.left_col {
   float:left;
   width:340px;
   padding-right: 20px;
}
.right_col {
   float:right;
   width:340px;
   padding-right: 20px;

}
.left_col_globalwarming {
   float:left;
   width:241px;
   padding-right: 20px;
}
.right_col_globalwarming {
   margin: 20px 0 0 0;
   float:left;
   width:450px;
}