There are a few things that you can do to make your blog sustainable.
1) Use recycled content. Preferably content that has been recycled from other blogs or articles.
This will help reduce the amount of energy that is needed to produce the blog.
2) Use green technology whenever possible. This includes using programs like WordPress that allow you to use green technology such as renewable energy sources and water conservation techniques.
3) Make your blog interactive. This means that you should offer readers the ability to join in on the conversation and participate in polls, discussion boards, and other interactive features.
This will help keep readers engaged and interested in your blog.