As nearly everybody now understands, the changes that have occurred in public policy in the last few weeks are without precedent, at least since the Second World War. They tell us in the most straightforward possible way that only government finance and organisation can support the people in a national emergency.

They tell us that the extreme free market, small government model propounded by a Think Tank like the Institute of Public Affairs (IPA) doesnt work when it matters most.

They show us that independent institutions with a public purpose like the ABC and CSIRO truly are part of the bedrock of Australian society. And they remind us, as we endlessly discuss issues of public health, that good government policy just cannot be based on the perverse denial of scientific understanding.

You could be forgiven for wondering if the IPA, its world-view shredded by todays real life events, would take time out for a bit of thought. No need to do that, however: it has already been reported that its Executive Director John Roskam has seen a new opportunity.

He suggests that there is now an urgent need to scrap regulatory red tape, to prioritise jobs irrespective of other considerations.This has done, he said, what Adani couldnt do: put jobs ahead of the environment.

Its easier to come to grips with the ethical irresponsibility of this proposition if you understand that there are really two interwoven crises of the global environment. Climate change on the one hand and runaway loss and extinction of species caused by habitat destruction and disease on the other, work together to amplify the collapse of ecosystems and indeed to increase the risk of zoonotic disease for humans.

The closer the condition of an ecosystem to its intact natural condition, the lower the risk of premature release of carbon into the atmosphere. At the same time, climate change exposes ecosystems to intensified loss from drought, fire, disease and pests, resulting in the premature release of carbon into the atmosphere.

In science-based forums around the world and in the Paris Agreement on Climate Change itself it is accepted that up to one third of necessary greenhouse gas abatement can be achieved through the protection and restoration of natural systems. It is conventionally understood that all intact ecosystems, and especially forests, absorb immense amounts of carbon. Natural forests are far more carbon-dense than tree plantations, which can indeed be almost useless for the purpose.

All the States of Australia, along with much of the world if not the Commonwealth Government, now accept that the globe must reach a target of zero net emissions by 2050 if we are to limit cascading, climate change-induced catastrophes even greater than those with which we are beginning now to become familiar.

The stark choice is to increase environmental protection and healing to help the world to reduce emissions or to make that reduction much harder, perhaps impossible, by continuing present trajectories of environmental destruction. Let alone by increasing them.

Consider this: if you destroy an existing carbon-dense natural system now a mature forest or an intact wetland it is not physically possible to restore its carbon-fixing capacity before these next critical thirty years have already passed. That is to say, it is overwhelmingly more beneficial for the planet to make jobs by keeping nature intact than it is to create them by destroying and disrupting it.

The most important environmental action we can take is to preserve existing forest and woodland and the carbon they will absorb in ever greater amounts as they continue to grow. Significant benefit can also be gained by supporting and encouraging the restoration of presently degraded natural areas of all kinds, encouraging cultivation techniques that will increase the carbon content of agricultural soils and by controlling pests and disease across the board.

It is now a decade since the Abbott Government shattered the mostly bipartisan approach to nature conservation that had lasted at the Federal level from Whitlam to Howard. Abbotts hostility to nature conservation was inseparable from his climate denialism, an opportunity for a culture war. His attacks on national parks and the evisceration of the world-leading Landcare program for farmers accompanied the abolition of the Department of Climate Change, the assault upon the Clean Energy Corporation and the abolition of the carbon pricing mechanism.

We inhabit a singular and beautiful country. Isolated and geologically stable for millennia, it has evolved unique ecosystems and many species that exist nowhere else. Its soils are ancient and fragile, its weather patterns unusually variable. In consequence, its environment is especially vulnerable to damage from vegetation clearing, from European farming methods and feral invasion. Its loss of biodiversity is demonstrably serious, made worse in recent times by drought, bushfire and the sometimes scandalous mismanagement of natural resources.

At a time when expenditures on conservation in the public sector and incentives for conservation in the private sector should have been massively increased to help the nation deal with biodiversity loss and climate change, the Federal Government drastically reduced them. Most State Governments took their cue, reducing the funds necessary to maintain national parks, intensifying forest logging and increasing the clearing of native vegetation.

Much of the grotesquely destructive Abbott program, not since reversed, precisely followed a blueprint set out in published papers of the IPA. It has been calculated by the Australian Conservation Foundation that the Commonwealth diesel fuel subsidy is by now worth nine times the federal budget set aside to care for the nations land.

So if we are to be snapping back environment policy anytime soon let it not be to a time when the IPA last led government so disastrously astray. Let it be back to anytime before the Abbott budget of 2012, to a time when Australia often took nature conservation seriously and often led the world with innovations like Landcare, The National Reserve System of protected lands and Indigenous Protected Areas.

We know how to create regional jobs in their thousands through both public and private initiatives in conservation and regenerative agriculture: through funding support, market based incentives and the generation of confidence in coherent government natural resource management policy. One third of expenditure to deal with climate change could reasonably be spent on the preservation of nature.

The Murray Darling Basin Plan has its problems, the National Party the worst of them. It may be recalled however that more than a dozen years ago John Howard secured bipartisan support to commit to expenditure of $13 billion over twelve years for its implementation. An amount four of five times larger than that would be a serious down payment on a national plan to address the degradation of our land and the changes threatened to our climate.

It can no longer be said to be an unaffordable amount to spend to secure our future.

Bob Debus was Attorney General, Minister for Environment and Minister for Emergency Services in the Carr Government in New South Wales