At http://phys.org/print289737797.html … stalagmites from a cave in Borneo have been used to produce a 100,000 year temperature tool, displaying warmings and coolings during the last Ice Age. These appear to correspond with the various Dansggard-Oeschger and Heinrich events and in general support ice cores (from Greenland and Antarctica). The article was published in Science Express (June 6th, 2013).
Meanwhile, the Irish Annals (medieval chronicles from monasteries) record a succession of cold dips over more than 1000 years, AD4531-1649, that are thought to tie in with volcanic events – published in Environmental Research Letters, and once again they also seem to tie in with Greenland ice cores – more or less. The assumption here is that the chemical signature in the ice cores related to volcanoes excludes the possibility of anything else impacting on the atmosphere at those times – not to say that it did, but that it is not explored. See http://phys.org/print289670133.html
This brings us around to a third link at http://phys.org/print289751479.html … where we learn that a meteor shower in October 2011 deposited a ton of dust and material on the Earth – via the atmosphere. This material has an origin in an outgassing comet, Comet Giacokini-Zinner, which apparently has a 6.6 year periodicity. Each time it comes close to the Sun it sublimates ices and ejects large numbers of particles (debris). The oldest of the threee particle formations, or meteor streams, formed a swarm that the Earth passes through each year in October – known as the Draconid meteor shower. The research is published in the Monthly Notices of the Royal Astronomical Society.