Yourenvironmentconsists of the particular natural surroundings in which you live or exist, considered in relation to their physical characteristics or weather conditions.

considered修飾什么詞？

Your environment consists of the particular natural surroundings in which you live or exist, considered in relation to their physical characteristics or weather conditions.

considered 的邏輯主語也是句子的主語：Your environment。

這是過去分詞短語作“條件或緣由狀語”。等于：

Your environment consists of the particular natural surroundings in which you live or exist, if/becauseit is considered in relation to their physical characteristics or weather conditions.

（這里it 指Your environment）

【翻譯】你的環境由你存活的特定自然環境組成，（假如/由于）考慮到它們的物理特點或天氣條件。