Purpose Climate change continues to garner attention in the public sphere. Most recognize
its potential to affect global carbon (C) dynamics in the biosphere. Many posit that
global warming promotes the decomposition of soil organic C (SOC) and increases soil
C release. However, it remains unclear how soil C dynamics respond to different influencing
factors (e.g., warming method, magnitude/duration, mean annual temperature (MAT) and
precipitation (MAP)) across ecosystems on a global scale. Materials and methods Here,
we performed a meta-analysis to identify the general global patterns of how warming
impacts soil C dynamics. Results and discussion Across all terrestrial ecosystems,
warming reduced SOC by 4.96% and stimulated soil microbial biomass C (MBC), soil respiration
(SR), and heterotrophic respiration (HR) by 6.30, 14.56, and 8.42%, respectively.
Warming affected soil C pools in grasslands and soil C fluxes in forests. The changes
in SOC did not correlate to warming magnitude/duration or climate factors (MAT and
MAP). However, changes in both MBC and SR did correlate to warming magnitude/duration
and MAT. The changes in HR showed a quadratic response to warming magnitude and a
linear response to MAP. Open-top chamber method can effectively affect soil C pools.
SR proved to be more sensitive than HR to most warming methods. Conclusions Our results
showed that soil C release exhibited more sensitivity to warming magnitude/duration
or MAT/MAP than did net soil C sequestration. These results indicate that warming
induces accelerated transition of soils from C sink to C source. Furthermore, they
show the potential for global warming effects to exacerbate the positive feedback
loop in terrestrial ecosystems. However, the declining rates-of-change in SR and HR
under high magnitude warming may mitigate the positive feedback. Our analyses can
improve the predictions of feedback between atmospheric and soil C pools.