A 500,000 surplus per year for 5 years is a pretty dramatic statement. I suppose it is possible if the demand demand falls significantly but based on changes to the inventory levels I haven't seen any such indication for 2015. The LME inventory has gone up in 2015 by roughly 170,000 so to meet their target they need another 330,000 surplus for the last 4 months of the year. With all the supply disturptions, it seems to me unlikely but I can't say never.
And the other thing about the 170,000 increase that no analysts ever seems to point out - The starting point for the inventory levels in 2015 was extermely low at 180,000 which is at least the lowest in at least 6 years.

So I agree with Sibu "Just because Goldman Sachs says something, it doesn't mean it is going to happen."

Here a link to a full article with that quote - which mentions Teck as well.

http://www.mineweb.com/news/industrial-metals-and-minerals/when-copper-bites/