Let's be pragmatic about carbon offsets

Carbon offsets are a mechanism whereby a business or individual can pay a contribution towards a project that reduces carbon emissions by an amount equivalent to the emissions generated by a notional element of the purchaser's own behaviours and activities (eg their travel). 

There are many who take the view that carbon offsets are just like medieval indulgences, in that they only enable people to feel better about themselves while continuing to damage the environment (specifically the climate) through their behaviours.  However, that is quite a purist approach which is likely to turn some people away from the net zero transition.  A more pragmatic approach is likely to appeal to many people in the mainstream.

There are some key ways in which carbon offsets are an important part of engagement with the mainstream of society on the path to climate stability (eg Global Net Zero carbon emissions).

1.  While carbon offsets can never, in themselves and by themselves, achieve net zero, they can provide a stepping stone for people to start taking positive actions who wouldn't otherwise be in a position to reduce important elements of their carbon emissions.  For example, some carbon emissions are locked into infrastructure choices made by predecessors and past leaders/ decision-makers in (or on behalf of) their businesses or communities. 

2.  Buying good, certified carbon offsets does make a difference to global carbon emissions, compared with not purchasing them, all other things being equal.  (This is the principle of additionality that is engrained in all good carbon offset programmes).

3.  As the world gets closer to achieving net zero carbon, carbon offsets, and the market for their trading, will have to adjust, and perhaps mechanisms for net carbon removal (ie net negative carbon) rather than just offsetting (ie net carbon neutrality) will become more important. This is because the goal of global net zero carbon emissions is likely to be replaced with one for net carbon removal in order to go beyond climate stabilisation and seek a new target of climate optimisation at x degrees average global temperature above pre-industrial (with x being somewhere between 0 and the current 1.2 degrees of warming).  

Purchasers of carbon offsets should carefully consider if they could reduce their net carbon emissions in ways other than purchasing carbon offsets, as it is clearly better to reduce emissions, obviating the need for the carbon offsets to exist in the first place.  Carbon offsets should be considered  in some sense to be a 'last resort' for covering 'unavoidable emissions' (ie unavoidable by the individual or business buying them).