Environmental Science:
Atmosphere, Ocean, Biosphere
• What changes are occurring in the global
environment, how do we know?
• Can we discover why these changes are taking place?
• What are the consequences?
• EPS 5 starts at the beginning—the physics,
chemistry, and biology of the atmosphere, land,
and oceans—and finishes at the threshold of the
science—society interface.
Intergovernmental
Panel on Climate
Change – IPCC
EPS 5: organization
Prof. Steven C. Wofsy Prof. Daniel J. Jacob
swofsy@seas.harvard.edu djacob@fas.harvard.edu
Science Center Room 309
1:00 – 2:30 PM Monday and Wednesday
EPS 5 explores some of the most prominent and difficult
environmental problems of the 21st century, arising from the
global imprint of people on the atmosphere, oceans, and
biosphere: climate change (human-caused and otherwise),
global changes in the chemical and biological functions of the
atmosphere and oceans, modification of major geochemical
cycles.
The course consists of lectures (3 hr/week), sections (1
hr/week), laboratory demonstrations (during the lecture
periods), and a reading/writing project conducted throughout
the term, using primary scientific articles on climate and
environment.
Note: Attendance at lectures and sections is required.
Students are requested not to use laptops or cell phones
during class.
Participation 10%
Homework
20%
Midterm Exam 15%
Final Exam
30%
Writing Project 25%
• Online Sourcebook: Material such as scientific
articles for writing assignments and secondary sources
for help with the subject matter, available on the website.
Items will be added during the term.
• Textbook: The Atmospheric Environment : Effects of
Human Activity by Michael B. McElroy
Student work in EPS 5
Students are encouraged to form study groups
and to discuss EPS 5 concepts and materials with
their fellow students.
However, all submitted work must be carried
out by the student submitting the work.
Joint submissions of a collaborative product
(problem set, written assignment, term paper),
or use by one student of material authored by
another, are not permitted.
EPS 5 Writing Project information
The EPS 5 Writing Project is different from most
course term papers in structure and purpose.
•Students prepare a term paper (6-10 pages, due at the end of
the first week of reading period) by conducting in-depth
analysis of a topic using primary sources from the scientific
literature. A structured set of assignments leads up to, and is
incorporated into, the term paper. Students will get credit for
completing and receive detailed feedback on their short
assignments, but only the comparative critical summary and term
paper will be given letter grades.
•The writing assignments build towards the term paper.
Students develop new skills for critical analysis of science/societal
questions, and new insight into the process of understanding and
analyzing primary sources in general, while preparing a paper on
a compelling scientific issue that is developing at the current time.
Topics for EPS 5 Writing Project in 2010
1. The recovery of stratospheric ozone
Stratospheric ozone declined since the 1970s, and the Antarctic
ozone "hole" appeared in 1980. The Montreal Protocol banned
the substances responsible for depleting stratospheric ozone.
How effective has this treaty been in reducing emissions and
restoring ozone?
2. Climate in the Past : Reconstructing the Temperature
Record Since the End of the Ice Age
We cannot do controlled experiments on the earth's climate system
in order to predict the future of climate. But natural events have
been imposing climate changes for millions of years. How are
past climates reconstructed, and what do we learn from these
studies? What is the substance of the controversy over
published reconstructions of temperatures over the past 1000 or
5000 years?
Paleoclimate data from Antarctic Ice Cores
The heavier temperature lines from 160,000 BP to present reflect more data points for this time
period, not necessarily greater temperature variability.
Climate and Atmospheric History of the past 420,000 years from the Vostok Ice Core, Antarctica, by Petit
J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J. Delaygue
G., Delmotte M. Kotlyakov V.M., Legrand M., Lipenkov V.M., Lorius C., Pépin L., Ritz C., Saltzman E.,
Stievenard M., Nature, 3 June 1999.
+1
-1
oC
0
Antarctic Temperature: past 1000 years
DT Law Dome
N. HEMISPHERE TEMPERATURE:
THE PAST 1000 YEARS
Climate has been warming…
Intergovernmental Panel on Climate Change (IPCC)
GLOBAL CLIMATE CHANGE SINCE 1850
Climate has been warming, and sea level rising…
Are these
changes
"natural"?
