Personally, I think we underestimate these changes, because we tend to project them linearly from known factors. However, physical systems typically go through phase changes at different energy levels. Phase changes tend to happen quickly, and are accelerated by positive feedback mechanisms.
For example, I see it as unlikely that we can currently model the rate of change accurately when sea level has already risen by 1m.
- This study suggests that experts’ judgments of uncertainties in projections of the ice sheet contribution to SLR have grown during the last 6 y and since publication of the AR5. This is likely a consequence of a focused effort by the glaciological community to refine process understanding and improve process representation in numerical ice sheet models. It may also be related to the observational record, which indicates continued increase in mass loss from both the AIS and GrIS during this time. This negative learning (36, 37) may appear a counter intuitive conclusion, but is not an uncommon outcome: as understanding of the complexity of a problem improves, so can uncertainty bounds grow.
Models aren't perfect, and projecting is hard, so "We find that a global total SLR exceeding 2 m by 2100 lies within the 90% uncertainty bounds for a high emission scenario," therefore we should be more alarmed, and use fewer resources on other priorities and focus on this threat. —PNAS, the journal that brought you himmicanes Models aren't perfect, and projecting is hard, so "We find that a global total SLR below 20 cm by 2100 lies within the 90% uncertainty bounds for a low emission scenario," therefore we should be less alarmed, and focus resources on other priorities. —Crackpot science deniers "Changes in population, age, income, technology, relative prices, lifestyle, regulation, governance, and many other aspects of socioeconomic development will have an impact on the supply and demand of economic goods and services that is large relative to the impact of climate change." —Intergovernmental Panel on Climate Change
Alright buddy, I think it’s time for a sea-level rise bet. :) Let’s say 2040? Does the IPCC have a current prediction? I’ll take double it. UPDATE: I'm having a difficult time nailing down a 2040 IPCC number but based on their 2013 projections, it looks like their worst case RCP8.5 scenario for 2040 is +0.19m relative to 1986-2005 (Fig. 13.11), so I'm happy to go with +0.38m at 2040. I suggest we use NASA's satellite data, where I'll be betting on =>402mm during the year 2040 (+380mm plus the +22mm level at 2000, which is very close to the 1986-2005 baseline). Continuing at the current measured rate of +3.3mm/yr, the number should be 160mm in 2040 and I'll fall woefully short.
Put me down for a 9.1 cm rise between 2019 and 2040. I'm feeling optimistic.