Abstract:
Many studies discussed climate change without considering the complexity of climate system. In our view,
climate system is a complex and non-linear system. It possesses all properties that a complex system will have,
such as non-linearity, chaos, catastrophe, multiple stable or unstable equilibrium states, etc. It is increasingly
obvious that the equilibrium state of climate system is being broken by destructive human activities. There are
several possibilities that global climate will proceed. We would not exactly predict what outcome will finally
occur if destructive human activities continue. In the farther future, in addition to the scenario of continuous
warming, there is also possibility that the climate would proceed and reach a new stable or unstable
equilibrium state, and the new equilibrium state would be realized in a smooth and continuous way, or realized
in an abrupt way by jumping or plummeting. Recent years’ and the coming tens of years’ unusual change in
global climate would be a prelude for dramatic climate change in the far future. We found that global annual
mean temperature since 1880 has been rising in sinusoidal-type, similar to a superposition of sine curve and
exponential curve, in which a periodicity of about 60 years existed and in the first ~40 years the temperature
rose and in the second ~20 years it declined or approximately to be constant. Accordingly, we predicted that
the global annual mean temperature had reached a peak around 2005, and would decline or be approximately
constant until around 2030. Some models, equations and parameters on climate change were also developed
based on past hundreds of years’ historical records.