Hi Tom. Good post. But you've overlooked something. The climate models used for projections of future climate (the models stored in the CMIP3 and CMIP5 archives, which were used by the IPCC for their 4th and 5th Assessment Reports) cannot simulate basic ENSO processes. See Guilyardi et al. (2009): http://www.knmi.nl/publications/fulltexts/guilyardi_al_bams09.pdf And see Bellenger et al. (2012): http://www.knmi.nl/samenw/euclipse//Publications/Bellenger_etal_ENSO%20representation%20in%20climate%20models%20from%20CMIP3%20to%20CMIP5.pdf Those climate models that make long-term projections need to be able to simulate those basic processes before we need to consider what they say about how ENSO might change in the future. . Cheers.