Part one of ILSR's Compost Climate Connections series Dr. Sally Brown, University of Washington

1. The basics
It really is a case of black and white
• Composting • Landfilling

2. • Food scraps contain the perfect
blend of moisture and nutrients
• They decompose readily
• Just look in the back section of
your refrigerator
• Because they are so wet (75%
water) this decomposition gets
smelly fast
• Odor indicate anaerobic
conditions
The basics:
It really is a case of black and white
(or green, sometimes orange…)

3. Anaerobic = without oxygen
• When microbes decompose food without oxygen a range of smelly
compounds are produced
• Stinky food waste means anaerobic decomposition
• Methane (CH4) is one of the gasses you get when microbes eat food
without oxygen
• Methane happens to be a highly potent GHG (23x CO2 over 100 years)

4. Landfills
• Are much better places than refrigerators for getting food to rot
• Much better for producing methane

5. Black and White- no real comparison
• Composting
• 0.05 tons of CO2e for each wet
ton of foods scraps as CH4
• Landfilling
• 1 ton of CO2e for each wet ton of
food scraps as CH4

6. People ask about stuff that I consider to be
shades of grey (not necessarily 50 of them)

7. Transport
How do the food scraps get to the compost pile?
• Personal vehicle to composting
site
• 0.09 Mg CO2 per ton of food
scraps
• Truck (10 ton) to composting site
• 0.005 Mg CO2 per ton of food
scraps

8. Composting
Type of compost facility
• Neighborhood site
• Likely higher fugitive emissions,
will vary by intensity of
management, climate,
feedstocks
• Commercial site- time/
temperature requirements, odor
control
• Tends to be lower than home,
neighborhood piles as regulatory
requirements must be met

9. In comparison to taking it from the landfill to
the pile

10. Landfill:
End of story
• Food scraps in the landfill leak
some methane, may make some
that is captured and turned into
energy and store a bit of carbon
• Minimal impact of the material
apart from the methane

11. Compost: A long and winding road
• Composting and use of compost offers a wide range of
ancillary benefits above and beyond methane avoidance
• It is critical to consider these benefits to fully understand why
composting is critical
• Understanding these benefits gets you out of the gray and into
the broad spectrum

12. (Morris et al.,
2017)
• Climate impact (kg CO2e/kg food scraps)
• Collection and transport
• Processing
• Carbon storage
• Fertilizer displacement
• Peat displacement
• Electricity displacement
Total
Landfill
• 0.003
• 0.61
• -0.12
• -0.14
• 0.38
Compost
• 0.04
• 0.11
• -0.12
• -0.05
• -0.07
• -0.10
Can continue with carbon accounting using Life cycle assessment (LCA)

13. How about we look at it
from a bigger perspective

14. Compost improves soils
• Soils are critical for our existance
• Yes they store carbon but they also do
much much more
And what is the key to a healthy soil?

15. Let’s talk about soils

16. Dirt- the Erosion of Civilizations
• In this book he talks about how soils are the
foundation of civilization
• How if you degrade your soil you degrade and
eventually lose your civilization
National Geographic Images

17. Brown revolution
• What do you get?
• Food security
• Profitability for small farms (<1000 acres)
• Carbon sequestration
• Ecosystem resilience
• Enhanced habitat
U WI Extension

18. Soil health – key
is ORGANIC
MATTER
(Amundson et al
2015)

19. How do you regenerate soils?
• The basic keys are no- or limited tillage, cover crops
with a varied and large number of species and mulch
• Even cows can be good- with high intensity grazing
• Green manures (cover crops) are great but he also
talks about manure, compost, char and biosolids as
important options

20. How to increase soil organic matter?
(Powlson et al., 2014)
• No- till agriculture
• While good for soil, limited to no overall increases in
• SOM (0- 0.3 Mg C ha yr)

21. How to increase soil organic
matter?
(Powlson et al, 2011)
(same guy different paper)
• Organic Matter additions
• Manure- 60 kg C ha-1 yr-1 dry ton added
• Biosolids 180 kg C ha-1 yr-1 dry ton added
• Green compost 60 kg C ha-1 yr-1 dry ton
added
• At 4 tons per ha- that is 0.72 Mg ha-1 yr-1 !

22. https://www.marincarbonproject.org/

24. Brown et al., 2011
Compost and biosolids amended sites in WA State

25. California sampling(compost)
Variables related to increased carbon

26. We rely on soils for a wide range of
ecosystem services (things that nature
provides that enable us to live)
• Costanza et al., 1997
• Paper attempted to quantify the
value of ecosystem services
• US $16-54 trillion average $33
trillion
• Global GNP is $18 trillion

27. Kristen McIvor
Did her own study with
compost
Now runs a program called Harvest Pierce
County
Rate Bulk Density (gm cm -3)
Control 1.07 +/- 0.01 a
Historic amendment 0.90
Amended 2007 0.67 +/- 0.05 b
Amended 2008 0.61 +/- 0.06 b

28. Harvest Pierce County
• Community garden program in
Tacoma (80+ gardens)
• All gardens get free Tagro and
compost
https://piercecd.org/190/Urban-Agriculture

29. Tacoma program- everybody who wants it gets the compost
Takes degraded soils and makes them whole
Plot in front used ‘organic
fertilizer’
Plots in back (planted at the
same time) used biosolids
compost