Weather statistics on the monument
at Great Blue Hill changed from the
first 100 years. For the 125-year
period from 1885-2009 the new
statistics are:
•Average Temperature: 47.5 deg
F [old value is 47.1 deg F]
•Average Precipitation: 48.58
inches [old value is 47.44 inches]
•Precipitation Annual Maximum: 71.00
inches, 1998 [old value is 65.51
inches in 1972]
•Average Seasonal Snowfall: 60.7
inches [old value is 60.1 inches]
•Average Wind Speed and Direction:
14.9 mph, W [old value is 15.4 mph,
W]
Recent trends in T
and precipitation at
the Great Blue Hill,
Milton, MA.
What processes might
influence these data?
•Land use change
•Urban energy use
•Instrumentation, station
•Global climate trends
•Changes in ocean currents
1979
The Arctic
Ocean has
been covered
by floating ice
for all human
history…
2007
…until this year!
What do these
changes mean for
climate, forests,
crops?
Sea Ice
thickness
declined
dramatically
starting in the
mid 1980s.
Rate of Ice volume change:
All Greenland:
-238 km3/yr
South Greenland: -164
North Greenland: -65
73.250 N
-238 km3/yr = 0.5 mm/yr sea level rise
Weather: what is it? Pressure, winds, buoyancy, precipitation.
Weather
latitude
climate
longitude
January
July
Seasonal changes in temperature, pressure, winds: even
though weather is very variable and climate changes appear
small in comparison, climate is critically important in
shaping life on earth.
Pressure anomaly scale (mb)
Climate/weather
Land Surface Temperature (C) Dec 2001—Feb 2002
Infrared composite/global moll
weather, or climate?
Sea Surface Temperature
SST
Jan 09
4.5
Jan 10
10
15.5
21
26.5
32
El Niño: intermediate between climate and weather
SST anomalies 12/09-1/10
El Nino brings changes in weather patterns…
How are people changing the
global environment?
Recent trends in CO2 emissions compared to IPCC scenarios
Per Capita
Fossil Fuel Use
Japan and Europe…
Why do people in the
USA use so much more
energy than the rest of
the world?
CO2 change from the present, ppm
Changes in atmospheric composition:
“Greenhouse gases”, CO2
Time from present
1000’s of years
Atmospheric methane
Changes in Sea
Level are linked to
climate through
the temperature of
the ocean and the
stranded ice on the
continents
Introductory lecture—summary
Climate means "the statistical norms of weather".
Even though climate changes are smaller than weather
fluctuations, and climate change has been observed over
geological time,
climate change nevertheless has implications for life on
earth and for societies.
To understand the challenges of climate change, we need
to understand the basic physics, chemistry and biology of
the earth, for short and long time scales, small and large
spatial scales.
Outline of the EPS 5 approach
•Study the basic physics that underlie the
functioning of the atmosphere.
•Study the basic geochemical, geophysical,
and ecological processes that regulate
atmospheric composition and climate.
•Apply the basic physics and geochemistry we
have learned to examine the scientific
concepts of environmental processes and
climate change.
•Apply what we have learned to assess the
science of climate in the context of what is
known, and unknown, about the earth system.
Environmental Science:
Atmosphere, ocean, biosphere
• What changes are occurring in the global
environment, how do we know?
• Can we discover why these changes are taking place?
• What are the consequences?
• EPS 5 starts at the beginning—the physics,
chemistry, and biology of the atmosphere, land,
and oceans—and finishes at the threshold of the
science—society interface.
Hurricanes: Have hurricanes increased in recent
decades, either in number or intensity? If so, why? Is
climate change implicated?
How do hurricanes work?
T change from the present, in oC
T changes in Antarctica
Time from the present, in 1000’s of years
Global Temperatures
Global temperature changes
over the past 1000 years
(proxy prior to 1860). From
Crowley, [2000]
Instrumental
temperature record.
From Jones et al.,
1996.
2
Norway House
Gillam
NOBS
a
0
-2
-4
-6
b
1970
1980
1990
2000
15
10
5
0
-5
-10
-15
Precipitation
anom aly, cm
Mean tem perature, °C
Thompson
Flin Flon
Lynn Lake
Temperatures at 100 cm recorded from 1994-1999 under sphagnum (low,
boggy) and feather moss (forested). These values respond to long-term
energy imbalances in the soil. They have warmed significantly during the
period of measurement.
Boreal Forest Soil Temperatures