My research efforts to date have focused on understanding the coupled response of the tropical Pacific to past and future climate changes, whether ENSO is going to strengthen or weaken as greenhouse gases increase, and physical mechanisms that generate decadal climate variability in the Pacific basin. My approach is to identify mechanisms that operate across hierarchies of models and relate them to physical principles. Then I focus on how these robust mechanisms operate during future and past climate changes and link their impact to changes detected in observations or proxies. Through this research I have contributed to bridge long-standing scientific controversies on the signature of climate change in the tropical Pacific during future Global Warming and the Last Glacial Maximum. I have also presented new and provoking ideas on how the atmosphere and ocean interact to generate decadal climate variability in the Pacific.