23 IPCC and Leading Scientists Call for Greater Ambition
and 1.5
Degree Pathway
A group of 23 leading scientists has called for greater reductions to
avoid crossing dangerous thresholds in “cryosphere” – snow and ice – regions,
stressing the need for a 1.5 degree pathway to constrain risk. The statement is based on the findings of the
Inter-Governmental Panel on Climate Change (IPCC)’s Fifth Assessment, but takes
into account important research published since that sharpens concerns about
dynamics that might be triggered within the next few decades, especially in
West Antarctica. This includes the risk
of 4-5
meters committed or “irreversible” sea-level rise that would unfold over many
centuries, but could be impossible to halt once begun.
The scientists, 13 of them IPCC authors,
others senior and cutting-edge researchers, note, "... This can set into
motion very long-term changes that cannot be stopped or reversed, even if
temperatures later decrease. Some changes, such as committed sea-level rise
from the great polar ice sheets, cannot be reversed short of a new Ice Age.”
These potentially irreversible risks include mountain
glaciers, 80% of which can be expected to disappear at current
pledges or INDCs; sea-level rise from the ice sheets of Greenland and
Antarctica; permafrost thaw and related carbon release, which may eat one-third
to one-half of current carbon budgets at existing INDCs; Arctic summer sea ice
loss; and serious polar ocean acidification, which is occurring even faster in
these waters than in oceans at lower latitudes.
As a result of these risk-filled dynamics, as negotiations
move into their final stages the scientists urge a focus on actions that will
lead to temperatures preferably under 1.5 degrees over
pre-industrial, for the best chance of limiting these risks.
Source: email from Pam Pearson, Director, International Cryosphere Climate Initiative (ICCI)
No comments:
Post a Comment