Climate Change and Indian Foodgrain Productivity: An Econometric Analysis of the Impact of Temperature Rise, Rainfall Variability, and CO₂ Concentration on Wheat and Rice Yields (1990–2023)

Abstract

How much does a warming climate cost Indian agriculture? This paper exploits three decades of state-level panel data (20 states, 1990–2023) to estimate the causal impact of rising temperatures, increasing rainfall variability, and changing atmospheric CO₂ concentrations on wheat and rice yields — the two crops that underpin India’s food security. Employing Fixed Effects, Random Effects, and system GMM estimators within a Ricardian-Just-Pope production function framework, we find that a one-degree Celsius increase in mean growing-season temperature reduces wheat yield by 6.2 percent and rice yield by 4.5 percent. A one-percentage-point rise in rainfall coefficient of variation depresses rice yields by 5.2 percent and wheat yields by 3.8 percent. The modest CO₂ fertilization effect — roughly 0.8 to 1.2 percent per 10 ppm increase — is far too small to offset thermal damage. The geography of vulnerability is starkly uneven: eastern India (Bihar, Odisha) and central India (Madhya Pradesh, Maharashtra), where irrigation coverage remains low and farms are small, exhibit vulnerability indices of 4.2–4.8 on a five-point scale, while the canal-irrigated northwestern plains (Punjab, Haryana) score a comparatively resilient 2.5–2.8. Under the IPCC’s business-as-usual trajectory (RCP 8.5), India could lose 28.3 percent of its wheat production and 22.5 percent of its rice production by mid-century — a prospect that would jeopardize food security for 1.6 billion people. Irrigation expansion, heat-tolerant varietal development, and climate-smart agricultural practices emerge as the three most consequential adaptation levers.

DOI:  https://doi-ds.org/doilink/05.2026-46135191