Over time landfills can be removed , especially those in hot climates , so as to stop leachate contamination of potential groundwater sources and to stop landfill gasses being released to atmosphere where methane is 23 times more harmful than carbon dioxide 以后垃圾掩埋法將被淘汰(特別是在熱帶氣候中)以防止可能的地下水源滲漏液污染與沼氣釋放到大氣中,如果沼氣含量擴大23倍,則比二氧化碳的危害更大。