Very few people notice that it is warmer in countries with wide open spaces than in cities. This may be because of the buildings and skyscrapers that fill these places, structures that are nonexistent in those with grass fields and meadows. This claim has actual basis because the buildings and skyscrapers themselves act as structures that shade everyone from the harmful rays of the sun. This is a good thing and is beneficial to the inhabitants of places such as these, because they are kept out of the sun's reach by these structures themselves. What other people do not know is that buildings and skyscrapers are not the only ones which protect them from the ultraviolet rays of the sun - there are also the thick clouds of smoke and fog that proliferate in the atmosphere. Because they act as barriers that block the heat of the sun, one might say that this is beneficial - and it is, too. The problem is that they add up to the dirty air humans have to breathe in everyday to be able to