While all oil and gas pipeline projects raise specific social, cultural, and local environmental concerns, often including issues of tribal and indigenous sovereignty, their effect on climate change is a sufficient independent basis to oppose them: The International Energy Agency said in its 2014 World Energy Outlook that to preserve even a 50% chance of keeping global average surface temperature rise below 2° Celsius (above pre-industrial), all fossil fuel infrastructure projects would have to stop by 2017 as part of an urgent transformation towards renewables. (The 2°C goal itself being highly risky to many populations, as recognized by the 2016 Paris climate agreement’s aspiration to stay below 1.5°C).
Information on major pipeline fights:
ENVIRONMENTAL JUSTICE INITIATIVE - New York Environmental Law & Justice Project - 