Well done graphic. And rather conservative, actually, on feedback models where methane release (from thawing bogs, permafrost, and coastal methane hydrates) is factored in. Melting sea ice is also a large feedback factor, as infrared reflective ice surface is lost. These positive feedback factors (as well as decreased clouds) can all potentially steepen the curve, i.e. accelerate the warming.
You would think the fact that Arrhenius successfully predicted the basic trend in 1896 would lend some credibility to the field of atmospheric physics, but the deniers are pretty much a cult and not responsive to having their internet mythologies debunked.