Continuing on from the theme of the last post the main paper of the COST Action HOME has been published today in Climate of the Past. This predominantly European effort (COST is a European cooperation mechanism) looked to assess a very large suite of approaches to homogenization efforts using a number of test cases which consisted of either real data or synthetic data which had known issues to the data creators for relatively small (compared to the size of the global data holdings) case study regions. Both surface temperature and precipitation were considered. Very many candidate approaches to homogenization were considered and assessed in a consistent manner allowing robust conclusions about the relative merits and strengths and weaknesses of different approaches.
The challenge for the surface temperature initiative is to build upon this by creating global rather than smaller regional benchmarks and to have a similar number of algorithms applied to the much larger global database. Only through looking at the problem in multiple different ways and consistently benchmarking these approaches we will be able to properly (adequately, robustly - take your pick) assess the true uncertainties in our knowledge of global and regional climate change and variability.
For more in-depth information on this study please see the lead author Victor Venema's blog post at http://variable-variability.blogspot.com/2012/01/new-article-benchmarking-homogenization.html and links therefrom.