Climate Change: Laying out the Problem Science Cafe Richard B. Rood 734-647-3530 [email protected] January 24, 2007.

Climate Change: Laying out the ProblemScience Cafe

Richard B. Rood734-647-3530

[email protected]

January 24, 2007

Some Climate News

• National Oceanographic and Atmospheric Administration (NOAA) // World Data Center for Meteorology // National Climatic Data Center– http://www.ncdc.noaa.gov/oa/wmo/wdcamet.html

– State of the Climate– http://www.ncdc.noaa.gov/oa/climate/research/monitoring.html#state

What is Science?

• When used in the application of the scientific method– Hypothesis is a proposition that can be tested

whether or not it is valid. Formally, by experiment, often by ability to predict.

– Theory is systematically organized knowledge based on tested hypotheses and principles.

– Principles are basic truths from which hypotheses are drawn and on which theories are built.

– Facts are information that is objectively real or true.

Attributes of Science-based Knowledge

• An important attribute of knowledge derived scientifically is that it is based in observation and tested. There is also independent testing by others (like an audit). Further, new tests are posed to challenge theories, which lead to refinement and strengthening of the theory. Sometimes the theories are proven wrong – at least in part.

The motivator: Increase of CO2

(Keeling et al., 1996)

What parameters/events do we care about?

• Temperature• Water

– Precipitation– Evaporation– Humidity

• Air Composition– Air quality– Aerosols– Carbon dioxide

• Winds• Clouds / Sunlight

• Droughts• Floods

• Extreme Weather

What do predictions tell us?

Note: There isconsistency from many models, many scenarios, that there will be warming. (1.5 – 5.5 C)

Also, it’s still going up in 2100!

Basic physics of temperature increase is very simple, non-controversial.

The prediction:

Projected Global Temperature Trends

IPCC ‘01

2071-2100 temperatures relative to 1961-1990.Special Report on Emissions Scenarios Storyline B2 (middle of the road warming).

Uncertainty

• If you were to assign uncertainty– Regional, seasonal predictions are more

uncertain than latitudinal, annual predictions are more uncertain than global, time-average prediction.

Systematic Temperature Changes

• Global Temperature increase 1.5 – 4.5 C

• Poles warm faster than globe, especially the North Pole.

• Land warms faster than ocean.

• Night warms faster than day

• Spring starts earlier

• Autumn starts later

Update: 2000s have continued trend

Update: Troposphere warming is observed. Correction of satellite temperature

Water

• Water vapor in atmosphere will increase (It’s a greenhouse gas.)

• Precipitation will increase

• Evaporation will increase (It’s warmer.)

• Snow cover will be less over most continents.

• Snow could increase in Greenland and Antarctica?

Storms, Drought, Floods

• Extreme events are expected to occur more often and to be more extreme.

Update: Papers in 2005 that hurricane intensity has increased

Update: Papers in 2006 that ice is melting more rapidly

Sea level predictions

• 0.11 to 0.43 meters due to thermal expansion, warming of the ocean water

• 0.01 to 0.23 meters due to melting of continental glaciers

• Greenland: -0.02 + 0.09 meters ???• Antarctica: -0.17 + 0.02 meters ???

• These are likely to change appreciably with the new IPCC. Comes out in February.

Systematic Look

• Freeze-free periods are getting longer

• Snow cover decreasing

• Growing season longer

• Spring is earlier• CO2 annual cycle is

getting larger

• Sea ice is decreasing• Mountain glaciers are

decreasing• Mountain ecosystems

are changing• …

Regional issues identified in assessments

• Reduction in water level of the Great Lakes (1-5 feet)– Temperature rise (20th Century and predicted)– Precipitation increase (20th Century and predicted)

• Human health in cities– Heat waves / Reduced extreme cold– Air quality worse in heat

• Agriculture and forestry– Soil moisture decrease, more drought– Growing season longer– Changes in insects, disease, fire …

• Ecosystem – water and air quality– Lower stream flows, punctuated with floods– Changes in flora and fauna (land and water) due to temperature– Invasive species

• External factors from other regions– Water for western half of U.S.

• Great Recycling and Northern Development Canal (James Bay in Canada)– Water for eastern half of the U.S.– Hydroelectric facilities– Pollution from/to other regions

Ice reduced, shoreline damage decreased, less snow removal, more land, …

What do with do with this information?

• Is this information about probable climate change accurate and interpretable?– Is it robust?– How often and fast does it change?

• Is it consequential?– Are there risks if we ignore it?– Are there risks if we believe it?

• How does this information about probable climate change relate to humans and the things that humans do?

How do we get our information?

• Direct research, generation of new knowledge• Review of the primary source literature• Journalism• Editorials• Entertainment• Public Outreach from Information Holders• Popular literature• Texts, formal education• Peer-reviewed evaluations of the state of the

knowledge of the field

How do we evaluate this knowledge?

• How do we evaluate (validate?) this information?– Personal experience

• Is it hotter where I live?

– Relative to what we know and believe• How does it impact us? Does it cost something?

– In some absolute sense?• Look at past observations• Look at ability to predict• Look at quality of observations• Look at consistency of theory, robustness of hypothesis• Attribution of change, cause and effect

This is where we will spend most of the first group of lectures

SCIENTIFIC INVESTIGATION OF CLIMATE CHANGE

What are the pieces which we must consider?(what are the consequences)

Belief System Values Perception Cultural Mandate Societal Needs

information flow: research, journals, press, opinion, …

SecurityFood

EnvironmentalNational

Societal SuccessStandard of Living

...???...

