Quantcast

Study Finds ‘Underexplored Vulnerability in the Food System’: Jet Stream-Fueled Global Heat Waves

Food
Jet stream triggered heat waves could threaten food production in several important breadbaskets, including central North America. Carl Wycoff / CC BY 2.0

Researchers have pinpointed a previously underexamined threat to global food production, and they warn it will only get worse as the climate crisis intensifies.


The study, published in Nature Climate Change Monday, found that specific wave patterns in the jet stream can trigger heat waves that simultaneously bake parts of North America, Europe and Asia responsible for 25 percent of the world's food, according to a press release published by Columbia University's Earth Institute.

"Normally, low harvests in one region are expected to be balanced out by good harvests elsewhere," study coauthor Dim Coumou of the Institute for Environmental Studies at VU University Amsterdam said in the press release. "These waves can cause reduced harvests in several important breadbaskets simultaneously, creating risks for global food production."

Here's how it works. The jet stream circulates air west to east around the northern hemisphere. Usually, it moves in a relatively straight line, but sometimes it dips north or south. These dips are called Rossby waves, and they can pull Arctic air down to freeze lower latitudes or push tropical air up to bake higher ones. This study was concerned with the baking, and it found two specific Rossby wave patterns that can trigger simultaneous heat waves when they pause in certain predictable locations.

  1. The wave-5 pattern produces five peaks and troughs and stalls over central North America, eastern Europe and eastern Asia.
  2. The wave-7 pattern produces seven peaks and troughs and stalls over western-central North America, western Europe and western Asia.

Because the jet stream is so complex, researchers have only recently been able to understand these patterns.

"Until now, this was an underexplored vulnerability in the food system," lead author and postdoctoral researcher at Columbia University's Earth Institute Kai Kornhuber said in the press release. "During these events there actually is a global structure in the otherwise quite chaotic circulation. The bell can ring in multiple regions at once."

In fact, the researchers found that the risk of simultaneous, extreme heat waves increased 20 fold for the specified regions if either of the two wave patterns was in place. If the pattern persisted for two or more weeks in the summer, food production decreased by an average of four percent across the affected regions and by as much as 11 percent in the individual regions.

Kornhuber said the effects would only get worse with climate change.

This could happen for one of two reasons. First, as the planet warms, heat waves will become more extreme.

"In general, extremes will become stronger, and the likelihood that extremes will occur simultaneously will also increase," Kornhuber told The Washington Post's Capital Weather Gang.

Further, some studies have suggested that the climate crisis might be making the jet stream both more wobbly and more likely to get stuck in these wave patterns. This particular study uncovered global heat waves that occurred in 1983, 2003, 2006, 2012 and 2018, according to the press release. Since most of them occurred after 2000, it is possible that climate change played a role in their frequency, Kornhuber said, but he noted there was not yet enough evidence to say for sure.

Either way, already damaging heat waves will get more severe. The global heat waves documented in the study killed thousands of people in addition to crops and often led to spikes in food prices. This has already contributed to global unrest, as the case of the 2010 heat wave makes clear.

"The 2010 heatwave in Russia caused major harvest failures which led to a national export ban on grains," Kornhuber told the Thomson Reuters Foundation.

This, along with other factors, "contributed to an increase of 50% in (global) wheat prices by the end of the year," Kornhuber explained. "This price spike has been connected to the Arab Spring unrest."

EcoWatch Daily Newsletter

Pro-environment demonstrators on the streets of Washington, DC during the Jan. 20, 2017 Trump inauguration. Mobilus In Mobili / Flickr / CC BY-SA 2.0

By Dr. Brian R. Shmaefsky

One year after the Flint Water Crisis I was invited to participate in a water rights session at a conference hosted by the US Human Rights Network in Austin, Texas in 2015. The reason I was at the conference was to promote efforts by the American Association for the Advancement of Science (AAAS) to encourage scientists to shine a light on how science intersects with human rights, in the U.S. as well as in the context of international development. My plan was to sit at an information booth and share my stories about water quality projects I spearheaded in communities in Bangladesh, Colombia, and the Philippines. I did not expect to be thrown into conversations that made me reexamine how scientists use their knowledge as a public good.

Read More
Mt. Rainier and Reflection Lake on Sept. 10, 2015. Crystal Geyser planned to open a bottling plant near Mt. Rainier, emails show. louelke - on and off / Flickr

Bottled water manufacturers looking to capture cool, mountain water from Washington's Cascade Mountains may have to look elsewhere after the state senate passed a bill banning new water permits, as The Guardian reported.

Read More
Sponsored
Large storage tank of Ammonia at a fertilizer plant in Cubatão, Sao Paulo State, Brazil. Luis Veiga / The Image Bank / Getty Images

The shipping industry is coming to grips with its egregious carbon footprint, as it has an outsized contribution to greenhouse gas emissions and to the dumping of chemicals into open seas. Already, the global shipping industry contributes about 2 percent of global carbon emissions, about the same as Germany, as the BBC reported.

Read More
At high tide, people are forced off parts of the pathway surrounding DC's Tidal Basin. Andrew Bossi / Wikimedia

By Sarah Kennedy

The Jefferson Memorial in Washington, DC overlooks the Tidal Basin, a man-made body of water surrounded by cherry trees. Visitors can stroll along the water's edge, gazing up at the stately monument.

But at high tide, people are forced off parts of the path. Twice a day, the Tidal Basin floods and water spills onto the walkway.

Read More
Lioness displays teeth during light rainstorm in Kruger National Park, South Africa. johan63 / iStock / Getty Images

By Jessica Corbett

Ahead of government negotiations scheduled for next week on a global plan to address the biodiversity crisis, 23 former foreign ministers from various countries released a statement on Tuesday urging world leaders to act "boldly" to protect nature.

Read More