Thermal response of Earth's climate to atmospheric GHGs is delayed in time. The magnitude of time delay can significantly exceed several decades, while current thermal imbalance of Earth is likely to amount 0.6 K but it can increase to 5 K by 2100. The paper provides modelling analysis of dynamical behaviour of global warming and presents climatic hysteresis diagrams. Transient simulations reveal that time delay depends on Earth's thermal capacity and mass, and on conductive and convective heat transport. It is concluded that the effect of GHGs warms climate and simultaneously suspends the glaciation/interglaciation cycles that periodically occurred in the past.