The projection of China＇s near- and long-term future climate is revisited with a new-generation statistically down- scaled dataset, NEX-GDDP （NASA Earth Exchange Global Daily Downscaled Projections）. This dataset presents a high-resolution seamless climate projection from 1950 to 2100 by combining observations and GCM results, and re- markably improves CMIP5 hindcasts and projections from large scale to regional-to-local scales with an unchanged long-term trend. Three aspects are significantly improved： （1） the climatology in the past as compared against the ob- servations; （2） more reliable near- and long-term projections, with a modified range of absolute value and reduced inter-model spread as compared to CMIP5 GCMs; and （3） much added value at regional-to-local scales compared to GCM outputs. NEX-GDDP has great potential to become a widely-used high-resolution dataset and a benchmark of modem climate change for diverse earth science communities.
Equilibrium climate sensitivity （ECS） is usually defined as the global mean equilibrium temperature response to a doubling CO2 concentration of its preindustrial level in the atmosphere[Hegerl et al., 2007;Meehl et al., 2007].
According to the IPCC Fourth Assessment Report （AR4） [IPCC, 2007], the global mean surface temperature in 2100 is projected to be 1.1-6.4℃ higher than the 1980 1999 mean state, with the best estimation of increase at 1.8-4.0℃. It should be noted that this is the projected range of increase rather than the so-called uncertainties in global warming projection. Specifically, 1.1℃ and 1.8℃ are the lower limit and the best estimation for the B1 emissions scenario （the low emissions scenario）, respectively; while 4.0℃ and 6.4℃ are the corresponding upper limit and the best estimation for the A1F1 emissions scenario （the high emissions scenario）. Therefore,
The planetary wave response to global warm ing with single forcing of greenhouse gases （GHGs） is investigated in this study by using a total of 11 model results that anticipated CMIP3 4XCO2 experiments. It is shown that the amplitudes of the planetary wave fluxes over Siberia, the Eastern North Pacific, and the North Atlantic decrease by approximately -10% to -30% in the warming context. In particular, the vertical wave flux over the Eastern North Pacific significantly decreases by -28.6%. The weakening of the planetary waves is partly associated with the decreased land-sea thermal contrast, which may be caused by the radiation effect of CO2 and the different surface heat capacities of land and sea. The present work provides a clear understanding of the re sponses of planetary waves to GHGs forcing.
