The allure of China's rapidly growing economy has been enticing investors with potential riches for years. However, while its stock market has certainly produced some stunning investment returns, those returns have come with an outsized portion of risk. Not only has China's stock market been extremely volatile, but its investment oversight isn't exactly on par with that of Western economies, which has burned investors more than once.

One way investors can avoid these risks altogether is by investing in Western companies that are benefiting directly from China's growth. Topping that list are commodity producers, as these companies are mining and selling base metals like copper, iron ore, and aluminum to satiate China's commodity-hungry economy. While demand for these commodities is weakening due to a slowdown in China's growth rate, the overall growth in commodities shipped to China isn't expected to end anytime soon. That's a trend that will drive future growth for top commodity producers Freeport-McMoRan (NYSE:FCX), BHP Billiton (NYSE:BHP), and Rio Tinto (NYSE:RIO), making the trio the three best stocks to invest in China's growth.

Copper-driven growth
Over the next decade Chinese demand for copper is expected to grow from roughly 12 million tonnes per year to more than 18 million tonnes per year, as noted on the top chart in following slide.

Source: Freeport-McMoRan Investor Presentation.  

As is also noted on that slide, overall global copper growth over the next decade is expected to be a very robust 28%. That is a much faster growth rate than the previous decade, despite coming off of a larger base. It's also worth pointing out that by 2024 Chinese demand for copper will almost eclipse total worldwide demand for the metal in 2004. Further, this growing demand will be affected by supply challenges, as existing mines won't be able to keep up with demand due to expected production declines. This indicates that there will be plenty of growth opportunities for copper producers Freeport-McMoRan, BHP Billiton, and Rio Tinto in the near future.

This is why all three companies are investing now to grow copper production. Freeport-McMoRan, which is already the largest publicly traded copper company, is in the middle of a multi-billion dollar copper expansion phase, which will boost its copper production from its current rate of 960 million pounds to nearly 1.4 billion pounds next year. Further, the expansion will push its unit net cash cost from $1.62 per pound all the way down to $1.20 per pound. Not to be outdone, 30% of BHP Billiton's major growth capital and about 10% of its exploration capital is being invested in future copper projects, while Rio Tinto is investing heavily in the Oyu Tolgoi project, which will drive future copper production growth.

Lots of heavy lifting still to do
China is also expected to drive growing demand for steelmaking commodities like iron ore and metallurgical coal. The Chief Executive of Rio Tinto's Diamonds & Minerals division, Alan Davies, recently pointed this out in a speech when he noted that, "When it comes to crude steel, China need only grow its production by 1% a year to be at 1 billion tonnes by 2030." That suggests it will need a growing supply of iron ore and metallurgical coal to continue to produce steel, which is exactly what we see in projected iron ore demand in the following slide.

Source: Rio Tinto Investor Presentation.  

That's a trend that plays right into the strengths of both BHP Billiton and Rio Tinto, as they are two of the top three iron ore producers in the world. Further, both are among the lowest cost producers as well, which is key for surviving turbulent commodity prices.

Investor takeaway
Investors looking for the best way to invest in China's growth should consider investing in the companies that produce the commodities it needs to drive that growth, with the three best being Freeport-McMoRan, BHP Billiton, and Rio Tinto. What makes these three the best is the fact that they are not only among the largest producers in the world, but are all among the lowest cost producers. That will yield better profitability over the long-term, which is what drives strong returns for investors.