The response from fossil fuel companies to the long-awaited United Nations-backed report on climate change is exposing deep-seated divisions within the industry on how to deal with the global threat.

The publication of the scientific assessment on Monday gives a stark account of the challenges posed by rising temperatures. It calls for dramatic measures to curtail greenhouse gas emissions in order to limit warming to 1.5 degrees Celsius over the next two decades.

Most oil, gas and coal producers, as well as the power companies that burn the fuels, have remained silent. Responses from those choosing to raise their head above the parapet range from the defensive to calling on governments to take the lead on a transition to a future of cleaner energy.