scientist have proven that the sun has a natrual process of heat up and cooling down so i think thats its just a natrual process of the universe ... sure us humans arent helpin any but we have mostly been doing the same thing for many decades and it just now starts i dont think so ..

Don't cha love history lessons? Well, to get you updated, mankind has just started to get technologically advanced. And when we do get advanced, our methods of advancing like flying high like a bird, or going faster than a speeding cheetah, or dive deep like the sperm whale, all of these, boosts, no matter how helpful they are, will impact our ambience in a region. Water is fluid. CO2 also acts fluid, hence, ghg's. We are changing the boundaries of natural elements. Oil, precious metals, land development, supplying facial tissues etc. Which are all excreting wastes, and not taking in energy. We are rearranging enormous amounts of weights around.

Real scientist don't anticipate much effect from carbon dioxide at all, much less "increasingly critical". Atmospheric carbon dioxide's greenhouse effect is logarithmic -- the first half of pre-Industrial Revolution-level effect was achieved by less than 20 parts per million, then needing the addition of 250 ppmv more to achieve the same warming increment to reach pre-IR effect and it will take a massive increase to repeat the dose again. (The "how much" depends on total sensitivity estimates but, utilizing A Field Guide to the Atmosphere (Houghton, 1983)'s commonly cited 7 K greenhouse effect for 300 ppmv (presumably from Kondratyev & Moskalenko but the origin of this common figure is obscure) then quadrupling pre-IR levels to 1120 ppmv can deliver a mere 1.71 K warming in total -- since there's already alleged to have been 0.7 K that leaves just 1 kelvin potential for adding another 740 ppmv to the current 380 ppmv.)