What is the climate in most of northern africa like? (site 1)?

The climate in most of northern Africa is humid with short cool summers and long cold winters\\

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen