At least one Presidential candidate (Andrew Yang Democrat) has reiterated an old proposal made to the US Government in Sept. 2001 to cool the Earth with mirrors in space. The mirrors would be built on the moon, of moon rock, and delivered to the Lagrange Point 1 between the Earth and the Sun.
https://en.wikipedia.org/wiki/Space_mirror_(climate_engineering)
Mirrors built at the new moon base would be huge. Altogether 600,000 square kilometers of solar photon reflecting surface on a mesh would be required to cool the Earth one to two percent. In order to have the option of trying to build a sunscreen in space at the Lagrange Point the Congress need fund the return to the Moon program fully and quickly. Technology that is new requires some lead time.
Obviously it would be good to get some private businesses at work for the government on design coordinating with existing N.A.S.A. moon base plans.
Plainly there is no easy fix to the world problem of too many people with too much dirty technology disrespecting the ecosphere of the planet. All of the efforts to transition global economics and political economy to sustainable principles (ref. Ecological Economics 2nd ed.) need continue. The overall problem is worse than is usually reported.
N.A.S.A. image
Garrison Gibson: books and blog 