Golmud Railway: There is a mobile flag on a train, that drives (slowly) to the current owners base. There are also somewhat hidden explosives scattered about the map. They can be triggered by a computer nearby. The explosions leave big holes, providing some cover.
Hainan Resort: There are oil puddles which can be set aflame, producing a smokescreen for cover. You can also destroy the 2 wings of the hotel. Destroy the first two ground floors on either the left or right side to demolish the left or right side of the building.
Zavod 311: You can destroy the chimney of the factory via a terminal within the factory. The terminal starts a timer (3 minutes, I think).
Operation Locker: Many locker doors can be closed, potentially hindering enemy movement. The watchtower in the middle of the map can also be destroyed.
Dawnbreaker: There are 2 gas pipeline stations, which you can activate. Once activated, the main streets cracks open and the bridge collapses.
Lancang Dam: Shoot at the damn (RPG, Tank) and it starts to crumble, which causes debris to fly around the map. Electricity also fails, which causes the buildings to go dark.
Paracel Storm: The map starts sunny and calm, but a storm is coming. Waves start to get higher and flying gets more difficult. There is a ship that crashed into a wind turbine. Once the storm hits, there are cracks that appear in the turbine base. You need to shoot at that, to break the ship free. The ship then floats to the flagpoint C (the insel), causing huge destruction to it.
Rogue Transmission: You can destroy the antenna by shooting at the 10 supporting steel ropes.