A report published in Environmental Research Letters [1] predicts a cost between $14 trillion and $27 trillion per year for sea level rise if global mean temperature rise is not held below 2C.

Upper middle income countries are projected to experience the largest increase in annual flood costs (up to 8% GDP) with a large proportion attributed to China. High income countries have lower projected flood costs, in part due to their high present-day protection standards. Adaptation could potentially reduce sea level induced flood costs by a factor of 10.

Failing to achieve the global mean temperature targets of 1.5 °C or 2 °C will lead to greater damage and higher levels of coastal flood risk worldwide.

References

[1] https://iopscience.iop.org/article/10.1088/1748-9326/aacc76