The terrestrial biosphere plays a pivotal role in removing carbon from the atmosphere. The removal processes are primarily affected by the presence of extreme temperature in the atmosphere. Little information is available on carbon removal response by the terrestrial biosphere during extreme temperature events over the Indian region. India has witnessed frequent and intense heatwaves in the recent past, and future projections about the frequency of heatwave occurrence suggest a further increase in the changing climate scenario. This study used surface CO₂ flux observations and satellite retrieved columnar and mid-tropospheric CO₂ concentrations to understand atmospheric CO₂ variability and its transport patterns with anomalously high-temperature events such as heatwave conditions over India. Intensification of temperature up to 32 °C has increased the atmosphere-biosphere CO₂ fluxes (carbon sink). But further intensification in temperature (> 32–33 °C), like those observed during heatwaves, tends to drive the ecosystem to act as a CO₂ source into the atmosphere due to reduced ability to absorb atmospheric CO₂. Such excess CO₂ fluxes may lead to change in the atmospheric CO₂ concentration via atmospheric circulation or the vertical transport of the air masses from the near-surface to the upper levels in the atmosphere. The satellite observed CO₂ concentration is elevated by 2–3 ppm during the heatwave conditions over India. The impact of extreme temperature on the biospheric sink capability in the carbon cycle, leading to an increase in the atmospheric CO₂ concentration, is one of the significant outcomes of this study.

陆地生物圈在从大气中去除碳方面发挥着关键作用。去除过程主要受大气中极端温度的影响。关于印度地区极端温度事件期间陆地生物圈的碳去除响应的信息很少。印度最近见证了频繁而强烈的热浪，未来对热浪发生频率的预测表明气候变化情景将进一步增加。本研究使用地表 CO ₂通量观测和卫星反演的柱状和对流层中部 CO ₂浓度来了解大气 CO ₂异常高温事件（例如印度上空的热浪条件）的变异性及其传输模式。温度升高到 32 °C 会增加大气-生物圈 CO ₂通量（碳汇）。但温度进一步升高（> 32–33 °C），就像在热浪期间观察到的那样，由于吸收大气 CO _{2 的}能力降低，往往会促使生态系统成为进入大气的 CO ₂源。这种过量的CO ₂通量可能通过大气环流或气团从近地表到大气高层的垂直输送导致大气CO ₂浓度发生变化。卫星观测到的 CO ₂在印度的热浪条件下，浓度升高了 2-3 ppm。极端温度对碳循环中生物圈汇能力的影响，导致大气 CO ₂浓度增加，是本研究的重要成果之一。