If you’re someone who invests in specific companies or bonds, then you have it easy. All you need to do is add one step to your stock picking process - simply screen out companies whose revenues come primarily from fossil fuels. An easy place to start is world's largest fossil fuel suppliers.
If you'd like to go further, the next step would be to avoid investing in the companies that specialize in selling support services to the major suppliers – companies that assist in locating, extracting, refining, and delivering fossil fuels. That focus will be stated throughout the company website and written materials, and in the corporate summary information on business and financial news websites.
Putting this idea into action is pretty straightforward, but an example can’t hurt. Suppose you're an advocate of one of these stock screening ideas. After you run a screen using the rules you like, you can extract any fossil fuel companies that come up in the resulting list. That doesn't change the underlying stock picking strategy one iota. The same basic idea can be applied to any stock picking strategy.