Multiple Global Change Stressors Boost Soil Greenhouse Gas Emissions Worldwide.

Soil carbon greenhouse gas (GHG) emissions are integral to climate security worldwide. Global change is known to impact soil GHG emissions; yet, the contribution of an increasing number of global change factors (GCFs) to the rates of carbon GHG emissions remains virtually unknown, challenging our capacity to forecast the trajectory of climate change. Here, we synthesize 1803 observations on soil CO2 and CH4 fluxes across 21 types of GCFs spanning a wide range of ecosystems (i.e., forests, grasslands, farmland, wetlands, tundras, and deserts) and found that an increasing number of GCFs will result in significant increases in CO2 and CH4 emissions. The impacts of GCFs on GHG emissions were largely explained by climate, biome types, and GCF-induced changes in soil moisture, providing potential tools for managing global change. Our work provides critical insights, emphasizing that the number of global change stressors needs to be immediately reduced to help minimize the negative impacts of carbon greenhouse gas emissions on climate change.