introduction to earth system science

Introduction to Earth System ScienceArizona STEM Workshop

Systems Synergy: Interrelation of the Spheres

1. Some big picture Earth System Science (ESS) questionsa. our planet 700 Myr agob. our planet 50 Myr agoc. why is Earth so different?d. our planet today

2. What is ESS and why is it different?a. interaction of the spheresb. systems dynamicsc. modern society, understanding, and decision-making

3. Systems examplesa. radiative balanceb. long-term C-cycle

4. Big questionsa. The PETMb. Snowball Earthc. modern climate change

5. Concluding thoughts

Dan Schrag & Paul Hoffman; http://www.snowballearth.org/

Our planet 650 million years ago?

NASA/JPL

The north pole of our planet today

H. Brinkhaus, 2006

H. Brinkhaus, 2006

Paleogeography 50 million years ago

Geodetic Hills, Axel Heiberg island

‘Napartulik’ - Inuk for ‘Place of Trees’

Courtesy Jane Francis

H. Brinkhaus, 2006

Fossil Forest Ridge, Geodetic Hills

Buchanan Lake FormationMid Eocene fluvial sediments

(image courtesy Jane Francis)

H. Brinkhaus, 2006

• Fossil leaf litter layers represent forest floors

Courtesy Jane FrancisH. Brinkhaus, 2006

All fossil material is mummified - dried and slightly compressed


H. Brinkhaus, 2006

Some leaf litter layers are dominated by Dawn Redwood leaves (Metasequoia). These represent lowland swamp forests.


H. Brinkhaus, 2006

Metasequoia has light feathery leaves, triangular shape and an open structure, which would have been ideal for growing at high latitudes with low angle light

Metasequoia is a deciduous conifer. It was discovered first as a fossil, then found living in China


Brinkhaus, 2006

There are many fossil forests preserved within mid Eocene strata (~50 Ma) in the Canadian High Arctic

The forests lived at 80°N, within 1000 km of the North Pole,

…nearby there were also crocodiles…

Huber, 2009

Our planet 50 million years ago?

mean annual temperature (°C)

modern mean annual T: -10 to 0 °C)

modern mean annual T: 20-25 °C)

Why is Earth so different (fortunately for us) from nearby planets?

No plate tectonicsSurface T ~ 480 °CClouds of sulfuric acidAtmosphere: 92 bars;96% CO2; 3% N2

Active plate tectonicsSurface T ~ 15 °CClouds of waterAtmosphere: 1 bar;77% N2; 21% O2; 0.038% CO2

Source: http://cires.colorado.edu/science/groups/steffen/greenland/melt2005/

Welcome to the Anthropocene

Does this emitted CO2 really have an impact on CO2 concentration of the whole atmosphere?

Source: http://cires.colorado.edu/science/groups/steffen/greenland/melt2005/

Welcome to the Anthropocene

What is Earth System Science, anyway?

Disciplinary Science

Inte

grat

ion

ESS

Dec

isio

n Making

Interpretation

ES

S

Johnson et al., 2000

There are many other ways to view ESS...

http://www.cotf.edu/ete/ESS/ESSmain.html

http://serc.carleton.edu/introgeo/earthsystem/nutshell/

Earth system science is a way of understanding the Earth as a synergistic system of interrelated phenomena and reservoirs that interact through transfer of matter and energy.(paraphrased from http://esse21.usra.edu/ESSE21/)

http://www.cotf.edu/ete/ESS/ESSmain.html

http://serc.carleton.edu/introgeo/earthsystem/nutshell/

Many ESS approaches emphasize interactions among the “spheres”

lithosphere-hydrosphere-atmosphere-biosphere± cryosphere, pedosphere, asthenosphere, etc.

Many ESS approaches also emphasize

system dynamics, feedback loops, and cycles

Economic and job growth in Environmental-related fields:

A Clean Energy FutureAnother set of occupations with strong growth potential are in fields related to clean energy production and environmental protection. There are growing opportunities in these fields, particularly for workers with technical skills.For example, Figure 4 shows the past and future growth of environment-related occupations compared with all other occupations between 2000 and 2016. The environment-related jobs we consider are environmental engineering technicians (see box), environmental engineers, environmental scientists and specialists (including health), and environmental science and protection technicians (including health). Clearly, the U.S. labor market is already becoming increasingly "green" through the growth in these occupations. Jobs devoted to environmental improvement grew far faster than other occupations from 2000-2006 and the BLS projects fast relative growth through 2016. These environmental jobs account for only a small fraction of a growing list of occupations and industries that are becoming increasingly devoted to clean energy production, energy efficiency, and environmental protection.

