Some people sayearthgetting warmer. They blame something called greenhouse gasses. The greenhouse gasses destroyhigher atmosphere that keeps our planet from getting too hot. CFCs aregasses that cause onethe biggest problemsglobal warming. CFCs destroy somethe ozone thatinhigher atmosphere. The ozone layer helps us by filter out somethe harmful ultraviolet rays fromsun. These rays can cause skin cancerhumans. These rays can also helpheat up our planet. Overpolar ice caps, we now have holesthe ozone layer. These, people believe, contributeworld’s global warming. Oneits effects could haveto speed upmeltingthe polar ice caps. If these melt too quickly,levelthe sea will rise too fastuscontrol it. The effecta risethe heightthe sea will be dramatic. Manythe world’s major cities will be under sea water. So, global warming can be very dangerousour future environment.