heres the answer
The answer is 
'Time'
The time has come, 
winter is here 
and those yellow bears disapear. 
(...I turn polar bears white )
The time has past 
as man looks back with a sigh 
and a tear in his eye. 
(...and I will make you cry.)
As time is held 
boys cross their legs 
but of course the toilet begs 
(...I make guys have to pee) 
As time marches on 
Girls loose their blush 
and swap a comb for their brush 
(...and girls comb their hair.)
As time passes 
For those held high 
their end is nigh 
(...I make celebrities look stupid )
As time catches up 
Everyone is equal 
when we get to the final sequal 
(...and normal people look like celebrities.)
As time turns 
Without it we have flour and water 
With it we have breakfast for my daughter 
(...I turn pancakes brown )
As time revolves 
How does one turn water and wine 
into something so fine 
)...and make your champane bubble.)
As time runs out 
The more in a minute you try and squeeze 
the less you can do with ease. 
(...If you sqeeze me, I'll pop. )
As time ticks 
All the time that has past 
man cannot comprehand something so vast. 
(...If you look at me, you'll pop. )
Time is the answer