These findings in the IPCC AR4 WG3 have received a lot of attention in recent years during the international negotiation process. However, the background information of Table SPM. 5 (Hanaoka et al. 2006) and original literature of Box 13.7 (Den Elzen and Meinshausen 2006) did not provide detailed information on the feasibility of achieving such GHG mitigation targets and their mitigation costs in the

mid-term (around 2020–2030). Since the IPCC AR4 was published, several modeling comparison studies have been done or are ongoing, such as the Energy Modeling Forum (EMF) 22 (Clarke Selleck BV-6 et al. 2009), Adaptation and Mitigation Strategies (ADAM) (Edenhofer et al. 2010), Asia Modeling Exercise (AME), EMF 24 and so on. However, these modeling comparison studies focused mainly on long-term (up to 2100) climate stabilization scenarios. In light of that, this comparison study focuses on an

in-depth analysis of the mid-term (2020–2030) transition scenarios analyzed using a global multi-region and multi-sector model. Mitigation potentials in major GHG emitting countries by multi-regional analysis The IPCC AR4 WG3 also pointed out that mitigation GANT61 efforts over the next two to three decades will have a large impact on opportunities to achieve lower stabilization levels and

that energy efficiency plays a key role in many scenarios for most regions and timescales (see pp 15–16 of the SPM in the IPCC AR4 WG3). BIX 1294 ic50 Improved energy efficiency is one of society’s most important instruments for combating climate change in the short- to mid-term. In order to reinforce these key messages, the role of energy intensity improvement in the GHG stabilization scenarios for six different categories on Table SPM. 5 in the IPCC AR4 WG3 were analyzed in detail for the short- to mid-term by Hanaoka et al. (2009). However, most of results were aggregated on a global scale due to a lack of data availability on a national scale and only one analysis has been done on multi-regional CYTH4 scales in Category IV on Table SPM. 5. Box 13.7 in the IPCC AR4 WG3, while its original literature (Den Elzen and Meinshausen 2006) also gives information on emission levels in Annex I groups in 2020 but does not indicate any key messages on a national scale. Therefore, this comparison study focuses on more detailed regional aggregations that cover the major GHG emitting countries and regions such as USA, EU27, Russia, China, India, Japan, the whole of Asia and Annex I, by using a global model with multi-regions.