Climate Change Overview Climate Change Overview

Rosina Bierbaum, Dean and ProfessorRosina Bierbaum, Dean and Professor

The Investor Forum on Climate Risk The Investor Forum on Climate Risk

December 7, 2006December 7, 2006

OUTLINE OF THE TALKOUTLINE OF THE TALK

Climate change is a “matter of Climate change is a “matter of degrees”degrees”

The state of scienceThe state of science Future impacts on the US Future impacts on the US Impacts already documented in Impacts already documented in

AssessmentsAssessments New and worrisome scienceNew and worrisome science The size of the energy challengeThe size of the energy challenge Pursuit of solutionsPursuit of solutions

Climate Change: it’s a matter of degrees...

Human-induced radiative forcing will greatly exceed natural and pre-21st century increments

World Primary Energy Supply by Source, 1850-1997

T changes for 2x CO2The two globes summarize computer simulations to compare the warming expected under a doubling of CO2 from the pre-industrial level with the warming expected from a quadrupling.

Note that N hemisphere mid-continent average warming in the 4xCO2 world is 15-25°F!

This is a roasted world.

A matter of degrees...

Linkage Between Climate and Air Quality

Noxious Weeds

Alliaria petolata(Garlic Mustard)

Pueraria lobata (Kudzu)Lythrum salicaria L.

(Purple Loosestrife)

A matter of degrees...

India’s worst drought for 20 years left people struggling to find water.

2003. Nature 423:673

•IPCC 1990: The observed increase [in temperatures] could be largely due to natural variability; alternatively this variability andother man-made factors could have offset a still larger man-made greenhouse warming.

•IPCC 1995: The balance of evidence suggests a discernible human influence on global climate.

•IPCC 2001: There is new and stronger evidence that most of the warming observed over the last 50 years is due to human activities.

Increasing Confidence in the Science

Computer models of climate match observations only if natural forcings (sun, volcanoes) and human ones (GHG, particulates) are included. The human forcings are responsible for most of the rapid warming 1970-2000.

IPCC, 2001

Variations of the Earth’s Surface Temperature for:

IPCC (2001) scenarios to 2100

1000 years of Earth temperature history…and 100 years of projection

Jacoby, MIT

An Interesting Way to Present Predicted T Probability Distributions

Jacoby, MIT

U.S.

WorldAverage

NAST, 2000

Health ImpactsHealth ImpactsWeather-related mortality/heat stressInfectious diseasesAir quality-induced respiratory effects

Agriculture ImpactsAgriculture ImpactsCrop yields and commodity pricesIrrigation demandsPests and weed

Water Resource ImpactsWater Resource ImpactsChanges in water supply and timingWater qualityIncreased competition for water

Coastal Area ImpactsCoastal Area Impacts Erosion of beachesInundation of coastal wetlandsCosts to defend coastal communities

Forest ImpactsForest ImpactsChange in forest compositionShift geographic range of forestsForest health and productivity

Ecosystem ImpactsEcosystem ImpactsShifts in ecological zonesLoss of habitat and speciesCoral reefs threatened

Climate change will have a range of impactsClimate change will have a range of impacts

Climate Changes

Sea Level Rise

Temperature

Precipitation

Adapted from EPAAdapted from EPA

Changing Forest Types

California:Increased winter runoff, reduced spring and summer streamflowDecrease in water supply and reliabilityin Central Valley Basin.

Examples of Regional Water Impacts

Chesapeake Bay:Sea level rise will inundate most existing wetlands.

Florida:Wetlands at riskBiscayne aquifer becomes salty; loss of shrimp, crabs, oysters, and other species

Louisiana:Sea level rise of over 4 feet by 21004,000 sq mi of wetlands at riskIncreased vulnerability of coastal drainage and sewage systems

Great Plains:Pressure for more irrigationSurface runoff and erosion of pesticides and fertilizers may increase

Colorado River Basin:Decreased runoff will exacerbatesalinity problemsShift in seasonality of runoff.Water deliveries may be dramatically affected

San Francisco Bay:With sea level rise, flooding ofDelta islands and marshes. Increased bay salinity and inland migration of saltwater

Great Lakes:Avg. lake levels could fall by 2-8 feetHigher water temps could change thermal structureIncreased dredging of ports could suspend toxic sediments

Source: EPA, 1989; EPA, 1995

Wastewater systems that combine storm drains, sewage, and industrial waste are still used in about 950 communities, mostly in the Northeast and Great Lakes regions.

