balance slowly returned across the land. 大地逐渐恢复平衡

172. there have been more than 50 cycles of ice buildup and melt...
     已经发生50多次结冰融化的循环
173. each causing its own epic floods.
     每一次都引发了大规模洪水
174. Once the turmoil of the last great melt subsided,
     上一次大规模融化引起的混乱 平息之后
175. balance slowly returned across the land.
     大地逐渐恢复平衡
176. Rainfall became more regular...
     降雨变得更频繁
177. allowing forests to bounce back.
     令森林得以复苏
178. Deserts shrunk and greened
     沙漠缩小并变绿

来自《我们星球上的生命 第一季 第八集 Life on Our Planet S01E08 冰与火的世纪》第 175 行