In Tasmania we see this with the renaming or joint naming of places with Tasmanian Aboriginal names and the debate over Australia Day versus Invasion Day.

By far the biggest shift in thinking in the past 20 years has been to move from academic revision of history to proactive steps to actually restore, to make good the alleged wrongs of the past. The idea is sometimes called restorative justice. It's an idea that has been embraced by the environmental movement and the national flashpoint is likely to be Lake Pedder, again.

For over 20 years from the 1970s through to the early 2000s Tasmania was wracked by conflict over the future of hydroelectricity water storage and then over forests.

Often the debates were so polarised that there was no grey, only black and white. Language you used put you in one camp or the other. The phrase "locking up forests" meant you were on the side of industry, the phrase "protecting the wilderness for future generations" meant you were a Greenie.

The flooding of Lake Pedder in the summer of 1971/72 was one of those polarising moments.

Even today the actual words Lake Pedder are still contested with many people arguing that it is indeed no longer Lake Pedder but rather a hydro storage dam, a water impoundment. The original Lake Pedder is under the storage dam.

These were and still are emotive conversations, bubbling away below the veneer of our civilised society.

It will be 50 years in the summer of 2021-2022 since Lake Pedder was flooded and we are now in the UN Decade of Ecological Restoration. There is a movement underway to restore the original Lake Pedder, with some seeing it as economic madness, others as remedying past errors.

So what are the views of the two camps?

There are four interconnected main arguments supporting the restoration:

The main interconnected arguments against the restoration are:

Try any of these arguments for either view in your next pub visit and see what happens!

Some of the debate will be over facts, for example the contribution of the storage area to total power generation and revenue, what actual area would be restored, the direct and indirect costs of restoration, who would bear the costs, and the future business model for the South West Wilderness area including tourism infrastructure.

But a lot will just be about values and, sadly, we can expect some vitriolic personal attacks and denigration of sanity.

Globally the restoration of flooded areas and removal of dams is a major and rapidly-growing industry most often associated with ageing infrastructure and restoring river flows and ecosystems. So there is now a lot of evidence to sieve through. Facts and alternative facts will be flowing!

Whether and how to restore Lake Pedder is a very sensible discussion to have, one where the words "right or wrong" are genuinely grey for many Tasmanians. It is in part a debate about economics but also a debate about who we are and want to be as Tasmanians. The symbolism, for or against, should not be underestimated. Quite paradoxically the intrinsic linking of the restoration with the past half-century of the Greens means many Tasmanians will see it as an unpalatable vindication of the environmental movement and go straight into 'cancel the idea' mode.

While the Baby Boomers and then Gen X dominated debates since the 1970s, it will be the attitudes and values of Gen Y and the Millennials that matter most now.

My own view is that, irrespective of past politics, if we are to believe the rosy Brand Tasmania prospectus of why people should choose to live and work here - our pristine place and the 'narrative' of our innovative people - a restored Lake Pedder will one day be on the front page.