Well, then carbon offsets raise in price as it becomes more expensive to offset a given quantity of CO2. This makes various schemes relying on purchasing offset

Well, then carbon offsets raise in price as it becomes more expensive to offset a given quantity of CO2. This makes various schemes relying on purchasing offsets more and more expensive, until they become unfeasible or are spending so much that really radical advanced techniques can be developed or become realistic to implement. Economics is a powerful tool.