The Climate Web organizes a huge amount of information about carbon offsets, including approximately 100 places individuals and/or companies can purchase carbon offsets.
For your convenience we’ve listed some of those offset providers here. The list is not intended to endorse any given provider.
Blue Ventures Carbon Offset
COTAP.org - Carbon Offsets To Alleviate Poverty
Forest Carbon Works • Carbon Stewardship for Every Forest
Prima Klima - CO2-neutral
Natural Capital Partners (also Carbon Neutral)
South Pole Group
Reforest the Tropics
We Are Neutral
TIST - The International Small Group Tree Planting Program
The Climate Trust