But the system already exists. Any company that thinks people care about global warming can start a global-warming related activities and people would support t

But the system already exists. Any company that thinks people care about global warming can start a global-warming related activities and people would support them. Any company that wants to reduce homelessness can start doing something about that, and if people think they are doing it right, they have ways to support this company, both by direct donations and by buying more of their products or services. Why any other system is necessary?