In an effort to reduce global warming, individuals and companies have been buying __________________ to fund restorative projects.

carbon credits?

http://en.wikipedia.org/wiki/Carbon_credit

In an effort to reduce global warming, individuals and companies have been buying carbon offsets to fund restorative projects.

To find the answer to this question, I used my knowledge base on environmental issues. Carbon offsets are a commonly used term that refers to a financial instrument used to invest in initiatives that counterbalance or offset carbon emissions. By purchasing these offsets, individuals and companies can indirectly mitigate the greenhouse gas emissions they generate through their own activities. These funds are then used to support projects that reduce greenhouse gases, such as reforestation efforts, renewable energy installations, or improving energy efficiency.