30. Ecosystem services- Community Garden
Proctor Garden
https://sites.google.com/view/proctor-community-garden
Received 10 tons of compost in 2018 for 0.5 hectares
• Carbon emissions/ storage
• Climate mitigation (urban heat island)
• Water infiltration/ storage
• Stormwater diversion
• Waste management/ treatment
• Increased net primary productivity
• Soil formation

31. For this look at growth and function -/+ compost
(here biosolids compost from Tacoma)

32. How much is that worth?
(Value of ecosystem services related to use of compost on 1 hectare of land)
• Assume degraded urban soil- 20
tons of compost per ha
• Transforms the soil from minimum
function to high function
• Costanza et al (2007) sets the
value of soil at $ 6661 per
hectare per year or $8200 in
2019 $$s
• That comes to $410 per ton of
compost

33. How much is that worth?
(Value of ecosystem services related
to use of compost on 1 hectare of
land)
• Assume degraded urban soil- 20 tons of
compost per ha
• USDA has a program where farmers are
paid annually not to farm so that soils in
sensitive areas can rebuild
• We can get an estimate for the value of
compost using the rate of soil formation
and the amount of compost used at the
Proctor garden

34. How much is soil worth?
CRP Value
• Soil formation is 0.003 inches per
year
(Montgomery, 2007)
• That means it would take more
than 1800 years to build 6” of
topsoil
• Compost can do it in a month
• Based on annual CRP payments
of $128 per hectare- that comes
to $241,000 to rebuild this soil
• Or a compost value of $12,500
per ton

35. How about the impact on
people?

36. Human impact:Proctor Garden, Tacoma WA
https://sites.google.com/view/proctor-community-garden
Received 10 tons of compost in 2018 for 0.5 hectares
• Reduced crime
• Community strength
• Environmental education
• Health benefits
• Food security
• Improved diet
• Increased physical activity

37. • McGoodwins are exceptional
gardeners
• Quantified exactly what they grew/
how much in a community garden
• Food value- $4436 per 600 sq ft plot
• Proctor garden has 50 plots of a similar
size
• 50 X $1000 (because most humans
don’t grow like the McGoodwins)
• $50 000 for the garden
• Assuming compost is critical to half of
garden success = $5000 per ton of
compost

38. Increased physical activity
https://sites.google.com/view/proctor-community-
garden
Received 10 tons of compost in 2018 for 0.5 hectares
• Proctor et al (2000) estimated that
increased physical activity gave a
health care savings of $800 per
person
• Fewer doctor visits, fewer sick
days etc
• More recently that value was put
at $2500 per year per person
(Ding et al., 2016
• Have you ever worked a
community garden plot?

39. Increased physical activity- Proctor Garden
https://sites.google.com/view/proctor-community-garden
Received 10 tons of compost in 2018 for 0.5 hectares
Assuming that 1 person gardens each plot
and that each achieved half of the full
reported savings associated with increased
activity
50 individuals * 0.5 * $2500 = $50 000 for
the garden as a whole.
10 dry tons of compost /$50 000 = $5 000

40. But that is only a part of a much bigger
picture

41. Making compost can also change the lives of
the people who make it

42. GRub- Garden Raised Bounty
• 1.5 acre farm in Olympia, WA expanded to
HS in Olympia through partnership with
Gates Foundation
• GRuB develops and offers agriculture- based
employment training and drop-out
prevention programs that engage local teens
…working to break cycles of poverty,
inequality and oppression

43. GRub- Garden Raised Bounty-How much is this worth?
Average annual income > $10,000 with a HS diploma

44. SPP is a partnership between WA
DOC and Evergreen State College
with a stated mission of bringing
science and nature into prisons
Composting is an integral part of the
program

45. Monroe facility
• Vermicompost/ Black soldier fly/ Bokashi provide an alternative
model for food scraps
• Composter certification program run through UBB

47. • C0-designed and launched WSRU Vermiculture program in 2010
• Gave TEDx talk on the Power of Sustainability in 2014
• Co-published article with Dr. Sally Brown in BioCycle October 2017,
Vol. 58, No. 9, p. 34
• Co-published article with Kelli Bush in BioCycle May 2018, Vol. 59, No.
4, p. 17
• Working with UBB, SPP and Tilth Alliance, designed
curriculum for Vocational Certificate
• Peer instructor for Vermiculture and Composting
Specialist Certificate

48. • 2017 Vermiculture and Composting
Specialist Certificate
• Currently enrolled in UBB pursuing
AA degree
• Published in BioCycle May 2018,
Vol. 59, No. 4, p. 19
• From Drugs To Bugs: My journey
from a gang member to a Master
Vermiculture Specialist
http://sustainabilityinprisons.org/stories/9431/

50. Why work in prisons?
• 16,826 people incarcerated in Washington State Prisons in Feb 2019
• Incarcerated people who participate in prison education programs are
43% less likely to recidivate than those who do not.
• Prisons with college programs have fewer violent incidents, creating
safer working conditions for staff & safer living environments for
incarcerated people.
• When parents -including incarcerated ones- complete college, their
children are more likely to do so, thereby disrupting the typical cycle of
poverty & incarceration.
Vera Institute of Justice Report Highlights, 2019

51. • Methane avoidance associated with taking
food scraps out of the landfill to the compost
pile is critical
• However, if all you are focusing on is the
methane- a much bigger world is passing
you by
• Benefits associated with using the compost
extend from the people to the planet
To conclude : Don’t miss the rainbow