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 others), 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

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.

Student work in EPS 5

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.

EPS 5 Writing Project information

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?

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.

Paleoclimate data from Antarctic Ice Cores

Intergovernmental Panel on Climate Change (IPCC)

ΔT Law Dome

-1

0

+1

o C

Climate has been warming…

N. HEMISPHERE TEMPERATURE: THE PAST 1000 YEARS

Antarctic Temperature: past 1000 years

Are these changes "natural"?

Climate has been warming, and sea level rising…

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

2007

The Arctic Ocean has been covered by floating ice for all human history…

…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

climate

longitude pressure scale

latit

ude

Climate: long term averages of weather

January July

Pressure anomaly scale (mb)

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.

Land Surface Temperature (C) Dec 2001—Feb 2002

Climate/weather

Infrared composite/global moll

weather, or climate?

SST Jan 09

Jan 10

4.5 10 15.5 21 26.5 32

Sea Surface Temperature

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?

Changes in atmospheric composition: “Greenhouse gases”, CO2

Time from present 1000’s of years

CO

2 cha

nge

from

the

pres

ent,

ppm

Atmospheric methane

Changes in Sea Level are linked to climate through the temperature of the ocean and the stranded ice on the continents

Outline of the EPS 5 approach

• Study the basic physics that underlie the functioning of the atmosphere.

• Study the basic geochemical and geophysical process 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?

Time from the present, in 1000’s of years

T ch

ange

from

the

pres

ent,

in o C

T changes in Antarctica

Global temperature changes over the past 1000 years (proxy prior to 1860). From Crowley, [2000]

Global Temperatures

Instrumental temperature record. From Jones et al., 1996.

Boreal Forest Soil Temperatures