Activists call for a global tax on fossil fuel companies to pay the costs of damage done by global heating.

Focusing on today's damage and helping today's victims is a fundamental mistake -- the long-term damage will make today's damage look like a pin-prick.

If a tax established for the purpose of helping today's victims is heavy enough, it might have the effect of discouraging fossil fuel use. It might thus do the necessary long-term job; but we should not presume it will be heavy enough to achieve that.

If not, we had better tax the fossil fuel companies based on the damage that they will cause.