In Earth's earliest atmosphere, methane and carbon dioxide occurred at much higher levels than at present-a circumstance that was favorable for early life.(在地球最早的大氣層中，甲烷和二氧化碳的含量比現在要高得多，這對早期生命來說是有利的。)

Although the system would consume energy, it would return energy to the grid via methane generation from composting nonedible parts of plants.(盡管該系統會消耗能源，但它會通過從植物不可食用的部分堆肥產生的沼氣將能源回饋給電網。)

Many environmental experts now believe that methane is more responsible for global warming than carbon dioxide.(許多環境專家現在認為，甲烷比二氧化碳對全球變暖負有更大的責任。)

When our Sun later became hotter, the continued removal of atmospheric carbon dioxide and methane by early bacteria kept Earth's climate from becoming too hot to sustain life.(當我們的太陽后來溫度變得更高時，早期細菌持續清除大氣中的二氧化碳和甲烷，使地球的氣候不至于變得太熱而無法維持生命的存在。)

Therefore, the methane now emitted from open landfills should instead be burned to produce electricity.(因此，現在從露天垃圾填埋場排放的甲烷應該被用來發電。)

The large amount of methane contained in the atmosphere surrounding Neptune stained it blue.(圍繞海王星的氣層內所含大量甲烷將它染成了藍色。)

Other ancient bacteria consumed methane, greatly reducing its amount in the atmosphere.(其他古代細菌消耗甲烷，大大減少了甲烷在大氣中的含量。)

Methane and propane are alkanes.(甲烷和丙烷是烷烴。)

Far from the sun, in the outer solar system, beyond Jupiter's orbit, temperatures are low enough to permit ices to form out of water and out of gases like methane and carbon dioxide.(在遠離太陽的外太陽系，在木星軌道之外，溫度低到足以使冰從水以及甲烷和二氧化碳等氣體中形成。)

The burning of methane generates carbon dioxide that is released into the atmosphere.(燃燒甲烷產生二氧化碳，然后釋放到大氣中。)