Slides for GGR 314,Global Warming

Chapter 3: The Carbon Cycle

Course taught by

Danny HarveyDepartment of Geography

University of Toronto

Exhibit 3-1: The pre-industrial carbon cycle

Atmosphere 560

Soil & Detritus 5400

Biota720

Surface Water 560

Biota 3

Deep Ocean 34,000

120 60M

60-M-R

R

aR 100 100

5040

10(1-a)R 10

Net Flux = B

B

Exhibit 3-2: Collapsing vegetation and exposure of previously frozen C-rich soils as permafrost warms

Source: http://www.globalcarbonproject.org/news/SoilOrganicPoolsinPermafrost.html

Exhibit 3-3: A carbon rich soil above permafrost (left) and ice wedges in permafrost (left)

Source: http://www.globalcarbonproject.org/news/SoilOrganicPoolsinPermafrost.html

Exhibit 3-4: Diatoms, depicted below, have SiO2 (siliceous, made of silica) skeletons

Source: Wikipedia, Open Source photo in article on plankton

Exhibit 3-5: Coccoliths (left) and foraminifera (right) have calcium carbonate (calcareous) skeletons

Source: Left, Wikipedia, Richard Lampitt and Jeremy Young in article on “Coccolithophore” Right, Wikipedia article on “Foraminifera”, author Psammophile

Width of image: 5.5 mm

Exhibit 3-6: Geographical variation in net primary productivity of the world’s oceans

Source: Schlesinger (1991)

Exhibit 3-7: Variation of potential pCO2 in the low-latitude ocean

Source: Broecker and Peng

Exhibit 3-8: Impulse responses – the variation in the amount of a GHG remaining in the atmosphere after a “pulse” (sudden) emission at time t=0.

0.0

0.2

0.4

0.6

0.8

1.0

0 50 100 150 200

Years after Impulse

Fra

ctio

n o

f In

ject

ed G

as R

emai

nin

g

in t

he

Atm

osp

her

e CO2

CH4

N2O

Source: Harvey (2000, Global Warming: The Hard Science, Prentice Hall)

Exhibit 3-9: Simulated variation in the terrestrial biosphere sink using theLPJ dynamic global vegetation model driven either by observed

temperature and precipitation variations (CRU Climatology) or withoutput from two climate models

Source: Fischlin et al (2007, IPCC AR4, WGII)

Exhibit 3-10: CO2 emissions and CO2 sinks for a scenario where trend of increasing emissions turns around between 2010-2020.

Source: Harvey (1989, Climatic Change, Vol. 15, 343-381)

Exhibit 3-11: Methane escaping from thawing yedoma (loess) soils in Siberia

Exhibit 3-12: Sonar image of methane bubbles rising from the sea floor along a 2.5 km segment in 250-m deep water west of Svalbard (Arctic

Ocean)

Source: Kerr (2010, Science, Vol. 329, 620-621)

Video, methane from frozen lakes, ignitedhttp://www.youtube.com/watch?v=oa3M4ou3kvw

Methane bubbling from lakeshttp://www.youtube.com/watch?v=eM5WPl69Z18&feature=related

Methane bubbling from lakeshttp://www.youtube.com/watch?v=eM5WPl69Z18&feature=related

Exhibit 3.13a: CO2 stabilization scenarios

Exhibit 3-13b: Range of CO2 emissions permitted for the various stabilization scenarios