Let's discuss the Holocene Optimum, when temperatures were 1-2 degrees Celsius warmer than today for at least two thousand years. What did this sustained warmth do to "agriculture and weather patterns" at the time? Is there evidence of increased climactic variability and instability? Crop failures? Disease? Societal collapse? What about the environment? Did species suffer increased stress? Was there more habitat loss? Desertification? Did extinction rates increase among alpine, Arctic and Antarctic species? And so on.

If anyone wants to argue that a warmer climate will be generally detrimental to humanity and the biosphere, all they have to do is look to the past and demonstrate when this has been the case. It shouldn't be that hard.