The volatility in oil prices over the past decade has created plenty of concern for businesspeople, national governments, and global policymakers alike. With such uncertainty in pricing, coupled with environmental concerns as our world’s appetite for fossil fuels grows, the questions of whether there are enough petroleum oil reserves to satisfy demand, and what the consequences of its extraction will be, have never been more pertinent. In order to shed more light into a somewhat ambiguous subject, we have profiled the ten countries with the largest oil reserves in the world to help put their positions within the energy landscape into perspective. The volatility in oil prices over the past decade has created plenty of concern for governments and policymakers at the global stage. This lack of certainty, coupled with environmental concerns as the world grows ever more energy hungry, the question of whether there are enough petroleum oil reserves to satisfy the demand and what the consequences will be has never been more pertinent. In a bid to shed more light in this somewhat nebulous sector, we have profiled countries with the highest oil reserves in the world. These are the countries whose proven oil reserves are in the top 10 globally.

10. United States - 39,230 million barrels

The oil reserves of the United States (US) soared to new heights in recent years due to increased usage of unconventional drilling methods that enable extraction of more shale oil and gas than was previously possible. As a result of these, especially fracking and horizontal drilling, US reserves surpassed 36,000 million barrels in 2012 for the first time since 1975. Still, proven US oil reserves are but a fraction of the reserves of the global petroleum leaders such as Venezuela, Saudi Arabia, and Canada.

9. Libya - 48,363 million barrels

Libya has the largest oil reserves in Africa and the ninth largest globally. It has the potential to have a greater reserve of fossil fuel than we currently know of, as it remains largely unexplored as a result of past sanctions against foreign oil companies. Libyan oil accounted for 98% of government revenue in 2012 but, due to recent political instability, Libya's power as an oil producer has been significantly hampered. Eventually, it is expected that untapped oil reserves will foster more economic investment as the political situation stabilizes.

8. Russia - 80,000 million barrels

Russia is a country filled with natural resources for energy use, most notably the country's massive oil reserves under the vast Siberian plains. Russian oil output fell considerably after the collapse of the former Soviet Union, but the country has revamped production in the past few years. The nation may further boost its reserves of oil and gas in the future as exploration continues beneath its holdings of arctic waters and ice.

7. United Arab Emirates - 97,800 million barrels

The United Arab Emirates (UAE) sources most of its oil from the Zakum field, which has an estimated 66 million barrels, making it the third largest oil field in the region, behind only Ghawar Field (Saudi Arabia) and Burgan Field (Kuwait). Roughly 40% of the country's GDP is based on oil and gas output and, since its discovery there in 1958, has enabled the UAE to become a modern state with a high standard of living.

6. Kuwait - 101,500 million barrels

While a small country in terms of land area, Kuwait holds more than a fair share of the world's petroleum oil reserves. Over 5 bbl of reserves lies within the Saudi-Kuwaiti neutral zone which Kuwait shares with Saudi Arabia, while over 70 million barrels of Kuwaiti oil are in the Burgan field, the second largest oil field in the world.

5. Iraq - 142,503 million barrels

Despite shaky political situations in its recent history, the country of Iraq sits upon some of the world's largest proven reserves of petroleum crude oil. As a matter of fact, owing to the civil unrest and military occupations which have characterized the national scene over the last few decades, it was not possible to do any meaningful exploration of Iraq's oil reserves. As a result, even the data used to determine Iraq’s global oil holdings ranking is at least three decades old and based on 2D seismic surveys. Nevertheless, a period of relative calm over the last couple of years has given increased hope for developing the country's oil infrastructure.

4. Iran - 158,400 million barrels

Iran has close to 160,000 million barrels of proven oil reserves, making it considerably wealthy in terms of global oil resources. When looking at the most easily accessible reserves (excluding many of the unconventional, difficult-to-extract reserves in Canada), Iran falls right behind Venezuela and the Kingdom of Saudi Arabia.

Oil in Iran was first produced in 1908 and, at its current rate of extraction, Iran's oil will last close to 100 years more. Unlike Saudi oil, which is spread throughout a few huge and very rich oil fields, Iranian oil is found in close to 150 hydrocarbon fields, many of which have both petroleum crude oil and natural gas.

3. Canada - 169,709 million barrels

Canada has almost 170,000 million barrels of proven oil reserves, of which the most significant proportion is in the form of oil sands deposits in the province of Alberta. Furthermore, most of the country's conventionally accessible oil reserves are located in Alberta.

As extracting oil from the vast majority of Canada's oil reserves is a labor and capital-intensive process, production tends to come in sporadic bursts rather than steady streams. Oil companies, therefore, begin by extracting lower density, higher value oils first, and directing their efforts into extracting crude deposits only in times of high commodity prices.

2. Saudi Arabia - 266,455 million barrels

The Kingdom of Saudi Arabia has for many decades been viewed as the modern state most iconic of oils equation to opulence and influence in global politics. However, Saudi Arabia is no longer the world's leader in oil potential.

While the Saudis' 266,455 million barrels of proven oil reserves are marginally smaller than those of Venezuela, all of Saudi's oil is in conventionally accessible oil wells within large oil fields. Moreover, Saudi Arabia's reserves are considered to comprise a fifth of the entire globe's conventional reserves. There are many who also believe that, with further exploration, Saudi Arabia will surpass Venezuela at the top of the proven oil holdings charts. For example, the US Geological Survey estimates that there are well over 100,000 million barrels lying undiscovered beneath the arid sands of Saudi deserts.

1. Venezuela - 300,878 million barrels

With 300,878 million barrels of proven reserves, Venezuela has the largest amount of proven oil reserves in the world. The country's oil is a relatively new discovery. Previously, Saudi Arabia had always held the number one position.

The oil sand deposits in Venezuela are similar to those in Canada. Venezuela also boasts plenty of conventional oil deposits. Venezuela's Orinoco tar sands are significantly less viscous than Canada's, so the oil sands there can be extracted using conventional oil extraction methods, giving it a considerable advantage over the Northern American rival in terms of capital requirements and extractions costs.