NAST, 2000

Predicted ocean Predicted ocean warming will alter warming will alter suitable habitats.suitable habitats.

Temperature based Temperature based on Canadian on Canadian Climate Centre Climate Centre model.model.

Blue: current rangeBlue: current range

Red: 2090 range.Red: 2090 range.

Warming Effects on Sockeye SalmonWarming Effects on Sockeye Salmon

December

July

(Welch 1998)(Welch 1998)

Examples of Seasonal Climate Shifts

UCS, 2003

The one degree average temperature increase over the last 100 years has not occurred evenly across the globe

Rainfall has increased 8% over the US in the last 100 years

Linear trends in the date of the last measurable snow on the ground. Dark areas indicate regions where these trends are statistically significant at the 0.05 level.

Mountain snowpack is declining

Source: P. Mote, U. of Washington

OSTP, 1998

Changing Forest Pathogen Distributions

Impacts of Climate Change

Observed impacts of temperature-related regional climate change in the 20 th century

Rosenzweig, 25 Oct 2000

Observation period longer than 20 years

Studies using remote sensing

Emerging worries-- Since the National Assessment (2000) and the IPCC Report (2001)

• Rapid ice melt (Greenland and the Arctic)

• Mortality from heat-waves & disease

• increased intensity of major storms

• increased frequency & intensity of droughts

• increased frequency of great floods

• change in species ranges & behavior

• increased frequency & extent of wildfires

• Increased cost of weather-related disasters

                           

NASA photograph

Extent of Arctic summer ice in 1979 (top satellite image) and in

2003 (lower satellite image).

Shrinking Polar Ice

Greenland ice Melting 1992, 2002, and 2005

1992 2002 2005

Source: ACIA, 2004 and CIRES, 2005

In 1992 scientists measured this amount of melting in Greenland as indicated by red areas on the map

Ten years later, in 2002, the melting was much worse

And in 2005, it accelerated dramatically yet again

Greenland & Antarctic

• IPCC 2001 “central estimate” of ~0.5 meter further sea-level rise by 2100 now looks like an underestimate…maybe a big underestimate.

• All the ice on Greenland ≈ 7 m increase in sea level; ice in WAIS ≈ 5 m.

Emerging worries (continued)

• deadly heat-waves

“[P]resent-day heat waves over Europe and North America coincide with a specific atmospheric circulation pattern that is intensified by ongoing increases in greenhouse gases, indicating that it will produce more severe heat waves in those regions in the future.” (Science 8/06/04)

The Human Toll of Heat Waves: Selected Examples from Europe in August 2003

Country Number of Fatalities

France 14,802

Germany 7,000

Spain 4,230

Italy 4,175

UK 2,045

Netherlands 1,400

Portugal 1,316

Belgium 150

TOTAL 35,118

Compiled by Janet Larsen, Earth Policy Institute, October 2003.

Compiled by Janet Larsen, Earth Policy Institute, October 2003.

Extreme heat waves in Europe are already 2X more frequent due to global warming, with much more to come

Black lines are observed temps, smoothed & unsmoothed; red, blue, & green lines are Hadley Centre simulations w natural & anthropogenic forcing; yellow is natural only.

Asterisk and inset show 2003 heat wave that killed 35,000.

Stott et al., Nature 432: 610-613 (2004)

Emerging worries (continued)

• increased frequency & intensity of droughts

The amount of land suffering from severe drought has more than doubled in the last 30 years. Almost half of the increase is due to rising temperatures rather than decreases in rainfall or snowfall. (Journal of Hydrometeorology, 12/04)

• increased frequency of great floods

“The frequency of great floods increased substantially during the 20th century. The recent emergence of a statistically significant trend in the risk of great floods is consistent with results from the climate model, and the model suggests that the trend will continue.” (Nature, 01/31/02)

Emerging worries (continued)

• increased intensity of major storms

Current hurricane potential intensity theories, applied to the climate-model environments, yield an average increase of intensity of 8% to 16% for the high-CO2 environments. (Journal of Climate, 9/15/04)

The results suggest that future warming may lead to an upward trend in tropical cyclone destructive potential. (Nature, 8/4/05)

The arguments associating the increase in hurricane intensity with increasing sea surface temperature shows positive trends in both global tropical sea surface temperature and the number of category 4 and 5 hurricanes. (ScienceExpress, 3/16/06)

A gigantic, dangerous storm, Hurricane Katrina takes aim at New Orleans and the Mississippi coast. Photo: NASA

Global warming is warming the oceans. Hurricanes are powered by warm seas.

