What A Megadrought Would Mean for the Agriculture Economy

The term “megadrought” can be a mixed bag for agricultural professionals. Headline-grabbing terms like megadrought can help draw public attention to the severity of drought in the West.

What really matters to lenders and investors is how the agricultural industry responds to it, and whether or not conditions call for a different set of risk mitigation measures than a “normal” drought.

As of April 2021, several major news outlets have used the term “megadrought” to refer to the “driest 19-year span since the late 1500s.” But a recent Mashable article calls it a “fuzzy term with no standard definition” and argues that “belaboring the nomenclature doesn’t change what really matters: The drought is exceptionally dry and intense, and human-caused warming is likely playing an outsized role.”

This article will take a look at what a megadrought would really mean for the agricultural industry, and how better preparation — through data collection, collaboration, and water conservation — can mitigate the worst of its effects.

Megadrought History

The main characteristic of a megadrought is that it lasts for several decades — by most definitions, two decades or more. The term doesn’t refer to the severity of the drought, only the length — which is why major droughts like the Dust Bowl aren’t typically referred to as megadroughts by scientists — although the two factors are often linked. As a result, megadroughts can present chronic physical risks to the agricultural sector.

Megadroughts may be linked to the La Niña phenomenon in the Pacific Ocean and can be identified in the historical record by using tree rings, fossil corals, and sediment core samples. Based on this data, some scientists believe that megadroughts played a role in the decline of the Mayan civilization, and may have been a frequent occurrence in North America, especially during the Medieval Warm Period (950 – 1250).

The study of historical water patterns is known as paleohydrology. Because many key sources of water data, such as streamgages, have only been used for the past century or so, they “capture a limited number of extreme events and may not contain the full range of variability,” explains the U.S. Bureau of Reclamation.

By incorporating data from tree rings and other sources, scientists can get a more complete picture of how drought has shaped the American West:

“A longer record of past droughts can inform water managers about the types of droughts, and level of risk, to consider in planning studies and can complement the use of future projections of how climate change may impact drought severity and duration.”

The Impact of Climate Change on Megadroughts

While some aspects of megadrought can be linked to natural variability, a recent report in Science magazine describes a clear correlation with human activity. Scientists used tree ring data to compare soil moisture during the 2000 – 2018 period with earlier dry periods and found “a more extreme trend toward megadrought as global warming continues.” In fact, it accounts for as much as 46% of drought severity.

As Forbes puts it, “if not for the warming climate this could be a regular drought and not a megadrought.” This is largely due to the fact that warm air retains more moisture than cool air, resulting in more evaporation and drier soils.

Recent soil moisture levels have been at their lowest levels since the megadrought that lastest from 1575 to 1603 — a 28-year period that was bookended by abnormally wet periods.

A surprising fact that emerged from the study is that “the 20th century was the wettest century in the entire 1200-year record.” This suggests that natural climate swings will continue to happen, and that anecdotal evidence of wet and dry periods simply can’t take the place of hard data.

Ag professionals need a combination of real-time water data and an understanding of drought history to mitigate business risk.

Implications for the Agricultural Economy

The main concern for ag professionals when it comes to a megadrought is the length. While some of the same risk mitigation and water conservation strategies will apply to any drought, it’s the sheer duration of a megadrought that will test the stamina of an operation’s water infrastructure and the stability of the agricultural sector overall.

As the Public Policy Institute of California explains, California’s ecosystems evolved to withstand short-term droughts, but the longer the drought, the more the impacts add up.

For example, “the warm, dry 21st century accelerated declines in … native biodiversity, and contributed to extensive tree deaths in headwater forests.” This results in a loss of ecosystem services that are integral to soil quality and water health.

Additionally, while reservoirs can be replenished quickly, it takes more time to recharge an aquifer. A megadrought would put a prolonged strain on existing water resources and reduce a farmer’s ability to maintain water-intensive crops. This would put pressure on lenders who haven’t already worked with their borrowers to reduce water risk.

Investing in water infrastructure and risk mitigation strategies ahead of time can reduce the impact of a megadrought when it occurs. It also contributes to the sustainability of farming operations, resulting in better financial health and ROI in the long run.

Solutions and Preparedness Come from Proactivity

Scientists may not always agree on when a specific dry period meets the criteria of a megadrought, but it’s important for ag professionals to read the reports, consider the implications of scientific models, and be proactive about acting on them.

With better data, the agricultural industry can learn from the past, reduce the harm caused by a megadrought, and set itself up for long-term sustainability.

A megadrought is a real possibility, and by some accounts, is already happening. The fact that the research can stay one step ahead and provide advance warning of a megadrought is promising. It means that the alarm has already gone off, and with the right steps, the worst of its impacts can be mitigated.

Ag professionals can start by gathering the right data, securing and improving water infrastructure, and strengthening relationships with borrowers. By breaking down siloed data and ensuring that all stakeholders have access to reliable, transparent data, ag lenders and investors can lead the industry to a more water-resilient future.

The Bottom Line

Droughts have always been a reality in the American West, and recent studies suggest that megadroughts — those that last for two decades or more — have occurred several times over the last few millennia. It’s the sheer duration of a megadrought that has the greatest impact, putting pressure on water supplies and agriculture infrastructure.

AQUAOSO helps ag professionals mitigate these risks with our cloud-based Water Security Platform that can analyze dozens of water data layers throughout the American West. Users can integrate real-time data with historical data to monitor trends in an intuitive, map-based format, and share reports with other stakeholders for collaborative decision-making.

Contact the team today to schedule a demo of the Water Security Platform, download the Drought white paper, or visit the Resources page to learn more about drought risk in agriculture.

Recent Posts