Carbon dioxide (CO2) is a problematic greenhouse gas, although its conversion to alternative fuels represents a promising approach to limit its long-term effects. Here, pyroelectric nanostructured materials are shown to utilize temperature-variations and to reduce CO2 for methanol. Layered perovskite bismuth tungstate nanoplates harvest heat energy from temperature-variation, driving pyroelectric catalytic CO2 reduction for methanol at temperatures between 15 °C and 70 °C. The methanol yield can be as high as 55.0 μmol⋅g-1 after experiencing 20 cycles of temperature-variation. This efficient, cost-effective, and environmental-friendly pyroelectric catalytic CO2 reduction route provides an avenue towards utilizing natural diurnal temperature-variation for future methanol economy.