This is partly because trees cannot grow forever: China’s economy could not continue to get 10% bigger every year. And in part, it is because growth is not unconditionally desirable: Citizens may be better off with a little less of it, and more clean air.
这部分是因为树木不可能永远向上长：中国经济无法继续以每年10%的速度扩大。另一部分原因是增长并不是无条件值得追求的东西：增长略低但空气更清新，公民的生活会变得更加美好。