Sea levels could rise by 20 feet in areas around the globe regardless of what humans do to alleviate the problem, a new study suggests. This study came from a low-lying state area which could be most affected by rising sea levels.
University of Florida researchers wished to predict the degree to which sea levels will likely rise given global warming and other climate change. To predict the future, the researchers looked back into the past geological history of the planet. They found that when temperatures hovered near, or just above, modern day global averages, sea levels rose by around 20 feet. This process took place in climates just 1.8 to 5.4 degrees Fahrenheit warmer than our modern age. Most of this rise in sea level was driven by melting ice reservoirs in Greenland and on Antarctica, researchers found. This discovery suggests that a similar effect could take place in our modern age, researchers suggest.
"As the planet warms, the poles warm even faster, raising important questions about how ice sheets in Greenland and Antarctica will respond. While this amount of sea-level rise will not happen overnight, it is sobering to realize how sensitive the polar ice sheets are to temperatures that we are on path to reach within decades," Andrea Dutton, a geochemist with the University of Florida, said.
Carbon dioxide levels in the atmosphere are currently over 400 parts per million (ppm) and rising. Before the industrial age, concentrations of the greenhouse gas usually peaked at around 280 ppm. Levels of carbon dioxide are the highest they have been in three million years, leading researchers to look at sea level rise at that time. However, records of the era are unclear, partly due to the shift in global shorelines driven by the movement of landforms.
At a meeting in Paris at the end of 2015, nations from around the globe will come out to, potentially, adopt a legally-binding agreement to limit the rise of global temperatures by the end of the century.
"The decisions we make now about where we want to be in 2100 commit us on a pathway where we can't go back. Once these ice sheets start to melt, the changes become irreversible," Dutton said.
Sea levels are currently 7.9 inches above their mark in 1870, and continue to rise roughly 1/8 of an inch each year.
Future investigations could focus on details of how ice sheets near the poles melted during historic periods of warming. This study could help reveal details of how such changes could unfold in the coming years and decades, potentially affecting scientists and lawmakers alike.
Study of historical records to determine how sea levels could be affected by global warming and other climate change factors was detailed in the journal Science.