Letter
Prospect of sea-level rise is terrifying
David Spratt notes that the recent National Climate Risk Assessment underestimates projected sea-level rise. It suggests a one-metre rise by the end of the century, but evidence now suggests, because of tipping points, it is likely to be two metres and possibly much more. Just looking at the last Interglacial, for instance, when temperatures were a mere 1°C above pre-industrial levels, sea levels were 5-10 metres above those of today.
The State of the Cryosphere report spells out why even 2°C warming is too high. “2°C will result in extensive, potentially rapid, irreversible sea-level rise from Earth’s ice sheets … 2°C is far too high to prevent extensive sea ice loss at both poles, with severe feedbacks to global weather and climate.” Such feedbacks include dark oceans absorbing heat rather than reflecting it back into space as ice does, causing other ice sheets such as Greenland to melt more rapidly. The report suggests between 12–20 metres sea-level rise if 2°C becomes the new constant Earth temperature.
This is terrifying. Two metres would be bad enough, but 12-20 metres? So many major cities and food-producing deltas would be underwater. So many people would be displaced with nowhere to go.
The only solution is to limit warming to 1.5°C.
— Jenny Goldie from Cooma NSW