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Europe, Japan, Canada have ratified; US has withdrawn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

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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