FEW COULD IMAGINE the ultra-conservative Vatican at the epicentre of a rebellion against rampant capitalism and its destruction of the natural world. The release tomorrow (June 17th) of what may well be the most radical papal encyclical in modern history strongly suggests we do indeed live in extraordinary times.

A leaked draft of the encyclical (or teaching letter) suggests that Pope Francis, a boxer in his youth, is coming out swinging, warning of the need for truly radical steps to arrest the "unprecedented destruction of the ecosystem". Put plainly, he warned: "destroy Creation and Creation will destroy us".

This pope is making some powerful new enemies

The pope explicitly links bare-knuckle capitalism with both ecological catastrophe and growing inequality. Given that just 67 billionaires control more than half the entire world's wealth – each individual billionaire controlling more resources than an average 100 million people – it is clear that the pope is making some powerful new enemies. These same plutocrats bankroll politics and own the media in many countries, so the backlash against Francis will be epic.

In recent months, the science-savvy pontiff, who holds a master's degree in chemistry, outraged neoliberals by dismissing 'trickle-down' economics as "a failed theory". He went on to warn that "the invisible hand of capitalism cannot be trusted". He also argued that "excessive consumerism is killing our culture, values and ethics… and the conservative ideal of individualism is undermining the common good".

Francis is the first pope from the Global South, the part of the world that has been the loser as globalised capitalism concentrated more power and wealth in fewer and fewer hands. His experience in his native Argentina, which was torn apart by economic collapses has left Francis deeply sceptical of the very capitalism pretty much every Irish politician, economist and commentator believes is essential to 'grow the economy'.

Economic growth has come with a fearsome price tag. Half of all the wild animals on Earth have disappeared since 1970, according to a major WWF study. On our current trajectory, within the next three or four decades most of what remains of the natural world will quite literally have been wiped off the face of the planet. This generation of humans is both living through and the driving force behind the greatest global mass extinction event in at least the last 50 million years.

We are facing chaos on a scale not witnessed since World War II

Meanwhile, despite the best efforts of the deniers to claim otherwise, climate change continues gathering both pace and momentum, setting in train processes that are, at least on human timescales, essentially irreversible.

Polar scientists now calculate a minimum of five metres of sea level rise is already 'locked in' as a result of unstoppable melting events in Antarctica and Greenland. This is sufficient to redraw the map of the world, and render many of our great coastal cities uninhabitable over time. However, our current greenhouse gas (GHG) emissions pathway could, in just another decade or two, increase the amount of 'locked-in' ice melt to raise global sea levels by a staggering 20 metres over time.

While global average temperatures have already risen by almost 1C, causing sharp rises in extreme weather events across the world, climate scientists warn that our ever-increasing GHG emissions as a result of burning fossil fuels are rapidly pushing the global temperature gauge towards the +2C 'red line'. Beyond this point lies a near future of weather disasters, famines, droughts and widespread economic and social disruption on a scale not witnessed since World War II.

The ecological and climate emergency is quite literally the gravest threat human beings have ever collectively faced.

While speaking as the head of the 1.2 billion-strong Catholic church, Francis stresses that this encyclical, Laudato si ("Blessed are You") is first and foremost a moral, rather than an overtly religious message. To drive home this point, the 200-page document will tomorrow be jointly launched by a Catholic cardinal, a Christian Orthodox church leader and a climate scientist who happens to be an atheist.

The encyclical will make acutely uncomfortable reading for practising Catholics like Taoiseach Enda Kenny, who, in tandem with Environment minister, Alan Kelly, has decided – for short-term gain – to make ignoring climate change de facto government policy.

This may be the most genuinely radical document in a generation

The timing of Francis' intervention is propitious: the UN's major climate conference, dubbed COP 21, takes place in Paris in December, and the pope is taking to the road on an intensive lobbying campaign in support of a deal radical enough to avert disaster. Scientists are impressed. "The encyclical is probably going to have a bigger impact than the Paris negotiations", said Gavin Schmidt of NASA.

"The attitudes hindering the path towards a solution…go from negating the problem to indifference, to