350.org have done a bunch of stuff — as for plastic signs complaining about pollution. Yes that's annoying, (it annoys me that 350.org's website is incredibly bad for environment https://www.websitecarbon.com/website/350-org/)

If you want to make a difference, do something local. That's where the biggest shifts are happening — and you're unlikely to encounter any real arguments. People tend to only have those arguments when they have an audience, e.g. Twitter, TV