This is no time to wallow in negativity.

不要浪费时间让自己沉浸在消极情绪中了。

2.put bluntly 坦率地说，坦白说

Put bluntly, we are headed for about another 0.5c of warming whatever we do.

坦白说，不管我们现在做什么，温度都将再升高0.5度。