GUNR provides exposure to the rising demand for natural resources and tracks global companies in the energy, metals and agriculture sectors, while maintaining a core exposure to the timberlands and water resources sectors.

GQRE, which debuted in November 2013, tracks the Northern Trust Global Quality Real Estate Index, a fundamentally-weighted index that focuses on commercial and residential REITs. Mortgage REITs, real estate finance companies, mortgage brokers and bankers, commercial and residential real estate brokers and real estate agents and home builders are among the securities that are excluded from the index. [Rookie REIT ETF Shines]

NFRA tracks the STOXX Global Broad Infrastructure Index and includes traditional utility, energy and transportation subsectors of the infrastructure category, along with communications and government outsourcing/social infrastructure, which should help further diversify the portfolio.

Much of the developed world, including the U.S., and plenty of emerging economies have vast infrastructure needs that will require trillions of dollars of expenditures in the coming years.

Investors can capitalize on that trend with an increasing number of internationally focused exchange traded funds. Fortunately for conservative investors, playing the global infrastructure theme does not mean having to incur the increased volatility of a pure emerging markets fund because several global infrastructure ETFs feature deep developed markets exposure. [ETFs for Increased Infrastructure Spending]