The biggest emerging economies have ambitious plans that require a greater share of the world’s limited commodities. This trend is spurring profound and permanent disruptions in how these resources are allocated now and in the future. For investors, these disruptions present opportunities. Simply put, an investment in natural resources is a vote of confidence in global economic growth.

Rapid urbanisation and industrialisation, better infrastructure and growing consumption in emerging markets (namely India and China) are among the key themes in the global growth story. They are also key drivers in the rising demand for oil, steel, copper, cement and other resources.

Here are just a few of the many available data points to help gauge the scale of opportunity:

* Just over half of the world’s people now live in cities?that figure is likely to rise to 70% over the next four decades. The urban population in emerging nations has expanded by an average of 3 million per week for the past 20 years.

* India has embarked on a $500 billion plan to expand and upgrade its highways, airports and other transportation assets by 2012.

* More than 13 million cars and light trucks were sold in China in 2009, transforming a land once dominated by bicycles into the largest auto market in the world. Forecasts for 2010 call for vehicle sales to increase by as much as 10%.

India?s GDP growth has resumed its upward trajectory and if central government’s statistics or prominent leaders like finance minister/prime minister are any indicators, India would in the next decade outperform other emerging markets by a big margin. Herein the role of commodity, heavy infrastructure investments cannot be overemphasized.

Another key statistics is India’s rapidly growing middle class (chart). Estimates are that as many as 25% of Indians?more people than the entire US population?fall into this category now, with a doubling possible within the next decade. This trend has huge implications for commodities.

Wealthier people want a better lifestyle. That means more and better housing?in addition to the structure itself (cement, steel), that means more wiring for electricity (copper), more plumbing (copper, zinc) and more basic appliances (steel, copper and other metals). Getting around also means more roads, more bridges, more airports, more and faster railroads—all of which add to commodities demand. While demand is growing, the supply of many key commodities is not keeping pace.

It is increasingly difficult and costly to find and develop large new oil fields, and mining projects are often slowed down by environmental opposition, tighter regulatory requirements, red tapism and slack government attitudes. Many promising new commodity sources are in countries with inadequate infrastructure and/or significant political risks.

Commodity super cycles typically last 20 to 25 year?the current super cycle began in 2000, so we are just at the halfway-mark. A stress in the markets is that insufficient capital has been invested in resources in recent decades, while at the same time the world’s population has doubled and there has been spectacular growth in the middle class. Any supply disruptions quickly lead to price spikes.

There are other reasons to consider an investment in commodities or commodity-based equities, be it through an actively managed natural resources fund or a passive vehicle like an index fund or exchange-traded fund. A lot has been talked about inflation – natural resources are one of the few asset classes that benefit from inflation. If prices for fuel or other commodities rise, one way to hedge against the impact of that price increase is to invest in those commodities. Commodities are also a natural hedge against the erosive impact of a weak dollar. Given massive federal deficits for the next decade, yawning trade deficits and historically low interest rates, it is hard to see how the dollar could see a sustainable rally.

For the reasons detailed above, it is hard to ignore the secular bull market for commodities and natural resources stocks which is underway and could even intensify in 2010, depending on the extent of economic recovery in developed nations.

The writer is a derivatives analyst