ECONOMICSPOLICY

“BUSINESS” PUBLIC HEALTH SOCIAL JUSTICE

ENERGYRELIGION ??????

Energy

• The climate change problem and energy policy are correlated, currently, they are completely intertwined.

• By most standards, energy use is directly related to societal success.

• Hence virtually all elements of society are stakeholders.

World primary energy supply in 1973 and 2003

Source: International Energy Agency 2005megaton oil equivalent

Map ProjectionGeographic

Map DescriptionThis map illustrates historic cumulative carbon emissions from 1950 - 1999 (as a percentage of global output) at a country-level . As indicated on the map, areas with highest cumulative emissions are predominantly found in "northern" richer nations such as the U.S. (at 27%) and the EU (at 18%). Alternatively, lowest carbon emissions are found in economically challenged

Total Carbon Dioxide Emissions from Fossil Fuel Use, 2000(Source: Boden, 2003)

0 200000 400000 600000 800000 1000000 1200000 1400000 1600000 1800000

United States

China

Russia

Japan

India

Germany

United Kingdom

Canada

Italy

Rep Korea

Mexico

Saudi Arabia

France

Australia

Ukraine

South Africa

Iran

Brazil

Poland

Spain

Millions of Tons of CO2 Emitted

Top 20 Emitting Nations, 2000

Source: IEA, Key World Energy Data 2005

0 1 2 3 4 5 6

Kuwait

United States

Australia

Saudi Arabia

Singapore

Canada

I reland

Norway

Libya

I srael

Finland

Russia

Taiwan

Germany

United Kingdom

J apan

Rep Korea

POLAND

South Af rica

VENEZUELA

MALAYSI A

FRANCE

World Avg

SWI TZERLAN

SWEDEN

MEXI CO

ARGENT I NA

I RAQ

CUBA

BOTSWANA

EGYPT

CHI NA

ECUADOR

BRAZI L

I NDONESI A

ZI MBABWE

I NDI A

PHI LI PP I NES

PAKI STAN

Viet Nam

HONDURAS

Cote D'I voire

CONGO

Sri Lanka

SWAZI LAND

NI GERI A

KENYA

BANGLADESH

SUDAN

ZAMBI A

TANZANI A

NI GER

MOZAMBI QUE

LAO

ZAI RE

AFGHANI STAN

Ethiopia

CHAD

Per Capi ta CO2 Emissions, 2000, Selected Nations

World AverageCO2 Emissions

Per Capita, 2000: 1.56 Tons

Source: Boden, 2003

The Result of Global Inequality is Gross Carbon Inequality

Rich countries emit around 2.5-6 metric tons carbon annually per person,

while the middle income nations are around 0.6 mT

and the poorest around 0.02 mT

POLICY

Science, Mitigation, Adaptation Framework

Some definitions

• Mitigation: The notion of limiting or controlling emissions of greenhouse gases so that the total accumulation is limited.

• Adaptation: The notion of making changes in the way we do things to adapt to changes in climate.

• Resilience: The ability to adapt.• Geo-engineering: The notion that we can

manage the balance of total energy of the atmosphere, ocean, ice, and land to yield a stable climate in the presence of changing greenhouse gases.

Global cooling?

Why do we think that our predictions today are more robust than these predictions from the 1970s?

Let’s look at just the last 1000 years

Surface temperature and CO2 data from the past 1000 years. Temperature is a northern hemisphere average. Temperature from several types of measurements are consistent in temporal behavior.

Medieval warm period

“Little ice age”

Temperature starts to follow CO2 as CO2 increases beyond approximately 300 ppm, the value seen in the previous graph as the upper range of variability in the past 350,000 years.

What do we know from model experiments and evaluation (validation) with observations

• With consideration of solar variability and volcanic activity, the variability in the temperature record prior to 1800 can be approximated.

• After 1800 need to consider the impact of man– Deforestation of North America– Fossil fuel emission– Change from coal to oil economy– Clean air act?

• Only with consideration of CO2, increase in the greenhouse effect, can the temperature increase of the last 100 years be modeled.

We will revisit this in more detail after we learn about models.

Consideration of the past record

• Recorded human history has taken place in a period of relatively warm climate.

• Since the last ice age there have been warm and cold periods where the global average temperature varies by approximately 0.5 degrees F.

• These changes have been accompanied by discernable impact on human activities.

• In the past 100 years we have seen an increase of #### degrees.– Do you feel that there has been impact on humans?

• In the next 100 years we expect to see ~ 3.0 – 10.0 rise in global average temperature.

• It is reasonable to expect impact on human activities.

Behavior o

f water; P

hase ch

ange

Differences for the Future (100-200 years) ~100 ppm CO2 (Already)

> 200-300 ppm CO2 certain ~ 8-20 C polar T difference ~ 2-6 C global average T difference

New Regimes of Climate Behavior?

ICE AGE~200 ppm

CURRENT(360 ppm)

NEW AGE?~500 ppm

Differences from Past (20,000 years) ~100 ppm CO2

~ 20 C polar T difference ~ 5 C global average T difference

Time gradient of CO2 changes, 2 orders of magnitude (100 times) larger.