Do you ever think what if Earth stopped spinning? Well, the probability of such an event is practically zero in a few billion years. If the Earth stopped spinning suddenly, the atmosphere would still be in motion with the Earth’s original 1700km per hour rotation speed at the equator. All of the land masses would be scoured clean of anything not attached to bedrock. This means rocks, topsoil, trees, buildings, your pet dog, and so on, would be swept away into the atmosphere.
If This Happens Slowly:
If the process happens slowly then the first thing we will observe is that the duration of day and night will increase gradually. And, like the poles, every region would still experience different seasons, but the temperature swings from season to season would be much greater for areas along the equator. An equatorial region would spend infernally hot months very close to the sun, while that area’s global counterpart would spend dark, frigid months very far away from it. That’s trouble for the plants and animals that have adapted to the climate of a region and, consequently, for the people living there as well.
If This Happens Immediately:
Immediately everything that isn’t at the poles, will continue moving and will be flung due east at a speed of 460 m/s. You will not be flung into space because escape velocity is 11.2 Km/s. Because the atmosphere will more gradually slow down, people in airplanes will get a better chance of surviving. Astronaut in ISS may get a better chance of living but there will be no one in the ground waiting for them. People really really near the poles may be okay for some time but the moving air will create friction with stopped earth and that will be enough to cause massive fires, unparalleled erosion and damage to anything strong enough to stay put after the initial braking. The day will become 365 days long.
Humans are an adaptable species with powerful technology at their disposal, but surviving in this situation will be challenging. If our species still somehow survive from this catastrophic incident, will crops survive the extremes of this new world? If not, the entire food chain would be in danger. Perhaps we could find new crops or modify existing ones to tolerate this new environment, you never know.