Sea Surface Temperature TrendsThe Gulf and Caribbean waters are warm and getting warmer: heat supports development of major hurricanes

Peter Webster, Georgia Tech, 2006

North Atlantic Ocean

0

2

4

6

8

10

12

14

1850 1870 1890 1910 1930 1950 1970 1990 2010

Nu

mb

er o

f S

torm

s

Named Storms Hurricanes Cat. 4&5

Since 1995, there has been ~50% greater activity than the previous peak period ca. 1950

Peter Webster, Georgia Tech, 2006

Emerging worries (continued)

• increased frequency & extent of wildfires

Wildfires have been increasing on all continents – particularly sharply in North America – and this trend is predicted to increase under even moderate further increases in global Tavg. (Millennium Ecosystem Assessment, 2005, and

Conservation Biology, 08/04).

• impacts on species ranges & behavior

A clear pattern emerges of temporal and spatial sign switches in biotic trends uniquely predicted as responses to climate change. With 279 species (84% of those studied) showing predicted sign switches, this diagnostic indicator increases confidence in a climate-change fingerprint. (Nature, 01/02/03)

Westerling et al., SCIENCE, 18 August 2006

Correlation of wildfire increases with temperature is clear

Running, Science, 18 August 2006

This works in part through soil moisture

Losses from Global Weather Catastrophes 1980-2005

Source: PEW, November, 2006

Renewables = 4 wedges

Efficiency= 4 wedges

Kelly Sims-Gallagher, Harvard, 2006

Changing Landscape

• Sense of the Senate Resolution(to be followed by real legislation?)

• Pressure coming from– Cities– States– Mainstream corporate

America– Investment– International– Drumbeat of science– New voices: Evangelicals– The election?

US Mayor’s Climate Protection Agreement

Source: City of Seattle, 2006

Completed Climate Action Plans

Climate Action Plans

Pew Center, Global Climate Change, 2006

Renewable Portfolio Standards

ME: 30% by 2000

HI : 20% by 2020

I A: 105 MW

AZ: 15% by 2025

CO: 10% by 2015

NM: 10% by 2011

TX: 10,000 MW by 2025

CA: 20% by 2017

NV: 20% by 2015

MT: 15% by 2015

MN: Xcel 1125 MW by 2010

WI : 10% by 2015

NY: 25% by 2013

MA: 4% New by 2009

DC: 11% by 2022

NJ : 20% by 2020CT: 10% by 2010

MD: 7% by 2008

RI : 16% by 2009

PA: 18% by 2020

Renewable Portfolio Standards

ME: 30% by 2000

HI : 20% by 2020

I A: 105 MW

AZ: 15% by 2025

CO: 10% by 2015

NM: 10% by 2011

TX: 10,000 MW by 2025

CA: 20% by 2017

NV: 20% by 2015

MT: 15% by 2015

MN: Xcel 1125 MW by 2010

WI : 10% by 2015

NY: 25% by 2013

MA: 4% New by 2009

DC: 11% by 2022

NJ : 20% by 2020CT: 10% by 2010

MD: 7% by 2008

RI : 16% by 2009

PA: 18% by 2020

VT: equal to load growth 2005 - 2012

ME: 30% by 2000

HI : 20% by 2020

I A: 105 MW

AZ: 15% by 2025

CO: 10% by 2015

NM: 10% by 2011

TX: 10,000 MW by 2025

CA: 20% by 2010

NV: 20% by 2015

MT: 15% by 2015

MN: Xcel 1125 MW by 2010

WI : 10% by 2015

NY: 25% by 2013

MA: 4% New by 2009

DC: 11% by 2022

NJ : 20% by 2020CT: 10% by 2010

MD: 7% by 2008

RI : 16% by 2009

PA: 18% by 2020

VT: equal to load growth 2005 - 2012

I L: 8% by 2013 †

DE: 10% by 2019

† I L implements its RPS through voluntary utility commitments

WA: 15% by 2020

Pew Center, Global Climate Change, 2006

GHG Reporting & Registries

Eastern Climate Registry

Registries in Development

Sequestration Board Studying Registries

Lake Michigan Air Directors

Voluntary RegistriesMandatory Reporting

Pew Center, Global Climate Change, 2006