Europe buys one-quarter of its total natural gas from Russia, and despite recent geopolitical tension, ratings agency Fitch believes it will not shake that dependence for the foreseeable future. "Any attempt to improve energy security by reducing European reliance on Russia would require either a significant reduction in overall gas demand or a big increase in alternative sources of supply, but neither of these appears likely," a recent report from Fitch states. The agency also notes in the report that restructuring Europe's current natural gas infrastructure to make it less dependent on a few sources would cost close to 200 billion euros. Analysts thus do not see that as a likely outcome. And though the International Energy Agency places the continent's natural gas in shale reserves at approximately 13 trillion cubic meters, public sentiment and governmental regulations are both against fracking. Supply troubles Europe does produce some of its own natural gas, but those sources don't come close to breaking the continent's dependence on Russian gas. Exports from Norway are expected to recede by the early 2020s, according to The Wall Street Journal, and although the Netherlands and the UK provide some natural gas to the rest of Europe, neither produces enough to help the continent achieve energy independence from Russia. Some have looked to the US as an alternate supplier given the natural gas boom in that country, but export restrictions and the high associated costs even without those restrictions mean that US gas is not a likely solution either. Meanwhile, sanctions on Russia have prompted analysts and investors to fear the country may block some or all of its natural gas exports to Europe, threatening a serious supply shortage. That's worrisome as Fitch's report shows that Europe will not be able to replace Russian natural gas should the ex-Soviet nation decide to cut Europe off.