The growth in demand for energy across the globe is expected to slow in the coming decades with the increase largely driven by emerging economies, according to BP's Energy Outlook 2035.The report, published on Wednesday, estimates that global energy consumption will expand by 41% between 2012 and 2035, down from the 55% growth seen over the last 23 years.The majority of that expansion is expected to come from the emerging economies such as China and India. However, demand from the advanced economies of North America, Europe and Asia as a group is expected to "grow only very slowly and begin to decline in the later years of the forecast period".At the same time, BP estimated that shale production will ramp up in Russia and South America before the end of 2035, as they attempt to replicate the boom currently being seen in the US. This boom is expected to help the US to become energy self-sufficient by the end of the period, with the country also producing more gas and coal than it consumes.BP Chief Economist Christof Ruehl said that the wider energy market is now experiencing a "growth hump" between 2000 and 2020, entering the period where growth begins to decelerate. This slowdown is being driven by China, as well as the industrial demand for energy and coal, he said.Meanwhile, he pointed out energy efficiency is simultaneously improving across the globe: "This process shows the power of economic forces and competition. Put simply, people are finding ways to use energy more efficiently because it saves them money."BP estimates that oil will be the slowest growing of the major fossil fuels in the period to 2035 with demand growing by just 0.8% a year. Oil, gas and coal are expected to converge on market shares of around 26-27% each by 2035.As oil demand begins to slow, spare oil production capacity may reach 6m barrels a day, according to BP, the first time this has happened in decades. However, OPEC will likely lower output to monitor the impact on prices.BC