Roles of climate feedback and ocean vertical mixing in modulating global warming rate

Abstract Despite the rapid increase of greenhouse gases (GHGs) in atmosphere during past 50 years, observed global mean surface temperature (GMST) showed a pause warming trend first decade twenty-first century. This is referred to as “hiatus”. A dominant hypothesis emphasizes that superimposition cold phase Pacific decadal variability and can lead hiatus. Using simply energy balance models, we explore two potential mechanisms may supress GMST trend: enhanced negative climate feedback downward heat mixing. Forced by linearly increasing heating, stronger reduce rate, but cannot result Downward mixing cause short-lived hiatus rate due nonlinear ocean uptake lower ocean, would be accelerated long run decline rate. study provides further evidence, both theoretically numerically, run, only route contain effectively GHG emissions.