Actually science can tell us BOTH the how and the why.  EVERYTHING around you that has been made by humans has science behind it and built into it.  It has allowed us to evolve, technologically, from stone age primitivity to today's wireless connectivity in a relatively short period of time.
The sun is emphatically NOT warming (it is cooling) - where do you get these "alternative facts?"  And the fact that the sun's irradiance has DECREASED over the last 30 years or so while the Earth's temps have increased make all the more remarkable our impact on it.
Science CAN predict the future, depending on what you want to predict.  The weather is fairly easy, the climate is not so easy.  But we also know how long our sun will last and what will happen to it when it "dies" billions of years from now.  Not bad, eh?