这句话的关键是理解"and even more so"。even more so并不是一个固定搭配，当然在词典上查不到。看整句的结构，就可以注意到even more so前面的and是一个引导并列句的连词。可是后一分句的主语和谓语呢？这就是so的用法了。这里so是个分句替代词或动词替代词，用来替代前面所提及的分句内容或动词词组。请看下面例句：

--“Has she left?” 

--“I believe so.” [=I believe she has left]

--If you have not yet returned the form, please do so immediately. [=please return it immediately]

知道了so的这种用法，就能很容易的还原第二分句：

And we also need to plan ahead so that we are in a position to deal with the likely levels of climate change which are already inevitable, and even more, we need to plan ahead, too, for the levels that are likely if we don't get those global agreements.

我就不翻译了。此句中get=reach.

“与全球达成共识”也不大妥。谁与全球达成共识？我们就是全球一分子。应为“达成全球共识”。

我的理解跟Expert不同。尤其后半部分的翻译，说实话，我看不太懂。

And we also need to plan ahead so that we are in a position to deal with the likely levels of climate change which are already inevitable, and even more so, too, for the levels that are likely if we don't get those global agreements.

参考译文：我们也需要提前做好计划以便于我们能够应对不可以避免的气候变化可能出现程度/等级，以及如果我们没有获得那些全球协议很可能出现气候 变化等级也是更加如此。

我的理解和翻译如下：

And we also need to plan ahead so that we are in a position to deal with the likely levels of climate change which are already inevitable, and even more so, too, for the levels that are likely if we don't get those global agreements.

【翻译】我们还需要未雨绸缪，以便有能力应对不可避免的气候变化可能出现的不同级别，在我们没有与全球达成共识的情况下，对于气候变化可能出现的不同级别更要如此。

【分析】关键词语：

1. plan ahead：“提前计划”，比喻“未雨绸缪”。

2. are in a position to deal with：有能力处理/应对。

3. the likely levels of climate change which are already inevitable：气候变化可能出现的不可避免的级别。

4. which are already inevitable：定语从句修饰levels，不是climate change。

5. even more so：更是如此。这里so指代前面提及的事情，即：“未雨绸缪”这件事。意思是：“更是应该未雨绸缪”。

6. for the levels that are likely if we don't get those global agreements：“对于气候变化可能出现的不同级别”，这个if条件句，意思是“在我们没有与全球达成协议的情况下”。

7. get those global agreements：这个词组不能翻译成“获得那些全球协议”，这里get 不表示“得到”。该词组表示“与全球达成那些共识”。