I have never been to Japan but I have lived in China for almost 2 years.
What Rillifane ( above ) has said is correct. All of these FACTS can be easily checked with a search on the internet. China now produces MORE co2 than the USA. ( Check it ) !
Many people come to China with the beliefs that they have been taught about the country all their lives. Those beliefs are WRONG. They usually enjoy the first six months or so and think everything is new and exciting, different people culture ( ? ) etc. Then they start to see the reality of this country and simply LEAVE. VERY FEW stay for more than 12 months, ask yourself WHY?
The people here are unlike ANY others that I have encountered when travelling in Asia. They have been so cut off from the rest of the world that their culture ( ? ) has developed in isolation and is quite unique. You will find their manners and hygiene standards rather unusual to say the least! I also find them extremely selfish and willing to make money at ANY cost to others. ( Search the China daily for SLAVES ! )
I would suggest that you try to visit here before you decide to re locate. If you do, then I suggest you take a long hard look at the PEOPLE here and not just the " sights " and remember that what seems to be " Local colour " when you are on your holiday soon becomes a cause of disgust and anger when you have to live surrounded by it everyday.
As a " Foriegner " you will be constantly stared and laughed at, you will constantly be over charged for goods and services ( If they can get away withit ) and you will be subjected to ridicule and racism.
The Govt. here is now running ads, on TV teaching / asking the people to be clean, friendly and respectfull to each other ! Why is that ? The Olympics are coming and they are afraid the world will find out the truth about the reality here
If you would like to know more about the awfull truth of this country please feel free to email me. ( If this posting is not reported by some Chinese person trying to hide the TRUTH ).
To those that tell you China is a " wonderfull country " simply ask " Why do 70% of Chinese students, who go to study abroad, NEVER return " ? ( Search The China daily )
Good luck with your decision.
Also DO NOT take any notice of the Chinese people that post on this board as they will give you a totally FALSE impression of their country and will only tell you the " positive " things ( as they see them ) NEVER the " negative " becauase that's what they have been taught to do all their lives.