Earth’s climate system is replete with potential surprises, and the climate science community tends to be conservative when projecting future changes. The world also suffers from a creative deficit in imagining the human response to climate change – a deficit that fiction is well-suited to help alleviate.
One focus of my research is on sea-level change, both in the past and in the future. In his new work of climate fiction, “New York 2140,” author Kim Stanley Robinson supposes that climate scientists like me will be surprised by how quickly the world’s ice sheets will shrink and sea levels will rise. His novel explores how civilization might nonetheless muddle through to remake this reshaped world.
In Robinson’s future, the First Pulse of Antarctic and Greenland ice sheet collapse in the 2050s led to 10 feet of global sea-level rise in the course of a decade. The First Pulse and the food crisis of the 2070s served as focusing events, leading the world to take greenhouse gas reductions more seriously. Electricity generation shifted to renewables; container ships were replaced with fleets of wind-powered clippers; lighter-than-air airships replaced airplanes.
Yet these efforts were not enough to avoid a Second Pulse at the end of the 21st century, driven first by melting at the Aurora Basin in East Antarctica but then cascading around the world’s ice sheets, leading to a further 40 feet of sea-level rise.
Current science suggests the speed of sea-level rise in Robinson’s future is implausible. The United Nations’ Intergovernmental Panel on Climate Change (IPCC)’s 2013 report estimated that, under a future with high greenhouse gas emissions, global average sea level would likely rise by between about 1.5 and three feet over the course of this century. My research group’s projections generally agree with the IPCC’s assessment. But the IPCC assessed only what is “likely”; our group’s work also suggests that sea-level rise as high as about eight feet by 2100 and 18 feet by 2150 is physically plausible, though extremely unlikely.
But there’s a lot we don’t know about the behavior of ice sheets, particularly those – like the West Antarctic and parts of the East Antarctic including the Aurora Basin – that sit on ground that is below sea level. For example, warm water can attack submarine ice from beneath. If the ground underneath the ice sheet is sloping the wrong way, deepening toward the continent’s interior, the water’s advance will set up a self-sustaining cycle that exposes a growing cross-section of ice to erosion.
In addition, ice sheets can form unstable ice cliffs at their margins. A recent study that incorporated the collapse of ice cliffs found that, under a future of high emissions, it may be significantly easier to get to eight feet by 2100 and 18 feet by 2150 than previously thought. Still, even that study could not produce Robinson’s 50 feet until after 2200.