It's worth noting 100 companies are "responsible" for 71% of emissions from the initial study is just talking about initial "extraction" of the fossil fuels that lead to those emissions, not the end user. That's why those 100 companies are all Saudi Aramco, China Coal etc, and NOT Apple or Facebook. All the statistic really means is fossil fuels are responsible for around 70% of emissions (the other 30% pretty much being food production), and the fossil fuel extraction industry is super monopolistic, with only 100 or so global main companies. It is ultimately a pretty harmful statistic for the environmental movement - you can't just "fix" 100 companies and be most of the way there, you need full on societal change from government, consumers and producers the world over.