The respiratory exchange ratio (rer) is a way of determining the body's metabolism of:

The respiratory   exchange ratio  (RER)   is  a  way  of   determining  the   body  metabolism  of  carbohydrate  and  fat.
   The   respiratory   exchange  ratio   is  the ratio  between  the  amount  of  carbon  dioxide  produced  and  oxygen  used. Measuring  this  ratio   can  be  used  to  estimate  the  respiratory  Quotient (RQ)  which  an  indicator  of  which  carbohydrate or  fat  is  being metabolized  to  supply  the   body  with    energy.

Very minute and important evidence needs to be collected in order together detail and figure out what had happened

No because the eaeht is on a 23.5 degree axis tilt and so when it is winter the northern hemisphere is pointing away from the sun and the soutubern hemisphere is pointing toward the sun