Proposed climate change mechanisms are many and various but generally attributable to our part of the solar system. They usually focus on temperature changes driven either by local processes such as variations in oceanic circulation, or, levels of atmospheric greenhouse gases such as carbon dioxide, or by global processes such as variations in received solar energy linked to changes in the parameters of the Earth's rotation and orbit or solar activity. However, two recent papers have suggested that we may need to look outside the Earth System and even outside our local planetary system for the possible origins of climate change, both on a decadal scale and over longer timescales of hundreds of millions of years. In each case, the galactic cosmic ray flux and its potential effects on cloud formation is considered to be the culprit.