The Global Warming Challenge: Can policy catch up with the science?

Michael Oppenheimer Princeton University for Washington DC Regional Conference 7 March 2009

The Greenhouse Effect Trapped Radiation Warms Earth’s Surface IPCC AR4 Ch 1

Going to the ends of Earth for evidence http://earthobservatory.nasa.gov/Study/Paleoclimatology_IceCores/

IPCC WGI AR4

The Greenhouse Problem

Fossil fuel use, driven by economic and population growth, is the major cause Total GHG emissions (billions of tons/year) IPCC AR4 SYR

Rapid growth in electric power and transport

10 9 8 total emissions ≈ 36 billion tons Electricity plants 7 CO 2 /yr 6 Industry (excl. cement) 5 Road transportation 4 Residential/services sectors 3 2 1 0 Deforestation International transport Other Refineries 1970 1980 1990 2000 Year

IPCC AR4

CO 2 Today Nature 453, p.292

Climate system primed for a big change

Physical reality outpacing responses

• Long-lived emissions, long-term commitment • Changes already underway, more to come known for some time • Demonstrated limits on our ability to adapt to extreme events • Modest warming (about 2 0 C) may imply unmanageable changes • Window to act to avoid such warming closing rapidly recent developments

CO 2 (ppm) ∆T ( 0 K) Sea level Thermal Exp.

(m) CO 2 accumulation, and consequences, very persistent: How to avoid discounting?

Solomon et al PNAS 2009

Pervasive climate change already underway: •Temperature •Sea level •Ice (glaciers) and snow •Extreme heat( ), cold( ) •Rainstorm intensity and drought ( ) •Tropical cyclones •Ocean acidity IPCC AR4 WGI SPM

Arctic Sea Ice Pack is Shrinking: Partly due to greenhouse gases, partly natural September Sea Ice Extent, 1979-2008 NSDIC

Glaciers are retreating

1979 Today Glacier length, globally IPCC AR4 WGI

Drought Intensity Increasing

IPCC AR4 WGI

Species observed to be moving up and north to avoid warming...

Comparison: 1905-1985 vs. 1986-2005 for western Europe Lenoir et al Science 2008

Photo: Leonie Haimson ...but some species have nowhere to go

Future: Emissions and global temperature projected to keep on climbing Future emissions Future Warming Warming 1900 - 1990 IPCC AR4 SYR

What makes these projections credible?

IPCC AR4 TS GEO339 Class 9 17

• What extremes of climate are likely to intensify?

More heat, less cold • More drought • More intense precipitation and flooding • Changed ecosystems, species losses • Higher sea level, maybe much higher ...with implications for food, drinking water, infrastructure, disease, ecosystems and species

But cool periods (like this winter) could occur, too Courtesy Ron Stouffer, GFDL

Over long term, killer heat waves become the norm Extreme Summer 2003: About 35,000 people in Europe succumb to extreme heat...

“normal” summer model of “normal” model of future IPCC AR4 WGI

Large changes in water for drinking, food (Year 2050) Food production tends to decline, low latitudes, 1-3 0 C Milly et al,

Nature

,

438

, 347-350, 2005.)

IPCC AR4 WGI Intensified precipitation already problematic

Ecosystems expected to shift, species disappear Up to 30% at risk of extinction, 1-3 0 C warming Role of Ocean Acidification?

Various Estimates of Upper Limit for Sea Level Rise Courtesy of Stefan Rahmstorf Until 2100: 18 – 59 cm + X (IPCC 2007) 50 – 140 cm (Rahmstorf 2007) 55 – 110 cm (“high end”, Delta Commission 2008) 80 – 200 cm (Pfeffer et al. 2008) 1.2m Grinsted et al (not shown) Until 2200: 150 – 350 cm (“high end”, Delta Commission 2008) Until 2300: 250 – 510 cm (German Advisory Council on Global Change, WBGU, 2006) IPCC range Data

Courtesy J. Broadus Predicted sea level rise could prove disastrous in some regions

US, too, needs to develop adaptation strategies. Instead, we are doing this… Courtesy Norm Psuty

Upper bound determined by behavior of ice sheets...

West Antarctica (WAIS) 5m East Antarctica 60m 7m

West Antarctic Ice Sheet Greenland Ice Sheet

...but we lack models that can reliably project

6-meter sea level rise

?

Hazard is clear but timescale and critical T are not: Would rates of rise reach ~meter/100yr Or ~meter/1000yr?

National Snow and Ice Data Center 2004

Buttressing by ice shelves may be a key factor...

But we lack a satisfactory continental ice-sheet model ( Modified from IPCC AR4 WGI ) Grounding line

Nature/Vol. 419/12 September 2002, pg. 189

Could this really happen?

We Can Also Learn from the Past Last Interglacial (LIG): Poles 3-5 0 C warmer....

(Similar to outcome of 1-4 0 C global increase in future)

... sea level was 6-9m higher...

Locations of sea level indicators for LIG (Kopp et al 2009)

...and apparently rose quickly (Kopp et al 2009)

Assessment changed: Risk more severe (Smith et al 2009)

Climate Wheel of Fortune

Courtesy MIT joint program

Key question for policy makers:

What policies and institutions, international and domestic, are needed?

1. Facilitate adaptation, already a key issue, even in developed countries

2. Legislate Domestic Cap on Emissions Pew Center for GCC 38

3. Provide other incentives and mandates to implement existing technologies

4. Decide what are “common but differentiated responsibilities”...and implement with a treaty NY Times 2 07 09 40

5. Provide incentives for R&D and commercialization of emerging technologies Carbon capture?

Nuclear?

Solar?

Statoil CCS operation, Algeria From Socolow, Sci Am 2006 Socolow, Sci. Am. July 2005

What’s there to work with:

Current Regulatory Setting • EPA/DoE/DoT regulatory action • US state–level initiatives: links abroad?

• Litigation, and threat thereof • Kyoto Protocol Part II?

• Group of 15: parallel tracks while gathering 67 votes?

• Private-sector actions

Reason for hope?

US CO 2 emissions declined as economy continued to grow 1990 1995 2000 2001 2002 2003 2004 2005 2006

Years

USEPA Net CO2 Emission Fossil Fuel Combustion Electricity Generation Transportation Industrial Residential Commercial Emissions Oil price