Well it's not as if the earth's axis will shift, it is simply a choice in clothing, you may as well ask "What if you decided to wear a dress shirt instead of a polo shirt?"Obviously there is a deeper meaning in our hearts to the tartans we wear, a connection to our ancestors for some, for others it's all about comfort. Therefore a question like that can only be answered by the individual. Rest assured though if I were to wear trousers today the sun would rise tomorrow.