Mechanism Of Cenozoic Climate Change

The driving forces of Cenozoic climate change varies with time.On million years scale,the main driving force for the climate change over the last 65Ma is plate tectonic.On 10,000 years scale,the Quaternary climate change over the last 2.6Ma is regulated by the solar insolation and global ice volume changes.Since the mid-Pleistocene revolution?0.9 Ma?to present,global climate change is characterized by primary 100kyr cycles,which was proposed to be produced by the ice volume changes.On years scale,the climate change over the last 5 decades is recorded by massive instrumental measurements.Intensity of anthropogenic activities over the last five decades is far higher than any historic time.The anthropogenic carbon dioxide?CO₂?is believed to be the main cause of present global warning.The Earth is a complex system and changes in Earth's interior,surface and outer space all have potential impact on the Earth's climate.It's very important to find out the main force of climate change from the possible answers.Climate itself sometimes may also affect the possible driving force,it is very hard to find the final answer or clarify the cause and the effect.Here we will work on the Cenozoic,Quaternary and present climate change to explore the essential driving forces of these changes and further testify the conclusions of past studies.Our studies on the million years climate changes shows that the rhythms for the climate over the last 65Ma have 13Myr periodicity.Moreover,the variations of the duration of geomagnetic chrons and the subduction rate of plate also have such 13Myr cycles.We propose that speedy plate subduction reach the core and mantle boundary trigged the changes of heat flow.It is the heat flow that reach the earth's surface by mantle plume and cause climate changes by feedback process.Our study on the Quaternary climate change on the Chinese Loess Plateau shows that the Winter monsoon on the Asian inland have primary 41 kyr cycle and secondary 100 kyr cycle between 450 and 50 ka.The 41kyr is proven to be paced by the integrated winter insolation at 50°N where the center of Siberia High locates.The result indicates the Asian inland has its own distinct driving force besides the ice volume changes.We also work on the climatic anomalies on the Chinese Loess Plateau around the L1S,S5,L9 and L15.Our result suggest that that all occur at the periods when the geomagnetic field intensity correlates negatively with the ice volume changes.On years scale,the comparisons between the growth rate of CO₂ and temperature suggest that CO₂ usually lags behind the temperature.The high correlation between CO₂ and temperature have other potential mechanism besides the greenhouse effect of CO₂ rising temperature.We propose that anthropogenic CO₂ causing global warming has yet to be testified before used on political and economic negotiations.As a summary,our studies revealed the essential factors of Cenozoic climate change,find new driving force for the Quaternary climate changes and offer an alternative explanation for the present climate change.