Yes because it’s reflective of a broad Z-circulation and a strengthened NPAC High, which directly teleconnects to enhanced Indo-West Pacific Convection (which requires a strong Walker Cell, and thus augmented equatorial trade winds). Simply put. Although there are a slew of other methods to hypothetically reconstruct ENSO, I find lower frequency off-equator sub-proxies tend to offer the most insight and the best consistency.

I'm assuming you're using -PDO as a proxy for -ENSO tendency?

I assume you mean quadratic, not parabolic (the latter can refer to both quadratic or exponential functions). And yes it just barely meets a quadratic fit if you actually run the data. The modest acceleration of the SLR post-WWII is a consequence of added anthropogenic/GHG forcing, while the pre-WWII warming/SLR is naturally/internally forced. As for ENSO, reconstructions of the PDO (and SW US precipitation as well) are a good secondary proxy for low frequency ENSO tendency. Notice the previous prolonged -PDO era was during the Medieval Era, which also coincided with the last SW North American Megadrought and Cycle of General Climate Warming.

Bryan Woo stinks for whatever reason. The offense did pretty good.