Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO 2 and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO 2 treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO 2. The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.

Fundamental understanding of the dependence between the structure and composition on the electrochemical CO 2 reduction reaction (CO 2 RR) would guide the rational design of highly efficient and selective electrocatalysts.Amajor impediment to the deep reduction CO 2 to multi-carbon products is the complexity of carbon-carbon bond coupling. The chemically well-defined catalysts with atomically dispersed dual-metal sites are required for these CÀCc oupling involved processes.H ere,w ed eveloped ac atalyst (BIF-102NSs) that features Cl À bridged dimer copper (Cu 2 )u nits, which delivers high catalytic activity and selectivity for C 2 H 4 . Mechanistic investigation verifies that neighboring Cu monomers not only perform as regulator for varying the reaction barrier,b ut also affordd istinct reaction paths compared with isolated monomers,r esulting in greatly improved electroreduction performance for CO 2 .

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