Does
past sea level rise portend future rise from warming?
You may have seen claims in recent weeks that historic records show a global temperature rise could give us sea levels 20 feet higher than the norm. How accurate are these claims, and why is it important that we take this issue seriously?
The reports are a result of a University of Florida
study that was recently published in the journal Science.
The
researchers, including lead author Andrea Dutton, wanted to investigate how
historically Greenland and Antarctic ice sheets have reacted to global
temperature rises and therefore get a glimpse of how current climate
change might impact our sea levels.
The international team of scientists wanted to look at evidence of peak sea levels during several different periods of history and how that affected the polar ice sheets.
They used computer models and geological
evidence to specifically identify when average temperatures were around 1 to 3
°C (1.8 to 5.4 °F) above preindustrial levels–this being the standard
level that we use to assess modern climate change.
The researchers then looked
at how high global sea levels were compared to the base rate when the ice
sheets in Greenland and the Antarctic had retreated.
They discovered that, 125,000 years ago, sea levels rose between
20-30 feet when the average global temperature was one degrees Celsius higher
than preindustrial levels.
The researchers point out that this is about the
temperature we’re currently at. A global target is to keep global temperatures
below 2 °C, something that experts warn is critical in order to prevent
the worst effects of climate change.
“This evidence leads us to conclude that the polar ice sheets are
out of equilibrium with the present climate,” Dr. Andrea Dutton is
quoted as saying.
“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.”
Read more at ENN Affiliate, Care2.
