Climate change impacts rice in East Asia

A recent study reveals a growing concern for farmers and consumers in East Asia: rice quality is being affected by rising nighttime temperatures due to climate change.

Led by researchers from Shaanxi Normal University and the Laboratory of Climate and Environmental Sciences (France), the study analyzed more than 35 years of data on rice quality in China and Japan.

The results indicate that nighttime temperatures above 18°C ​​in China and 12°C in Japan significantly reduce rice quality, as measured by indicators such as the whole grain rate (HRR).

In China, rice quality has shown a consistent decline since the 1980s, while in Japan the decline was most pronounced between 1996 and 2010.

The projection is even more worrying: under moderate to high emissions scenarios, rice quality will continue to decline through 2100, with China facing the most severe impacts.

Why is nighttime temperature crucial?

The study highlights that rising nighttime temperatures interfere with the grain filling process, reducing grain transparency and increasing the rate of chalky grains. This phenomenon compromises not only the commercial value of rice, but also its culinary and nutritional properties.

In Japan, where short-grain crops are predominant, the reduction in quality is directly reflected in a lower proportion of grains classified as top quality. In China, southern regions such as Guangdong and Hainan are already facing greater vulnerability due to warmer climate conditions.

Adaptation: an urgent need

To mitigate the impacts, the authors suggest investing in genetic improvement programs to develop more heat-tolerant cultivars. In addition, agricultural management strategies, such as adapting the planting calendar, can help minimize damage.

More information can be found at doi.org/10.1029/2024GL110557