This artist’s rendering at left suggests a device that its proponents say will, one day, capture CO2 from the Earth’s atmosphere, and mitigate the growing threat of climate change.  But let’s think about this for a moment.

The concentration of CO2 in our atmosphere is fairly consistent from the planet’s surface up to about 60 miles in elevation.

Given that the radius of the Earth is ~4000 miles, and that the volume of a sphere is 4/3 πr³, this means the volume of this section of our atmosphere is 4060 4/3 πr³ – 4000 4/3 πr³, = 2.9 trillion cubic miles.

How many of these devices will be required to make a significant dent in the overall CO2 concentration, given that they need to process almost 3 trillion cubic miles of our atmosphere?  What’s the cost per each one? How will they be powered, given that our grid-mix is largely fossil fuels?  Won’t this only make matters worse?

This is a sad joke, but even sadder, it’s not the only one out there.

Whenever We See an Artist’s Rendering, Rather than a Photograph of a Working Prototype, We Need to Wonder