So in selecting targets of 450 parts per million and selecting two degrees at the climate negotiations, what we have done is we've made an ethical choice.
因此，在选择把450ppm作为大气中二氧化碳含量的警戒线 以及协商把两度作为气候变化指标的过程中， 我们的所作所为是一个道德方面的选择。