That is certainly a relatively safe investment strategy but not immune from potential disaster, take the "can't miss" housing market in California in 2006 for example. Years ago, I invested in index funds until I investigated where I was putting my money - tobacco companies, big oil, small arms manufacturers, among others. I could no longer justify the index fund strategy. As a result, today I am probably poorer than I would have been with an index fund strategy but principles outweigh money for me. Today, you and I are enjoying free energy from the sun and breathing easier as a result - something money just can't buy. Change has to start with just one person to start a revolution.
Purely a financial exercise to consider cost opportunities. Money well invested today can buy more eco-tech tomorrow. Annualized S&P Returns (including dividend reinvestment) Last: 100 years: 10.3% 50 years: 10% 25 years: 9.7 % 10 years: 13.9%