关于英语环保作文,我想问下这个表述对吗?

问题描述:

关于英语环保作文,我想问下这个表述对吗?
Protecting environment is a world-class difficult problem.这里用world-class difficult problem 是否正确?

不太好.供参考
It is difficult to protect the environment across the world.
How to protect the environment has become a world wide headache.
Protecting the environment is a difficult problem for the world.