Members of the Powering Past Coal Alliance committed to achieving the phase out in a "sustainable and economically-inclusive way", while also agreeing to a moratorium on any new traditional coal power stations without operational carbon capture and storage, plus supporting clean power through their policies.
The alliance said it hoped to have enticed in 50 members by the time the UN meet at COP24 in Poland next year.
Green activists will be rejoicing at the news, but, while the likes of the UK, France, Canada, Mexico and Austria signed up, the US, China and India were notable absentees.
China and India, in particular, are scaling back their consumption of ‘dirty' coal for power, but still require high-quality thermal coal to power their economic ambitions for the foreseeable future. Many countries in Southeast Asia will also require coal power for years to come in order to continue to prosper.
According to the alliance, coal-fired power plants produce almost 40% of global electricity today, "making carbon pollution from coal a leading contributor to climate change".
"The cost of generating electricity from wind and solar have plummeted, with the result that clean power is the low-cost option in a growing number of jurisdictions worldwide," the alliance said.
While the alliance said global investments in renewables were on the up, the majority of solutions do not offer the base-load scale ultimately required for continuous power generation. Coal, nuclear and hydro power are still the only reliable base-load sources.
The World Coal Association said the alliance should focus on commercialising technologies to make coal power greener, as opposed to coming up with overly ambitious targets.
CEO Benjamin Sporton said: "With the world set to use fossil fuels, including coal, for the foreseeable future, Canada and the UK should direct efforts to advancing carbon capture and storage technology because that's much more likely to achieve global climate objectives than unrealistic calls to eliminate coal in major emerging economies."
The WCA referenced the International Energy Agency's latest world energy outlook, which it said made clear coal would remain the single largest source of electricity generation - at 26% - through to 2040.