park, Zimbabwe pictured in January 2018. Edwin Remsberg / VW PICS / UIG / Getty Images (R) Stark contrast of Victory Falls is seen on Nov. 13, 2019 after drought has caused a decline. ZINYANGE AUNTONY / AFP / Getty Images

The climate crisis is already threatening the Great Barrier Reef. Now, another of the seven natural wonders of the world may be in its crosshairs — Southern Africa's iconic Victoria Falls.

Read More Show Less

Monsanto's former chairman and CEO Hugh Grant speaks about "The Coming Agricultural Revolution" on May 17, 2016. Fortune Brainstorm E / Flickr

By Carey Gillam

Former Monsanto Chairman and CEO Hugh Grant will have to testify in person at a St. Louis-area trial set for January in litigation brought by a cancer-stricken woman who claims her disease was caused by exposure to the company's Roundup herbicide and that Monsanto covered up the risks instead of warning consumers.

Read More Show Less
A volcano erupts on New Zealand's Whakaari/White Island on Dec. 9, 2019. Michael Schade / Twitter

A powerful volcano on Monday rocked an uninhabited island frequented by tourists about 30 miles off New Zealand's coast. Authorities have confirmed that five people died. They expect that number to rise as some are missing and police officials issued a statement that flights around the islands revealed "no signs of life had been seen at any point,", as The Guardian reported.

"Based on the information we have, we do not believe there are any survivors on the island," the police said in their official statement. "Police is working urgently to confirm the exact number of those who have died, further to the five confirmed deceased already."

The eruption happened on New Zealand's Whakaari/White Island, an islet jutting out of the Bay of Plenty, off the country's North Island. The island is privately owned and is typically visited for day-trips by thousands of tourists every year, according to The New York Times.

Michael Schade / Twitter

At the time of the eruption on Monday, about 50 passengers from the Ovation of Seas were on the island, including more than 30 who were part of a Royal Caribbean cruise trip, according to CNN. Twenty-three people, including the five dead, were evacuated from the island.

The eruption occurred at 2:11 pm local time on Monday, as footage from a crater camera owned and operated by GeoNet, New Zealand's geological hazards agency, shows. The camera also shows dozens of people walking near the rim as white smoke billows just before the eruption, according to Reuters.

Police were unable to reach the island because searing white ash posed imminent danger to rescue workers, said John Tims, New Zealand's deputy police commissioner, as he stood next to Prime Minister Jacinda Ardern in a press conference, as The New York Times reported. Tims said rescue workers would assess the safety of approaching the island on Tuesday morning. "We know the urgency to go back to the island," he told reporters.

"The physical environment is unsafe for us to return to the island," Tims added, as CNN reported. "It's important that we consider the health and safety of rescuers, so we're taking advice from experts going forward."

Authorities have had no communication with anyone on the island. They are frantically working to identify how many people remain and who they are, according to CNN.

Geologists said the eruption is not unexpected and some questioned why the island is open to tourism.

"The volcano has been restless for a few weeks, resulting in the raising of the alert level, so that this eruption is not really a surprise," said Bill McGuire, emeritus professor of geophysical and climate hazards at University College London, as The Guardian reported.

"White Island has been a disaster waiting to happen for many years," said Raymond Cas, emeritus professor at Monash University's school of earth, atmosphere and environment, as The Guardian reported. "Having visited it twice, I have always felt that it was too dangerous to allow the daily tour groups that visit the uninhabited island volcano by boat and helicopter."

The prime minister arrived Monday night in Whakatane, the town closest to the eruption, where day boats visiting the island are docked. Whakatane has a large Maori population.

Ardern met with local council leaders on Monday. She is scheduled to meet with search and rescue teams and will speak to the media at 7 a.m. local time (1 p.m. EST), after drones survey the island, as CNN reported.