Environmental Engineering Reference
In-Depth Information
TABLE S.1 Estimated Likely Ranges and Best Estimate Values for Transient and Equilibrium
Global Averaged Warming Versus Carbon Dioxide Equivalent Concentrations.
CO
2
-Equlvalent
Concentration
(ppmv)
Best Estimate
Transient
Warming (°C)
Estimated Likely
Range of Transient
Warming (°C)
Best Estimate
Equilibrium
Warming (°C)
Estimated Likely
Range of Equilibrium
Warming (°C)
350
0.5
0.4-0.7
1
0.7-1.4
450
1.1
0.9-1.5
2.2
1.4-3.0
550
1.6
1.3-2.1
3.1
2.1-4.3
650
2
1.6-2.7
3.9
2.6-5.4
1000
3
2.4-4.0
5.9
3.9-8.1
2000
4.7
3.7-6.2
9.1
6.0-12.5
of changes in potentially damaging climate-related parameters and impacts,
affecting many aspects of human society and the natural environment.
The magnitude of some near-term (next few decades and centuries)
climate changes and impacts can be estimated for specific levels of global
mean temperature change experienced, illustrating how stabilization at
different levels of greenhouse gas forcing would be expected to alter our
world (see Figure S.5). Approximate estimates of these effects, per degree C
of global warming, include:
• 5-10% changes in precipitation in a number of regions
• 3-10% increases in heavy rainfall
9
• 5-15% yield reductions of a number of crops
10
• 5-10% changes in streamflow in many river basins worldwide,
including several in the U.S.
• about 15% and 25% decreases, in the extent of annually averaged
and September Arctic sea ice, respectively
In addition, effects at particular levels of warming include:
• Increases in the number of exceptionally warm summers (i.e., 9
out of 10 boreal summers that are “exceptionally warm” in nearly
all land areas for about 3°C of global warming, and every summer
“exceptionally warm” in nearly all land areas for about 4°C, where
an “exceptionally warm” summer is defined as one that is warmer
than all but about 1 of the 20 summers in the last decades of the
20th century).
9
Heaviest 15% of daily falls
10
Unless adaptation measures not presently in hand become available
