How many TVs to save the Earth?

The short answer:  Somewhere between two and three-point-five billion.

It is generally believed that improved "Standard of Living" somehow causes a reduction in birthrate.

It can be argued that the common Television is the most iconic marker of "Standard of Living" and is the prime conduit for the communication of cultural mores and norms.

If the number of TVs per 1000 people actually causes changes in the birthrate, it should be possible to plot that relationship and back calculate the optimum number of TVs per 1000 people.  "Optimum" of course, is related to one's goals.  Two such "optimums" are calculated.

Data of the thirty largest countries by population, the number of TVs/1000 people and their birthrate.

The charted data with no lines added

The data with something resembling confidence bands, a dashed mid-line, and a red "Replacement Birthrate line".

The vertical line on the left represents the intersection of the mid-line with the Replacement Birth and suggests that 300 TVs per 1000 people would result in the population pretty much staying where it is.

The vertical line on the right suggests that 500 TVs/1000 people that would result in no country having more than Replacement Birthrate and thereby creating a gentle glidepath in global population.