Sea levels may rise by up to 10 feet as early as now, says James E. Hansen, the veteran climatologist-turned-campaigner and former director of the National Aeronautics and Space Administration (NASA) Goddard Institute for Space Studies.
For Hansen and his colleagues, the climate events that transpired during the late Eemian period may provide valuable insight into the effects of human-driven global warming, especially since the high temperatures then were somewhat comparable to present temperature changes.
The researchers performed simulations of the late Eemian era and tried to identify information that could help experts understand the global climate change occurring in this generation.
Today's climate change is more intense and swift compared to the previous period, the researchers believe. Nonetheless, comparing details from two different periods may spark new concepts.
The experts theorized that ice sheets exposed to ocean waters are prone to non-linear fragmentation due to the increase in ocean temperatures and that the amount of ice sheet loss can be estimated through a doubling time, indicating a rise in sea level by several meters. The doubling times of 10, 20 or 40 years may result in sea level elevations of several meters in 50, 100 or 200 years.
The researchers conducted a variety of simulations of a sudden ice sheet collapse in the Antarctic and a rise in sea levels of several meters in storm-raked seas.
The results posted in the Atmospheric Chemistry and Physics Discussions, where pre-publication papers submitted to the European Geosciences Union are contained, show that ice sheets melted and discharged when the subsurface of the ocean underwent warming.
The simulations devised by the researchers also boosted the feedback in the Southern Ocean. This delays water formation in the Antarctic; shoots up the temperature of the ocean close to that of the ice shelf grounding lines; decreases the temperature of the ocean; and enhances the sturdiness of water columns and the outer layers of ice.
The cooling of the ocean surface elevates several climatic factors, including the horizontal temperature gradient in the troposphere, resulting in more intense storms.
"Not only would it be 10 feet, but it would imply that in the next decades after that it would be even more," said Hansen. Waters from both the west and east Antarctic ice sheets are showing a display of sea level rise.
This could mean that the coastlines would get impaired. Some parts of the world may still emerge above the water surface, but Hansen said people would find it pointless to rebuild structures as the waters will keep on rising. Such disaster may affect not only those living near the coastline, but the entire population as well.
In conclusion, the researchers said that the 2-degree Celsius global warming above the preindustrial level is highly disastrous as it would lead to more ice melts. Eradicating the imbalance of energies in the planet is the key to preserve the climate.
Photo: Christine Zenino | Flickr
