The burning of fossil fuels and unsustainable use of resources and land have resulted in a gradual increase in global temperatures. Climate change in 2023 indicates that the average global temperature is already 1.1 ℃ higher than before the Industrial Revolution. Regional measurement of carbon emissions is crucial for effectively mitigating climate warming. This study estimates the carbon emissions of the farmland ecosystem in Kaifeng city from 2010 to 2021 based on seven key factors. The findings indicate that overall carbon emissions have fluctuated and increased over time while the carbon emission intensity has decreased annually. Through the calculation of the Tapio decoupling model, it is observed that the decoupling status of the farmland ecosystem in Kaifeng city from 2010 to 2021 has transitioned from weak decoupling to strong decoupling, demonstrating the progress made towards green and low-carbon agriculture in Kaifeng city. Using the grey prediction model GM (1, 1), carbon emissions are estimated to reach 1.39×106 t by 2030. This research provides carbon emission data and trends for the farmland ecosystem in Kaifeng city from 2010 to 2021, explores the decoupling relationship between farmland ecosystem carbon emissions and the economy, and predicts carbon emissions until 2030 under current policies. Based on these findings, recommendations for emission reduction were proposed.