CAJ - Space reflectors

Space-based reflectors

Another theoretical geoengineering proposal to reduce the amount of incoming solar radiation are space-based reflectors. These are shields positioned in space to deflect and dim sunlight back into space or to filter it. The effectiveness of the shield could vary depending on its design, material, location, amount and maintenance. Some shield materials have already been suggested like lunar glass, aluminium thread netting, metallic reflecting disks or refracting disks. It was proposed that the space-based reflectors can either be one single mirror of 1,600,000 km2 or several smaller ones. These shields would be positioned in the low Earth orbit. This idea was first suggested by Lowell Wood, a physicist at Lawrence Livermore National Laboratory. From his research he could draw the conclusion that by deflecting only 1% of sunlight, global warming could be stabilised. However, Wood considers this technique infeasible. He only suggested it as a last option, if nothing else helps to reduce global warming temperatures. In fact, launching a shield to fully combat global warming may cost a few trillion dollars. Apart from the high costs, the implementation would take over 25 years which is quite a long period of time. 

There has been a lot of debates going on about this geoengineering technique. Scientists keep on saying that further research is highly needed as the space-based reflectors technique is still not proven and is still at the theoretical or research phase. Based on the already existing research, many questions are left to answer. What are the steps for implementation? How would these reflectors be transported? Would reflectors alter the climate at a regional or at a global level? These and more questions remain still unanswered.