HOUSTON—Oil and gas will remain the dominant fuel source for decades to come, the industry’s top executives said on Wednesday, making their case not to be under valued as governments seek to reduce carbon emissions to address climate worries. Executives at this week’s World Petroleum Congress in Houston offered a defense of the industry’s efforts to adapt to U.N.-led climate change policies and recommendations, describing government opposition to some new projects as harming society. Any effort to bar new development “is misguided” and likely to hurt poorer nations, said OPEC Secretary General Mohammad Barkindo. Oil and gas also “can be part of the solution to tackling climate change.” Jim Teague, co-chief executive of energy pipeline operator Enterprise Products Partners, addressed proposals to reimpose a ban on U.S. oil exports. Such proposals ignore there are “people that want a better quality of life, and they don’t really give a damn about …