The Effects Of Climate Change S. Elwynn Taylor Agronomist, Extension Climatologist
Economics and science of global climate disruption Philip Mote, PhD, State Climatologist Climate...
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Transcript of Economics and science of global climate disruption Philip Mote, PhD, State Climatologist Climate...
Economics and science of global climate disruption
Philip Mote, PhD, State Climatologist
Climate Impacts Group
Center for Science in the Earth System
Joint Institute for the Atmosphere and Oceans
University of Washington
Frameworks
Science: complex problem, worrisome uncertainties
Economics: cost-benefit analysisFossil fuel industry: action is a threatPolitics: long-term problems are losersEnvironmentalists: huge problem, but must
resort to scare tactics to motivate
Facts beyond dispute
Certain “greenhouse” gases warm the Earth (H2O, CO2, CH4, N2O,…)
Human activities have increased the concentrations of the major greenhouse gases
There is considerable evidence that Earth has warmed in the last 100 years
Spinning the impacts
Climate change will be all good plants grow better with more CO2
cold-related deaths will decrease
Climate change will be all bad all kinds of extreme weather are increasing Antarctic ice sheet could slide into the ocean
The facts: climate change will be bad for some, good for others. On balance: more bad, with no way to transfer benefits from gainers to losers
Estimating costs and benefits
Costs of reducing greenhouse gas emissions How fast? How far? How intelligently?
Costs of damage from climate disruption Which metrics? What assumptions about climate disruption?
Troublesome aspects: discount rate externalities low-probability high-risk outcomes
Provisions of Kyoto ProtocolBinding emissions targets for developed nations
European Union - 8% below 1990 emissions U.S.- 7% ” Japan - 6% ”
Emissions targets to be reached over a 5 year “commitment period” (average over 2008-2012)
Six major greenhouse gases included Carbon “sequestration” (e.g., forests) and emissions
trading agreed to in principle
Europe, Japan, Canada have ratified; US has withdrawn
Costs of reducing greenhouse gas emissions
Which ones matter?Where do they come from?How much would it cost to reduce them?
Enhanced greenhouse effect
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
N2O
O3
CFCsCH4
CO2
W/m2
Where do greenhouse gases come from?
CO2: burning fossil fuels (coal, oil, natural gas) to provide energy
CH4: anoxic decay in rice paddies, ruminants, landfills, swampy or boggy land
CFCs: refrigerants, propellants, cleansers; no longer produced (yay!)
Ozone (O3): urban pollutionN2O: fertilizers
Cumulative benefit of reductions
-3
-2
-1
0
1
2
3
4
5
6
7
fastslow
Greenhouse gas reduction
Buildings, industry
Transportation
Electricity generation
Cost of Implementing Kyoto Protocol
Most studies estimate costs to developed countries of implementing Kyoto at:
• 0.2 to 2% of Gross Domestic Product (GDP) without emissions trading
• 0.1 to 1% of GDP with full trading
For perspective: defense spending 3.5% GDP, entitlements 12%
Scare tactics: 4% GDP
For worst-case scenario, economic modeling assumes(1) no alternatives to fossil fuels(2) no other benefits (e.g., reduced air pollution) (3) carbon taxes will not be used to reduce other taxes
like social security(4) reductions all happen domestically In other words, “do it dumb”
For perspective: defense spending 3.5% GDP, entitlements 12%
Clean Air Act amendments (1990)
Job losses
050,000
100,000150,000200,000250,000300,000
Industrypredictions
Actual
Source: The Tradeoff Myth, by Eban Goodstein
Costs of not reducing greenhouse gas emissions
Which metrics? Market costs Lives lost Species lost (or, more broadly, disruption of ecosystem
services) Changes in distribution of costs and benefits Changes in quality of life
What assumptions about climate disruption? Rate of change Extreme events Unforeseen changes
Estimates of costs of climate change
• 0.5 to 1.5% of Gross Domestic Product for US, 2050
• ~4% Gross World Product (Nordhaus 1994)• Ecosystem services• Intergenerational equity: are discount rates
fair?• Northwest costs: 30MaF x $40/aF = $1.2b
from snowpack alone (Eban Goodstein)
Costs and benefits of stopping climate change
CostsHigher energy pricesReduced
consumptionMany lost jobs (coal,
auto, oil industries)
BenefitsReduced air pollutionAvoided damagesMany new jobs
(efficiency, renewable energy)
Science of climate change
Thousands of peer-reviewed scientific papers published Intergovernmental Panel on Climate Change (IPCC)
summarizes papers Major reports in 1990, 1996, 2001Conclusions:
“An increasing body of observations gives a collective picture of a warming world and other changes in the climate system.”
“There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.”
Facts beyond dispute
Certain “greenhouse” gases warm the Earth (H2O, CO2, CH4, N2O,…)
Human activities have increased the concentrations of the major greenhouse gases
There is considerable evidence that Earth has warmed in the last 100 years
Some evidence that Earth is warming
Global average surface temperature computed using thermometers includes correction for small urban heat island effect
Permafrost, glaciers meltingArctic ice thinningFrost-free season longer in many placesBorehole temperatures indicate warming
Global average temperature
1860 1880 1900 1920 1940 1960 1980 2000
0.8
0.4
0
-0.4
-0.8
degr
ees
Cel
sius
1928
2000
The South Cascade glacier retreated dramatically in the 20th century
Courtesy of the USGS glacier group
Trends in timing of spring snowmelt (1948-2000)
Courtesy of Mike Dettinger, Iris Stewart, Dan Cayan
+20d later–20d earlier
Some evidence that humans are responsible
Rate of warming unusual (see next slide)Hard to explain as natural (volcanoes, solar,
ocean)Warming of last 30 years consistent with basic
physics, greenhouse gas changes
The earth is warming -- abruptly
Carbon dioxide: up 32%
Methane: up 150%
Natural Climate Influence Human Climate Influence
All Climate Influences
21st century temperature change
IPCC (www.ipcc.ch)
Temperature change, 2071-2100 minus 1961-1990
1-5 meters of sea level rise in Bangladesh
John Ray Initiative, UK
Trends in timing of spring snowmelt (1948-2000)
Courtesy of Mike Dettinger, Iris Stewart, Dan Cayan
20 days later20 days earlier
Trends in April 1 snow water equivalent, 1950-2000
Northwest warming
44
45
46
47
48
49
50
51
52
53
54
1900s1920s1940s1960s1980s2000s2020s2040s
Degrees F
warmest scenarioaverage
coolest scenarioobserved
CGCM1
0
20000
40000
60000
80000
100000
120000
140000
O N D J F M A M J J A S
Flow (cfs)
base
comp 2020
comp 2040
Snake River at Ice Harbor
Conclusions
Climate disruption is already occurring, will likely accelerate
Impacts will be varied; difficult new challenges Should we put on the brakes? Can we?
Precautionary principle an ethical approach