Early estimates suggested Russia would gain substantially from ratification of the Kyoto Protocol to reduce atmospheric greenhouse gases because they would gain credit for the large amount of carbon sequestered by Siberian forests. However, recent UN estimates suggest early estimates were too high, thereby indicating Russia would be contributing less than previously thought to the drawdown of atmospheric carbon dioxide. These results provide a disincentive for Russia to sign the protocol.
Reference
Webster, P., 2004: A Eurasian tiger threatens to maul Kyoto. Science, 303, 1461-1462.