There's a pretty solid factual case for quantifiable damage here: floods in Louisiana, Texas, India, West Virginia and France and fires in California, Portugal and Canada. There's also decreased crop yield due to droughts and decreased fish yield due to ocean acidification. This is non-zero.
Almost all of those cases can have explanations that are not global warming related.
For example, in Canada those fires were huge because of too-efficient fire suppression methods. Not enough controlled fires were done in that area and Fort Mcmurray expanded beyond its Fire Protection zone.
Not every weather-related catastrophe is caused by global warming, that just harms the credibiltiy of that argument
