Illustration: Matt Davidson. In Paris in December 2015, the world, Australia included, agreed to hold global average temperature to "well below 2 degrees above pre-industrial levels and to pursue efforts to limit the increase to 1.5 degrees", albeit the emission reduction commitments Australia tabled were laughable in comparison with our peers and with the size of the challenge. Dangerous climate change, which the Paris agreement and its forerunners seek to avoid, is happening at the 1.2-degree increase already experienced as extreme weather events, and their economic costs, escalate. A 1.6-degree increase is already locked in as the full effect of our historic emissions unfolds. Our current path commits us to a 4 to 5-degree temperature increase. This would create a totally disorganised world with a substantial reduction in population, possibly to less than one billion people from 7.5 billion today. The voluntary emission reduction commitments made in Paris, if implemented, would still result in a 3-degree increase, accelerating social chaos in many parts of the world with rising levels of deprivation, displacement and conflict.

Kepco is one of several mining companies being investigated, the NSW government said. Credit:Robert Rough It is already impossible to stay below the 1.5-degree Paris aspiration. To have a realistic chance of staying below even 2 degrees means that no new fossil-fuel projects can be built globally – coal, oil or gas – and that existing operations, particularly coal, must be rapidly replaced with low-carbon alternatives. Further, carbon-capture technologies that do not currently exist must be rapidly deployed at scale. Climate change has moved out of the twilight period of much talk and limited action. It is now turning nasty. Some regions, often the poorest, have already seen major disasters, as has Australia. How long will it take, and how much economic damage must we suffer, particularly in Queensland, before our leaders accept that events like Cyclone Debbie and the collapse of much of the Great Barrier Reef are being intensified by man-made climate change? Of that there is no doubt, nor has there been for decades. The uncertainties, regularly thrown up as reasons for inaction, relate not to the basic science but to the speed and extent of climate impact, both of which have been badly underestimated. Adani has parted ways with construction contractor Downer. Credit:AAP The most dangerous aspect is that the impact of fossil-fuel investments made today do not manifest themselves for decades to come. If we wait for catastrophe to happen, as we are doing, it will be too late to act. Time is the most important commodity; to avoid catastrophic outcomes requires emergency action to force the pace of change. Australia, along with the Asian regions to our north, is now considered to be "disaster alley"; we are already experiencing the most extreme impacts globally.

In these circumstances, opening up a major new coal province is nothing less than a crime against humanity. The Adani mine by itself will push temperatures above 2 degrees; the rest of the Galilee Basin development would ensure global temperatures went way above 3 degrees. None of the supporting political arguments, such as poverty alleviation, the inevitability of continued coal use, the superior quality of our coal, or the benefits of opening up northern Australia, have the slightest shred of credibility. Such irresponsibility is only possible if you do not accept that man-made climate change is happening, which is the real position of both goverment and opposition. Nowhere in the debate is the critical issue even raised: the existential risk of climate change. Likewise with business. At the recent Santos annual general meeting, chairman Peter Coates asserted that a 4-degree world was "sensible" to assume for planning purposes, thereby totally abrogating in one word his responsibility as a director to understand and act on the risks of climate change. Westpac's new climate policy is a step forward, but fails to accept that no new coal projects should be financed, high-quality coal or not. The noose is tightening around the necks of company directors. Personal liability for ignoring climate risk is now real. Yet politicians assume they can act with impunity. As rumours of Donald Trump withdrawing from the Paris agreement intensify, right on cue Zed Seselja and Craig Kelly insist we should do likewise, without having the slightest idea of the implications. The first priority of government, we are told, is to ensure the security of the citizens. Having got elected, this seems to be the last item on the politician's agenda, as climate change is treated as just another issue to be compromised and pork-barrelled, rather than an existential threat.

Loading We deserve better leaders. If the incumbency is not prepared to act, the community need to take matters into their own hands. Ian Dunlop was an international oil, gas and coal industry executive, chairman of the Australian Coal Association and chief executive of the Australian Institute of Company Directors. He is a member of the Club of Rome.