When global mining giant BHP Billiton (BHP -0.42%) reported its results on Feb. 20, the company also updated the market on its view of global commodities. The company always provides great insight into what investors should watch within the commodity marketplace. Let's take a look at the outlook that BHP sees across four of its key commodities.

Copper
According to BHP, the long-term fundamentals of copper remain compelling. While it sees robust supply growth resulting in a balanced market in the near term, the longer-term outlook is much stronger due to structural changes on the supply side of the marketplace. Specifically, it sees a scarcity of advanced, high-quality development opportunities which is further affected as the grades of existing operations are on decline. Basically, there isn't enough top quality copper out there to satisfy the market's future demands.

It sees an average of 1 million tonnes of new supply being required each year to keep up with demand. This likely will cause prices to remain elevated enough to entice the development of lower grade and higher cost supplies. The likely winner here is Freeport-McMoRan (FCX -2.07%) which is one of the world's top copper producers. While the company is diversifying away from copper, it is still investing to grow its production and it has three expansion projects coming online over the next few years.

Iron ore
BHP sees a much more volatile short-term outlook for iron ore. In the past decade, Chinese demand overwhelmed the capacity of low-cost supply which induced producers to produce from higher-cost resources. As more low-cost supply comes online it'll have a greater effect on market prices and likely will bring prices down. Investors in Cliffs Natural Resources (CLF -9.02%) really need to watch this trend closely. The company's shares were pounded by a one-two punch from low commodity prices and an asset write done from an acquisition that hasn't panned out as expected. Further price erosion in the iron ore market could cause more pain to Cliff's bruised investors.

Metallurgical coal
According to BHP, iron ore isn't the only commodity likely to keep Cliffs' shares weighed down. The company sees the price of Cliffs other key commodity, metallurgical coal, remaining range-bound. The sharp price increase in 2011 induced an increase in higher cost U.S. exports, but markets have now rebalanced and prices have reverted back to the mean. If prices do head higher, they could spur U.S. supply, which will only cause prices to fall back down again.

Aluminum
BHP sees aluminum remaining at overcapacity, as Chinese producers continue to expand aggressively. This hurts both Alcoa (AA) and Rio Tinto (RIO -1.19%), which have large aluminum businesses. BHP sees the cost curve continuing to flatten and prices remaining below the marginal cash cost of production. Needless to say, that's not good for the margins of aluminum producers. Rio's big aluminum buy a few years back has continued to prove to be a disaster as the company was forced to write it down by $14 billion last year. In the face of these pricing pressures, Alcoa did state that it expects the aluminum market to grow around 7% globally in 2013 which is slight better than 2012. Determining which company is in the best place to earn this increase in business will be key for aluminum investment in the next few years until supply and demand balance.

My Foolish take
If you believe in BHP's outlook, there is one clear winner, and that's copper. Few companies are better positioned than Freeport-McMoRan to prosper given that outlook. Freeport just happens to be a company in the right commodity at the right time.