The Lake Vostok data showed repeated cycles of global warming and cooling over a 420,000 year period closely correlated with fluctuating CO2 levels, however the 420,000 years of Vostok data showed that the natural fluctuations of CO2 never exceeded 300 parts per million.  Today, the atmospheric CO2 level is 402 ppm.  In the 1830s the atmospheric CO2 levels were 280ppm, so they have increased by 122 ppm in less than 2 centuries, a faster rate of rise (by orders of magnitude) than natural fluctuations ever caused.  Almost all climate scientists believe that the excess CO2 in our atmosphere is anthropogenic, and that that excess CO2 is causing climate change (a very complex process in which the vast majority of excess heat is actually changing ocean temperatures more than air temperatures).  Climate change is happening whether you or Beckster or Trump believe in it or not.