The plunge in oil prices risks undermining efforts to reduce the pollution blamed for global warming, especially projects designed to wring more from each barrel of oil, the International Energy Agency concluded in its annual assessment of markets. If the cost of crude remains near $50 a barrel until the end of the decade, cheaper conventional fuels would hold back the development of electric cars and biofuels that are helping curb carbon emissions, IEA said. It also estimated about $800 billion of efficiency improvements in cars, trucks and airplanes would be lost. The findings illustrate the complexity of the United Nations mission to secure a historic deal on reining in fossil-fuel emissions by the end of the year. While lower oil prices are helping the world recover from an economic slump, they’re also raising competitive pressures on technologies such as wind and solar power and making some projects take […]