This week I'm doing one which, as a Green MSP, I regard as being on my home turf.
It's been organised by Stop Climate Chaos, a broad coalition of organisations campaigning on the crucial issue of climate change. Although most Greens are pro-independence there are others who will be voting No or who remain undecided, and I'm sure this is true of climate change campaigners too.
Is there a clear reason why independence would be good or bad for Scotland's contribution to tackling climate change?
Maybe it depends more on the kind of governments we elect in future, instead of the constitutional situation.
Of course there's a lot of truth in that.
Scotland achieved a good degree of political consensus on our climate change legislation, but we have missed every single target so far.
All political parties want to say the right things but there's little commitment to doing the right things.
Without transformed policies on energy, transport, housing and the economy we will continue to see failure on climate change, whether we are independent or not.
BUT oil-dependent Scotland would be forced to face reality with more urgency than the UK.
Both governments are still utterly committed to exploiting fossil fuels; they regard them all as positive economic resources.
But in reality the world has many times more than we can ever afford to burn.
By the leading estimates, as much as 80% of reserves will have to remain unused if we are to have a chance of avoiding catastrophic climate change.
Yet much of our economy rests on the perceived value of these same reserves, as though all of them will end up being used.
This means not only that the fossil fuel industry itself is profoundly over-valued, but also that whole economies are vulnerable as a result.
This is the so-called "carbon bubble" - not just an environmental threat but a gigantic economic crash waiting to happen.
At present, the UK Government is every bit as committed to the fossil fuel industry as the SNP Government in Edinburgh.
Scotland's vast oil and gas industry creates economic vulnerability, not strength.
We urgently need to reduce our use of fossil fuels in energy terms, and reduce our economic exposure to the carbon bubble.
Independence doesn't achieve that in one step, but it allows us to begin the transition to a renewable - and economically sustainable - alternative.
We can build a greener, fairer and economically stronger Scotland.
But I'd challenge anyone to show me how the limited powers of devolution allow us even to get started.