Environmental Engineering Reference
In-Depth Information
• 200-400% increases per degree in wildfire area burned in several
western North American regions for 1-2°C
• Increased coral bleaching and net erosion of coral reefs, due to
warming and changes in ocean acidity (pH) for carbon dioxide
levels corresponding to about 1.5-3°C of global warming.
• Sea level rise in the range of 0.5 to 1.0 m in 2100 (reached in a
scenario corresponding to about 3±1°C of global warming) and an
associated increase in the number of people at risk from coastal
flooding by 5-200 million
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as well as global wetland and dryland
losses of more than 250,000 square kilometers. {4.1, 4.2, 4.5, 4.6,
4.7, 4.8, 4.9, 5.1, 5.2, 5.3, 5.4}
Many important impacts of climate change are difficult to quantify for a
given change in global mean temperature, but the risk of adverse impacts
is likely to increase with global mean temperature change.
For some impacts, this difficulty arises because temperature is a primary,
but not necessarily the only, driver of change. Quantification can also be dif-
ficult due to uncertainty in observing and modeling the response of a given
system to temperature changes or other climate and non-climate factors, and
additional complexity due to the influence of multiple environmental and
other anthropogenic factors. It is clear from many scientific studies docu-
menting projected impacts across numerous sectors and regions, however,
that a number of impacts do scale approximately with global temperature.
Hence, these are expected to intensify in response to a greater temperature
change. An illustrative set of temperature-dependent impacts are summa-
rized in Figure S.6. These include shifts in terrestrial and marine species
ranges and abundances (including die-off in some cases), increased risk of
heat-related human health impacts, loss of infrastructure in coastal regions
(due to sea level rise) and the Arctic (due to sea level rise, retreat of sea
ice and associated coastal erosion, and permafrost loss). This summary of
temperature-related impacts is intended to be indicative rather than com-
prehensive. Figure S.6 does not include all possible temperature-sensitive
impacts, such as projected extinctions due to climate change and increased
risks to national security. {4.7, 4.9, 5.5, 5.6, 5.7, 5.8}
Uncertainty in the cumulative carbon or stabilized carbon dioxide concen-
tration that corresponds to a given temperature target is large. It follows
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With the range depending mainly on uncertainty in adaptation measures undertaken.
