Climate policy has long been split between and .
Mitigation reduces future emissions; limits the damage already committed.
For two decades was treated as an admission of defeat.
Arguing for sea walls seemed to that emissions would not fall.
That position has quietly collapsed, for an uncomfortable reason.
The warming already in the system will play out regardless of what is emitted next year.
Adaptation spending, however, raises questions that does not.
A tonne of carbon avoided benefits everyone; a flood defence benefits whoever stands behind it.
Protection is therefore , and it tends to follow property values.
Wealthy districts acquire pumps and barriers while informal receive warnings.
Economists note a further trap: successful defences encourage building in places.
Insurance, if it is priced politically rather than , deepens that trap.
The defensible position is not a ratio between the two budgets but a sequence within each.
Adaptation should begin where lives, not assets, are most .
Mitigation should begin where a tonne is cheapest to avoid, which is rarely at home.