I feel this is a representation of 2 sides of one coin or rather that thees two have similar objective but go about trying to reach it in their own very different ways, one is violent and the other is peaceful all tough they might not necessarily agree with one or the other’s way of reaching the end goal, they agree on the goal with is saving earth and the environment.
'Diversity of tactics' is really important to achieve a goal. If all you do is sign petitions, no one will take you seriously. And if all you do is violent demonstrations, you're gonna get treated as a hooligan with nothing to say.
You need dialogue to raise awareness, and protests to raise the pressure on politicians.
"Shout loudly and hit them with a big stick" -Sun Tzu