The United Nations has moved to ban the sun shielding program that has been suspected for a long time of being capable of blocking out just enough sunlight to save Earth from the ill effects of global warming in future generations. The use of a massive shield to stop sunlight from reaching our planet has been on the table for decades, but it may be killed if the UN’s convention of Biological Diversity votes against the measure.
The convention may be passing a measure that illegalizes blocking out the sun. And while this sounds fairly simple (who wants the sun blocked out anyway?) it may stop quite a bit of research on global warming prevention. The proposal comes due to fears that mankind will not reduce carbon emissions after the sun shield is put in place. The sun shield would only block out 2% of the sun, providing a bit of shade on Earth that would be sufficient to stifle Global Warming. At least at first.
The space sunshade program had many different proposed methods of delivery and different models of systems to be sent up at the L1 point (the point of orbit following Earth and the sun.) The Lagrange point means a propulsion system would not be necessary, and the system could follow Earth’s orbit using the power of both bodies’ gravity. Systems proposed to put there included a large cloud of small objects, a massive lens, a mesh, or a combination of all three.
The small objects would have certainly been the easiest to put up into space, but likely the most difficult to disperse if the system worked a little too well. The possibility that the program would need a better “sunset” has been explored thoroughly by those involved in studies once global warming was better under control.
There is also the possibility of a massive screen put up between Earth and the sun to block out some two percent of all the light reaching Earth. Such a screen would need to be massive, and would not have the same drawbacks as the smaller objects as it would more easily be dispersed as time wore on. The screen would also prove more effective at keeping out cosmic dust than a lens would be, ensuring the sun would not eventually cause the Earth to be blocked from more sunlight than necessary.
The other, and possibly most difficult to control possibility would involve a massive lens similar to those seen in sunglasses to be positioned between Earth and the sun to hold back the sun. Dust collection on its surface could potentially be a problem, and it would roughly have to be the same size as over half of North America if it was to be used. Simply getting it into space would no doubt be incredibly difficult.
Less ambitious plans of creating a reflective ring around Earth have also been proposed. If the United Nations were to make sun blocking technology illegal, it would undoubtedly include virtually all of these measures in favor of a more basic industrial weaning off oil in favor of more green solutions. Of course many of these solutions have yet to be developed.