List of countries by natural gas proven reserves  This is a list of countries by natural gas proven reserves based on The World Factbook (when no citation is given). or other authoritative third-party sources (as cited). Based on data from BP, at the end of 2009, proved gas reserves were dominated by three countries: Iran, Russia, and Qatar, which together held nearly half the world's proven reserves. There is some disagreement on which country has the largest proven gas reserves. Sources that consider that Russia has by far the largest proven reserves include the US CIA (47.6 trillion cubic meters), the US Energy Information Administration (49 tcm), and OPEC (48.81 tcm). However, BP credits Russia with only 32.9 tcm, which would place it in second place, slightly behind Iran (33.1 to 33.8 tcm, depending on the source). Due to constant announcements of shale gas "recoverable" reserves, as well as drilling in Central Asia, South America and Africa, deepwater drilling, estimates are undergoing frequent updates, mostly increasing. Since 2000, some countries, notably the US and Canada, have seen large increases in proved gas reserves due to development of shale gas, but shale gas deposits in most countries are yet to be added to reserve calculations. Comparison of proven natural gas reserves from different sources (billions of cubic meters, as of 31 Dec. 2014/1 Jan. 2015)