Anshveer Bedi, James Burrell, and Alexander Flores, University of San Francisco
Punjab is facing a pressing yield problem. Despite being a vital agricultural hub in India, making up 11% of the country’s agricultural output, Punjab has witnessed severe yield fluctuations for key staples like rice, maize, and wheat over the past three decades. These fluctuations are caused by Punjab’s shifting climate, particularly the increase of hot weather days, rainy spells, and other climatic anomalies. Crop yields have seen increasing volatility over the years, often as high as 10% for rice and wheat and averaging roughly 20% for maize. While many factors influence crop yields, including fertilizers, soil quality, technology, and pests, there is a compelling causal link between temperature shifts and abrupt yield fluctuations. Changes in climate can alter crop production, which could cause food insecurity in India and other trading partners relying on Punjab’s output.
As Earth approaches a 2-degree Celsius rise from pre-industrial levels, phenomena such as hot days, rainfall, and flooding are expected to become more frequent. This global trend has manifested in Europe, where agricultural yields have declined due to floods, EWDs (Extreme Weather Days), and elevated temperatures. In fact, the number of global flood occurrences has increased by approximately 198% since 1990, and surface temperatures have seen an average increase of 0.17 degrees Celsius per decade from the 1970s to the 2000s.
Punjab’s agriculture provides a firsthand view of how climate change affects regional farming. In 1988, Punjab saw 2000 mm of rainfall, an increase of 1200 mm from the year prior. The resulting floods decimated crop yields, resulting in a 29.8% decrease in yield for maize relative to 1987. Roughly two decades later, an increase in hot weather days caused a smaller, yet still substantial, decrease in agricultural yields. Using Google Earth Engine to pinpoint hot weather days (i.e., days with temperatures over 32 degrees Celsius), we found that Punjab experienced 16 more hot weather days in 2006 than in the previous year, which coincided with a decrease in the wheat yield of roughly 4.9%. Then, in 2008, rice crop yields fell by 0.78% as relative humidity spiked by 6% from the year prior. Higher relative humidity often harms yields by hindering transpiration, negatively impacting plant growth by disrupting cell enlargement.
Punjab’s agricultural challenges have profound implications for India and its trading partners. India’s agricultural sector is already stagnating—the sector only experienced annual growth of 1.6% between 2005 and 2017, compared to an average of 3% annual growth in the prior 20 years. This trend, only exacerbated by local weather shifts, casts a looming shadow of food insecurity, economic instability, and escalating poverty across India and beyond. The introduction of wheat export bans in an attempt to preserve domestic food production also raises concerns about the food security of key trading partners like Indonesia, Bangladesh, and China, considering that India’s export volume currently sits at a staggering 39 billion dollars.
Given that climate change poses an existential threat to agriculture in Punjab, a strategic pivot toward climate resilience is imperative. Developing and deploying climate-resilient crop varieties could help pave the path forward. Investing in agricultural research and development is crucial to breeding and producing crops that can endure temperature extremes, drought, and flood conditions. Moreover, enhancing early warning systems and climate forecasting capabilities will empower farmers with critical, timely information, enabling informed decision-making regarding optimal crop patterns, irrigation schedules, and preventative measures. However, implementing these strategies necessitates comprehensive support for farmers—government education and training on new technologies and practices is essential.
Urgent action is clearly needed to address the challenges associated with climate change: The fate of Punjab, and the world more broadly, hangs in the balance.