The Apocalypse Technocrat

Cause: An unknown interstellar fragment passes by Earth. Its immense magnetic field and energy instantly disable every electronic device worldwide, like a super EMP, and permanently alter the atmosphere, causing global temperatures to plunge by 5 to 10°C each day.

Phenomenon: Power, communications, and the internet all go down, and modern civilization collapses overnight. Gray-white clouds forever shroud the sky, and the sunlight grows faint. Heavy snow blankets every city north of latitude 30°N, and the oceans begin to freeze. This is not an instant destruction, but a slow, despairing process of suffocation.