ظاهرة الاحتباس الحرارى :-
http://tc.v20.cache4.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor%2Coc%3AU0dXTlhOUV9FSkNNN19QSFVD&fexp=909001&algorithm=throttle-factor&itag=34&ipbits=0&burst=40&sver=3&expire=1289833200&key=yt1&signature=57393FC6EF8E1138C1C0DB4290F18C57F337C66C.CBC4FD24F1270F8D28166DA132867FF47F6975F3&factor=1.25&id=e732eea92605ebc1&redirect_counter=1
الغازات الدفيئة :-
http://v4.cache1.c.youtube.com/videoplayback?signature=4195ADAC75103F5EEA31B42FC490607316BC0EAD.191372F55B7C8AC661E699BF2C8038B930D4DCF8&fexp=909001&ipbits=0&ip=0.0.0.0&id=b66fb364c88be7c0&factor=1.25&sver=3&expire=1289833200&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor%2Coc%3AU0dXTlhOUV9FSkNNN19QSFVD&algorithm=throttle-factor&key=yt1&burst=40&itag=18&playretry=1&redirect_counter=1
http://tc.v20.cache4.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor%2Coc%3AU0dXTlhOUV9FSkNNN19QSFVD&fexp=909001&algorithm=throttle-factor&itag=34&ipbits=0&burst=40&sver=3&expire=1289833200&key=yt1&signature=57393FC6EF8E1138C1C0DB4290F18C57F337C66C.CBC4FD24F1270F8D28166DA132867FF47F6975F3&factor=1.25&id=e732eea92605ebc1&redirect_counter=1
الغازات الدفيئة :-
http://v4.cache1.c.youtube.com/videoplayback?signature=4195ADAC75103F5EEA31B42FC490607316BC0EAD.191372F55B7C8AC661E699BF2C8038B930D4DCF8&fexp=909001&ipbits=0&ip=0.0.0.0&id=b66fb364c88be7c0&factor=1.25&sver=3&expire=1289833200&sparams=id%2Cexpire%2Cip%2Cipbits%2Citag%2Calgorithm%2Cburst%2Cfactor%2Coc%3AU0dXTlhOUV9FSkNNN19QSFVD&algorithm=throttle-factor&key=yt1&burst=40&itag=18&playretry=1&redirect_counter=1