"So MLK's peaceful approach didn't accomplish anything?"
He didn't say violent, he said angry. And MLK was certainly angry. Listen to many of his speeches!
We're talking about direct action, not necessarily bombs (they have a lot more of those than we do

).
"Should we throw bricks through the windows of Hummers?"
Something like that has crossed my mind.
But we do have to stop being tolerant of people who think it's cool to blatantly waste resources of any sort.
In the civil rights struggle, ordinary Americans were also the enemy (still are) as well as laws, law makers, businesses...
But in this case, most ordinary Americans don't get up planning to cook the planet. They get up having to get to work, cook food, and keep warm. If they can do those in ways that don't harm the planet, most would be more than happy to.
It is only heads of ff companies and the minions they bribe to do their will who are dead set on making sure that the only way people can fulfill these basic needs is by depending on burning up their fossil-death-fuels.
The people who are making the decisions that are damning us and our children and most complex life on earth to suffering and oblivion all have faces and all have addresses.