http://www.whitehouse.gov/administration/eop/cea/Jobs-of-the-Future/

“Schendler has also learned firsthand a point that climate scientists have been making for some time: With climate change, "warming" isn't the only—or even the most serious—challenge. The sheer interdependence of complex ecosystems systems can grease you. “

Examples of industry/political interest in climate change:

•alternative energy•CO2 capture & sequestration•shifts in agriculture•rising sea level•C-footprint calculations•new shipping routes•water supply•insurance of natural disasters•impacts on ski areas, tourism, rec•long-term “weather“ prediction•human migration

“... politicians, as a species, may need to adapt to climate change as fast as polar bears. Consider the ways the electoral environment could be affected: Both major political parties could see their power bases erode as Americans, responding to warming temperatures and rising seas, flee the Republican-dominated South and Democratic-friendly coasts. Drought in the Southwest could reignite water wars between California suburbanites and Rocky Mountain swing voters. In Iowa, where floodwaters will rise more often and corn yields could suffer from heat waves and insect plagues, wanna-be presidential contenders could end up talking FEMA as much as the farm bill.

And if you think the current immigration debate is charged, wait until so-called climate refugees begin pouring in from China, Southeast Asia, and Sub-Saharan Africa. Meanwhile, on the foreign-policy front, the NOAA study projects "tensions between governments in the East and West [will] begin to fray as it is becoming clear that an entirely new level of commitment"—read: huge amounts of money—"will probably be needed to address the relationship between people and the planet."

Raupach et al. 2007, PNAS

Recent emissions

1990 1995 2000 2005 2010

CO

2 E

mis

sion

s (G

tC y

-1)

5

6

7

8

9

10Actual emissions: CDIACActual emissions: EIA450ppm stabilisation650ppm stabilisationA1FI A1B A1T A2 B1 B2

1850 1900 1950 2000 2050 2100C

O2 E

mis

sion

s (G

tC y

-1)

0

5

10

15

20

25

30Actual emissions: CDIAC450ppm stabilisation650ppm stabilisationA1FI A1B A1T A2 B1 B2

20062005

Current emissions are tracking well above the most intense fossil fuel scenario envisioned, A1FI- A1 Fossil Fuel intensive; and moving away from stabilization scenarios of 450 ppm and 650 ppm.

2007

Nature, 22 April 2010

What controls surface T of Earth?

energy flow from sun to Earth: 173,410 W

geothermal energy flow from Earth: 44 W

Albedo:

fraction of sunlight (radiant energy) reflected back into space

Atmospheric greenhouse gases:

above: dry air composition

H2O

CO2

CH4

O3

CFC-11 CFC-12

N2O

incoming

outgoing

greenhouse effect• With no greenhouse effect T = -21 °C• With greenhouse effect T = +15 °C• GHGs on Earth are the difference between ice and

liquid water: no-life and life

Some illustrative feedbacks involving:

incoming solar radiationalbedo

GHGs

rock cycle

Ts

System dynamics:

Positive feedback loop (destabilizing)

Implications of the ice-albedo feedback

1. runaway warming and loss of all ice?

2. runaway cooling and global ice cover?

chemical weathering of silicate minerals removes CO2 from the atmosphere

silicate weathering

higher T → higher precipitation and faster weathering rates

System dynamics:

Negative feedback loop (stabilizing)

silicate weathering

Implications of the long-term carbon cycle

over the last ~500 Myr the global carbon cycle has moderated Earth’s surface temperature to within ~20-30 °C

Lone Butte, North Dakota

Photo: Brett Tipple

Zachos et al., 2001

the PETM as recorded in ocean sediments

Zachos et al., 2001

The PETM•5-8 °C global warming over 10-40 kyr

•~5000 Pg of C released (this year humans release ~9 Pg C)

•major ocean acidification, dissolution of several km of limestone

•foraminiferal extinctions•major biotic shifts, climate changes

•widespread wildfires

Where did the C come from?

http://www.snowballearth.org/

Earth System Science

1. ESS is different in that it:a. regards connections between spheresb. examines states and changes vis a vis system

dynamicsc. tends to focus on effects with clear impacts on

habitability2. ESS provides a foundation for integration and

interpretation involving energy, resources, climate, land-use, biodiversity, economics, policy

3. ESS is science, not a call to personal “green virtue”...but...4. ...the stakes are high nonetheless...

introduction to earth system science

Documents

planet todaywhat

myr agoour planet

planet todayh

fossil forests

myr agowhy

fossil material

fossil leaf litter layers

fossil forest ridge