對一段話的理解

Some environmentalists question the prudence of exploiting features of the environment, arguing that there are no economic benefits to be gained from forests, mountains that no longer exist. Many environmentalists claim that because nature has intrinsic value it would be wrong to destroy such features of the environment, even if the economic costs of doing so were outweighed by the economic costs of not doing so.

這段話的意思好像，保護環境可能沒有經濟上的意義。但環境有其自身價值。我不明白最後一句話。最後一句應該翻譯成“毀壞環境的經濟代價高於不毀壞環境的經濟代價”?outweigh，該怎麽理解?