This is interesting:
Using orbital radar satellite imagery, Charlotte Skonieczny of the L'Institut Français de Recherche pour l'Exploitation de la Mer and her colleagues looked beneath today’s bone-dry, sandy desert to geological features beneath. These ancient features helped them map a river system some 320 miles long that lines up perfectly with the sediments and underwater canyon.
This started 245,000 years ago.
But don't worry. Of course there is a global warming angle:
The Sahara's climate shift was driven by subtle variations in the Earth's orbit around the sun, the researchers say. That such a drastic shift could arise from such minute variations in sunlight is "Yet another reminder," the researchers write, "in the context of the growing greenhouse gases emissions (another external forcing), of how sensitive the climate system is."
Yeah, no big research money for orbital variations, I assume.
You know what else that Sahara climate shift is a reminder of? The importance of that big hot thing up in the sky that we call the Sun on the climate of our planet.
When the energy reaching Earth from that massive ball of nuclear fusion changes, our climate changes. It's the damnedest thing.
But variations in the Earth's orbit isn't a factor that can be affected by forcing people to mindlessly sort trash into multi-colored bins. So it is only a reminder of something else that some people can pretend will affect the climate.