Green Your Money.

Choose green banks. Buy green shares. Invest ethically.
For example have a look at the GLS bank:
https://www.gls.de/privatkunden/

Join the divestment movement for fossil fuels. For further information see:
» gofossilfree.org/what-is-fossil-fuel-divestment/  and
» 350.org/category/topic/divestment/  

Divest gold.

Gold-mining accounts for one third of this planet’s overall mercury pollution. (Another third stems from the emissions of coal-fired power plants.) Mercury is a very potent neurotoxin and yet every living being on this planet is polluted with mercury to a greater or lesser extent due to human activity. The environmental quality standard of 20 ng/g biomass set by the EU Water Framework Directive is exceeded 3 to 5 times by all the fish in Europe from the Baltic sea to the Mediterranean Sea, all freshwater fish in between included. 

As the reason for this is air pollution, not only the fish are contaminated. They were just the first to be surveyed on a European scale in 2012. Mercury targets the brain and nervous system and is highly detrimental to it. Some research draws a connection between Alzheimer’s disease, ADHS and increased mercury levels. For further information on the Minamata Convention of 19th January 2013 see:

» www.mercuryconvention.org/Convention