The soil carbon pools were initialized to represent storage and flux conditions in near steady state (i.e., an annual NEP flux less than 0.5% of annual NPP flux) with respect to mean land surface climate recorded for the period 1999-2000.
The palaeotemperature estimates from this study broadly agree with the global mean temperature estimates modeled by Roscher et al. [30], as well as the seasonal mean surface air temperatures during the climate perturbation (mass extinction) event modeled by Kiehl and Shields [26].
Zonal mean surface air temperature in the present climate is well represented by EMICs, at least to a degree similar to GCMs (IPCC [2007]).
The results highlighted the inadequacy of using the global mean surface temperature as the primary yardstick for climate change.
It has been known for some time that the radiative damping rate per unit of global mean surface temperature increase (i.e., global climate feedback parameter) varies with time.
Uncertainty in equilibrium climate sensitivity (ECS), determined by global mean surface air temperature (SAT) increase at a state of climatic equilibrium according to doubling of atmospheric CO2, is an unresolved issue in the climate science (e.g., Knutti and Hegerl 2008).
On the other hand, climate scientists point out that the hiatus occurs in just one component of the climate system - the global mean surface temperature - and that other indicators, such as melting ice and changes to plant and animal life, demonstrate that the Earth has continued to warm.
According to the Fifth Report of the Intergovernmental Panel on Climate Change (IPCC), evidence of climate system warming is unequivocal, and the global mean surface temperatures in 2081 2100 will be up to 3.7 °C higher than those of 1986–2005 under the Representative Concentration Pathway (RCP) 8.5 scenario, with an uncertainty range from 2.6 to 4.8 °C (IPCC 2014).
Using scenarios ranging from business-as-usual to strong longer-term managed decline in emissions, the climate model projections suggest the global mean surface temperature could rise by between 2.8°C and 5.4°C by the end of the 21st century.
Kiehl and Shields [26] modeled terrestrial seasonal mean surface air temperatures for the late Permian during the climate perturbation (mass extinction) event, and estimated a global seasonal mean average temperature ~ 7.98 °C above the current average (~ 23.2 °C).
