Transcript 20070124_Science_Cafe

Climate Change: Laying out the Problem
Science Cafe
Richard B. Rood
734-647-3530
[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
• Droughts
• Floods
• Extreme Weather
• Air Composition
– Air quality
– Aerosols
– Carbon dioxide
• Winds
• Clouds / Sunlight
What do predictions tell us?
Basic physics
of temperature
ncrease is very
simple, noncontroversial.
The prediction:
Note: There i
consistency
from many
models, man
scenarios,
that there will
be warming.
(1.5 – 5.5 C)
Also, it’s still
going up in
2100!
Projected Global Temperature Trends
2071-2100 temperatures relative to 1961-1990.
Special Report on Emissions Scenarios Storyline B2 (middle of the road warming).
IPCC ‘01
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
2006 that
ice is
melting
more
rapidly
Update:
Papers in
2005 that
hurricane
intensity
has
increased
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)
–
–
•
Human health in cities
–
–
•
Soil moisture decrease, more drought
Growing season longer
Changes in insects, disease, fire …
Ecosystem – water and air quality
–
–
–
•
Heat waves / Reduced extreme cold
Air quality worse in heat
Agriculture and forestry
–
–
–
•
Temperature rise (20th Century and predicted)
Precipitation increase (20th Century and predicted)
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
What are the pieces which we must consider?
(what are the consequences)
Security
Food
Environmental
National
RELIGION
Societal Success
Standard of Living
...???...
POLICY
“BUSINESS”
ECONOMICS
PUBLIC HEALTH
ENERGY
??????
SOCIAL JUSTICE
Belief System Values Perception Cultural Mandate
Societal Needs
information flow: research, journals, press, opinion, …
SCIENTIFIC INVESTIGATION OF CLIMATE CHANGE
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
*
megaton oil equivalent
Source: International Energy Agency 2005
*
Map Projection
Geographic
Map Description
This 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)
Millions of Tons of CO2 Emitted
0
200000
400000
600000
800000
1000000
1200000
1400000
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
Top 20 Emitting Nations, 2000
1600000
1800000
Source: IEA, Key World Energy Data 2005
Kuwait
Un it ed St at es
Aust r alia
Saudi Ar abia
Sin gapor e
Can ada
I r elan d
Nor way
Libya
I sr ael
Fin lan d
Russia
The Result of Global Inequality
is Gross Carbon Inequality
T aiw an
Ger man y
Un it ed Kin gdom
Japan
Rep Kor ea
POLAND
Sout h Af r ica
VENEZ UELA
M ALAYSI A
FRANCE
World Average
CO2 Emissions
Per Capita, 2000:
1.56 Tons
Wor ld Avg
SWI T Z ERLAN
SWEDEN
M EXI CO
ARGENT I NA
I RAQ
CUBA
BOT SWANA
EGYPT
CHI NA
ECUADOR
BRAZ I L
I NDONESI A
Z I M BABWE
I NDI A
PHI LI PPI NES
PAKI ST AN
Viet Nam
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
HONDURAS
Cot e D'I voir e
CONGO
Sr i Lan ka
SWAZ I LAND
NI GERI A
KENYA
BANGLADESH
SUDAN
Z AM BI A
T ANZ ANI A
Source: Boden, 2003
NI GER
M OZ AM BI QUE
LAO
Z AI RE
AFGHANI ST AN
Et hiopia
CHAD
0
1
2
3
4
5
6
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.
New Regimes of Climate Behavior?
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 AGE?
~500 ppm
CURRENT
(360 ppm)
Differences from Past (20,000 years)
 ~100 ppm CO2
 ~ 20 C polar T difference
 ~ 5 C global average T difference
ICE AGE
~200 ppm
Time gradient of CO2 changes, 2 orders of magnitude (100 times) larger.