WRONG!
I didn't say the Sun is the CAUSE of Global Warming, I said the SOURCE!
CO2 is just part of the Greenhouse trap that HOLDS the Sun's warmth, and prevents it from radiating back out into space at night. Otherwise we'd FREEZE at night! Space is average temp approx near -275 degrees!
CO2 is A SMALL part at that. 5%. The rest is water vapor about 94.5%. Can ANYTHING we do control water vapor(CLOUDS)? They're mostly from ocean evaporation.

Isn't it CURIOUS that the IPCC or the UN don't even MENTION water vapor??? THE MAJOR COMPONENT of the Greenhouse Effect?

As to: "Current technology is not ready for massive geoengineering actions." Piffle. We have RIGHT NOW ship-mounted rail-guns that can fire a 1-pound iron projectile at 3,000 ft/sec. Ball-bearings? An ounce? EASY!
If the World can build a multi-mile CERN rail-gun(that's what it IS!), we can build a mile-long one!

The only Climate ISSUE that would cause is a SLIGHT lowering of Solar radiation hitting the Earth, causing a shadow that would impact the Earth minimally, and cause an unnoticeable spot on the Sun(Do you EVER look directly at the SUN?).
It WOULD NOT cause a major impact, as we'd be trying to hopefully block 1 to 5% of heat radiation from an object a MILLION miles across! It would take YEARS to see any effect!
The shadow would not even be stationary, as the Earth rotates at 1,000/hour. L1 is stationary. The shadow would go past any point in a flash! MOSTLY near the Equator.
I'm an Engineer, I thought all that out!