For those that don't understand inflection points, below is a basic graph.
With any new technology you start at 0. Additional, there is a physical limit to what anything can do. (Arguing against this makes no sense and it would be physically impossible. Everything has a limit.)
So, of course, in the beginning of new research into technology, you are moving up pretty slowly up. But you start gaining steam and the increases in gains progressively are more and more for the same amount of investment ... up to a point.
Eventually the gains you receive from the same amount of investment go down. Although you are still going up, the increases are just not as much as they were before for the same investment. This is the inflection point, and where you start to approach the limit of what can be gained in total.
A real life example would be the change in the length of the days. From December 21st to March 21st, the length of the day increases a little more then it did the day before. Also, shortly after Dec. 21st, the increases are not very obvious, but since they are ever increasing, become more noticeable as you get closer to Mar. 21st. After Mar. 21st though the increases become smaller and smaller, until June 21st. Although you still notice the increases shortly after Mar. 21, the increase in the day become less noticeable as you approach June 21st even though the day is still getting longer. Of course the opposite happens after June 21st to Sept. 21 and then back to Dec. 21st.
Nearly everyone agrees that we are past the inflection of fossil fuel production. To argue against this is foolish. Many physicists also agree we have past the inflection of increases in efficiencies in wind/solar. Although not nearly as many people are following this, arguing against this, maybe not foolish yet, but not advisable.