Flash droughts may completely destroy an area’s crops if they occur at the wrong time and grow quickly.
Additionally, as the world heats, they are occurring more frequently.
In a recent research that was released on May 25, 2023, we discovered that in the upcoming decades, the probability of flash droughts, which may emerge in only a few weeks, is expected to increase in all of the world’s key agricultural regions.
By the end of this century, crops in North America and Europe that had a 32% yearly probability of a flash drought a few years ago might have as much as a 53% annual likelihood. As a result, there would be increased demand on water, energy, and food production. Damage costs will also increase. In 2017, a flash drought in the Dakotas and Montana resulted in agricultural losses in the United States of $2.6 billion.
How flash droughts develop
Every drought starts when the rain stops. The intriguing thing about flash droughts is how quickly they perpetuate themselves, perhaps with a little assistance from global warming.
The soil rapidly loses moisture in hot, dry weather. As temperatures rise, this “evaporative demand” might increase as dry air draws moisture from the soil. The absence of rain during a flash drought might also affect the feedback mechanisms.
Crops and flora start to perish considerably faster under these circumstances than they do during regular long-term droughts.
Global warming and flash droughts
In our recent work, we assessed the future drought risks under three scenarios for how rapidly the world implements policies to curb global warming using climate models and data from the last 170 years.
We discovered that agriculture in most of North America and Europe will have a 49% and 53% yearly likelihood of flash droughts, respectively, by the last decades of this century if greenhouse gas emissions from automobiles, power plants, and other human sources continue at a high rate. Globally, Europe and the Amazon are predicted to see the biggest growth rates.
Although reducing emissions can greatly lower the danger, we discovered that under a low-emission scenario, flash droughts will still rise by roughly 6% globally.
Timing is everything for agriculture
Numerous flash drought occurrences have occurred in our lifetimes, and they are unpleasant. People are hurt. Crop losses occur for farmers. Cattle may need to be sold by ranchers. A brief drought in 2022 reduced barge traffic on the Mississippi River, which transports more than 90% of agricultural exports from the United States.
An whole crop might be destroyed if a flash drought happens at a crucial time in the growing season.
For instance, during the silking stage of its blooming cycle, corn is most susceptible. That often occurs during the sweltering summer. The effects of a sudden drought are likely to be severe if it happens then. Farmers, however, might actually benefit from a flash drought closer to harvest since it makes it easier for them to access the fields with their equipment.
Winter wheat in the southern Great Plains is most at danger when it is sown, in September to October of the year prior to the crop’s spring harvest. We discovered significantly lower yields the next year when we examined flash droughts that occurred in that area during that fall’s sowing season.
Paddy rice, a food staple for more than half of the world’s population, is under jeopardy in northeast China and other regions of Asia. at Europe, other harvests are at danger.
Flash droughts can also have a severe impact on ranches. Cattle ran out of fodder and water became more limited during the severe flash drought that hit the central United States in 2012. Cattle lack nourishment if it doesn’t rain during the natural grasses’ growth season, and ranchers may be forced to sell off a portion of their herds. Timing is everything once more.
It extends beyond agriculture. Water and energy supplies may also be at danger. The severe summer drought that hit Europe in 2022 began as a flash drought before growing in scope as a heat wave developed. The troubles in the area got worse when water levels in certain rivers dropped so low that power plants had to shut down because they couldn’t access water for cooling. Such incidents offer a glimpse into the problems that nations are currently dealing with and may face in the future.
Although not all flash droughts will be as severe as those that occurred in the U.S. and Europe in 2012 and 2022, we are worried about what may lie in store.
Can agriculture adapt?
Enhancing rainfall and temperature predictions, which may assist farmers in making important decisions like whether or not to plant, is one method to help agriculture adjust to the increased danger.
Farmers and ranchers are interested in knowing the weather forecast for the upcoming one to six months when we speak with them. When it comes to making projections for the next several weeks or longer using computer models, meteorology is quite good. However, flash droughts develop across a medium time span that is hard to predict.
Along with other scientists, we are tackling the problem of observing and enhancing the lead time and accuracy of forecasts for flash droughts. The United States Drought Monitor, for instance, has created an experimental short-term map that can show the emergence of flash droughts. Forecasting and monitoring methods will become more accurate as scientists understand more about the factors that create flash droughts, as well as their frequency and intensity.
Raising awareness can also be beneficial. Short-term projections that indicate a region is unlikely to get its typical precipitation should instantly raise red flags. The likelihood of a flash drought emerging increases if forecasters also anticipate rising temperatures.
With the increase in global temperatures, nothing is becoming any simpler for farmers and ranchers. They, as well as everyone involved with water resources, will be better able to handle yet another difficulty in the future if they are aware of the risk from flash droughts.
Jordan Christian is a postdoctoral researcher in meteorology at the University of Oklahoma, and Jeff Basara is an associate professor of meteorology there.