It depends on what you mean by offset. If you're okay with carbon stored in the biosphere by trees then there are plenty of programs. If you want to put carbon back in the geosphere (since trees eventually rot or burn) sending money to climeworks is the best thing available right now. Their DAC + geologic storage approach is expensive at around $1k/ton, but highly credible.
Not okay with planting trees; they will live on the whims of politicians and are too likely to be cut down later. It would have to be in the form of permanent reforestation, and I don't think anyone can credibly promise that.
The climeworks program looks like exactly the kind of thing I'm looking for, however, so thanks for pointing that out. My CO2 emissions are on the order of 10 tons per year, going by the average per capita number, so that would be around $10,000 per year, with no tax deduction available (my marginal tax is 40%). Also, looks like their pilot plant sequesters 50 tons per year, corresponding to the output of five people.
