Here's why:

* Infrared Radiation: Light with a wavelength of 100 micrometers falls within the infrared portion of the electromagnetic spectrum.

* Atmospheric Absorption: The Earth's atmosphere contains gases like water vapor, carbon dioxide, and ozone that strongly absorb infrared radiation. These gases act like a blanket, trapping heat and preventing it from escaping into space.

* "Atmospheric Window": While some infrared wavelengths are absorbed, there are "windows" where certain wavelengths can pass through. These windows are generally found in the near-infrared region (around 0.7-1.4 micrometers) and the far-infrared region (around 8-14 micrometers). The wavelength of 100 micrometers falls outside these windows.

Therefore, light with a wavelength of 100 micrometers would be absorbed by the atmosphere and wouldn't reach the Earth's surface.