It's a combination of factors. That could be one of them. There's also the onset of an El Nino climate pattern, the reversal of the aerosol cooling effect from changes to low sulphur shipping fuels, spiking methane emissions, some effect from the water vapour injected into the stratosphere by that underwater volcano a few years back, and we seem to be speed-running past tipping points. It's a lovely potpourri of doom we have wrought.