Ongoing severe floods are severely impacting rice production worldwide. This constant instability endangers the food security for almost 3 billion people across the globe. Climate change rice crops suffer grave damage when left underwater longer than a week, according to a new study. As a consequence, almost all the plants usually die. This alarming finding underscores the critical need for understanding how climate change and extreme weather events affect staple food production.
Zhi Li, the study’s lead author, explained that it was important to understand how to identify the start and end of a “rice-killing flood.” He stated, “When crops are fully submerged for at least seven days, most rice plants die.” This study marks a new milestone in assessing the cumulative effect of flooding on rice production. From 1980 to 2015, those yields decreased by an average of 4.3%, which represents approximately 18 million tons lost per year.
The study utilized an extensive dataset covering rice growth stages, annual global yields, and historical data on droughts and floods since 1950. On the largest scale, India’s Pennar Basin, where floods increase rice yields—counterintuitive perhaps, but true—can unexpectedly prove beneficial. Yet, in areas—or river basins such as India’s Sabarmati—where flooding has been life-threatening, an obvious crop-killer.
Regions such as North Korea, Indonesia, China, the Philippines, and Nepal have faced increasing threats from rice-killing floods in recent decades. It is quite striking, though probably not surprising, that North Korea, East China, and India’s West Bengal have suffered the biggest total losses. The researchers found that understanding the response of rice crops to both floods and droughts is essential for future food security.
Excessive flooding isn’t the only issue impacting rice yields. Droughts have had a surprisingly large impact as well, averaging an 8.1% drop per year over the same study period. Steven Gorelick, the study’s senior co-author, pointed out that “while the scientific community has focused on damage to rice yield due to droughts, the impacts of floods have not received enough attention.” He admitted that it was a challenge to mitigate these collective effects on rice production.
The study also finds that climate change will almost certainly make extreme floods more frequent in all seven countries that together produce over half of the world’s rice. According to an analysis from Climate Central, that future week of heaviest rain could dump 13% more precipitation. This 36 percent increase, for example, is calculated on averages between 1980-2015.
“Our research documents not only areas where rice yields have suffered due to past flooding, but also where we can anticipate and prepare for this threat in the future.” – Steven Gorelick
Understanding how rice yields respond to a combination of stressors is crucial for safeguarding global food supplies. In light of this study’s findings, policymakers and agricultural experts are called to action. They need to focus on approaches that address these issues and protect the livelihoods of billions who depend on rice for food security.