Introduction to Climate Change  3. Customary International Law
and Transboundary Air Pollution  The Trail Smelter dispute is
perhaps the most famous international environmental dispute. It
involved transboundary SO2 emissions emanating from a smelter
located in British Columbia just a few miles north of the U.S.
Canada border. The facts of the case were presented by the
Arbitral panel's 1941 final decision.  In 1896, a smelter was
started under American auspices near the locality known as
Trail, B.C. In 1906, the Consolidated Mining and Smelting
Company of Canada, Limited, obtained a charter of incorporation
from the Canadian authorities, and that company acquired the
smelter plant at Trail as it then existed. Since that time, the
Canadian company, without interruption, has operated the
Smelter, and from time to time has greatly added to the plant
until it has become one of the best and largest equipped
smelting plants on the American continent. In 1925 and 1927, two
stacks of the plant were erected to 409 fe