At http://wattsupwiththat.com/2015/10/06/recent-lunar-eclipse-reveals-a-sig… … dust from the Chile volcano, Calbuco, which erupted in April just gone, almost six months ago, has caused the moon to be a deeper shade of red than it would have been if there had been little dust in the atmosphere. The dust is still there, months later, inhibiting sunlight. This is the reason why low growth tree ring events, marked by global cooling, are generally attributed to volcanoes. Volcanoes are more common in the modern world than heavy meteor storms and the Earth has not passed through a dense region of comet dust in recent times either – but presumably the same effect would apply.
Meanwhile, another hopeful theory is that of Henrik Svensmark – clouds and solar activity. See http://notrickszone.com/#sthash.L8ocLqbs.X6bxSTMG.dpbc … the theory involves cosmic rays and the solar wind – the Chilling Stars (http://notrickszone.com/2015/10/06/eight-recent-papers-overshadow-co2-wa…