Do you know the cost of putting only 1kg at the Sun-Earth L1 point? To give you an idea, the cost of putting a satellite in the geosynchronous orbit is about $3

Do you know the cost of putting only 1kg at the Sun-Earth L1 point? To give you an idea, the cost of putting a satellite in the geosynchronous orbit is about $30k/kg, and the geosynchronous orbit is only 36,000 km away. But let's assume somehow miraculously we find a way to put objects at L1 as cheaply as the geosynchronous orbit. Your proposal would still cost $66 trillion. That's roughly the entire world's gdp. Do you really think this is going to be cheaper than reducing carbon emission?