The economic case for trees

Local Government Association – Harrogate, 1st July 2015Tim Sunderland, Principal Specialist in Economics, Natural England

The best time to plant a tree is twenty years ago.The Second best time is today.Chinese Proverb

Image from http://pixabay.com/en/park-london-england-nature-uk-737228/

Accountancy icon from: http://commons.wikimedia.org/wiki/File:Accountancy_template.svg?uselang=en-gbEconomics icon from: http://pixabay.com/en/justice-scales-orange-libra-311699/

Accountancy Economics

vsCosts

Benefits

Is about ‘counting money’

Is about ‘value for money’

Benefits provided by trees Air-Quality

Carbon Sequestration

Local climate moderation

Stopping Erosion

Reducing Flooding

Filtering Water Pollution Noise

AbatementSoil Quality

Beauty

http://pixabay.com/en/oak-tree-branches-tall-nature-303884/

Wildlife Habitat

Trees provide a range of benefits not featured in the accounts

Valuing Benefits

Ideally you want to prove, then quantify, then value benefits. Often we ‘get stuck’ at prove or quantify

Trees and their benefits for Flood Risk Mitigation

Soil permeability

5 – 8 times

In broadleaf woodland than grassland (3)

Urban Forests

Peak run off (5)

1 Street Tree

50 – 62%

In storm water run off over 9m area (6)

4 Sites 40 Hectares of trees

1 hour in major flood (4)

40%in field scale flood peaks (2)

A shelter belt can lead to a

Moorland Catchments

than forested ones (1)

http://pixabay.com/en/flooded-disaster-flooding-flood-491245/

Trees and their benefits for Pollution mitigation

Particulate Matter Accumulation

10 – 20 fold

Between species: Mountain Pine, Silver Birch, Stephanandra, Skimmia, Grey Willow and Scots Pine the best (9)

711,000 tonnes

of pollution in US urban areas each year (7)

Modelling estimates

Urban Forests

Ozone Pollution

(10)

547 Ha mixed GreenspaceReduces pollution and

2 Deaths &2 Hospital Admissions

each year (8) Picture from http://pixabay.com/en/london-car-taxi-city-uk-england-676785/

Trees and their benefits for Climate Change mitigation

Above ground storage of C in Leicester

231,521 t 97% in

1 LargeTree

450 litres of H20 and

each day and reduces urban temperatures (11)

1,000 megajoules

Tree Shelterbelt

Office heating energy by

3.64 kw per sqmOr 18.1% of total (13)

New Forest

5 degrees celsius

River Shading by trees

water temperatures

lower than rivers in open grassland (15)

Urban Parks are

1%than built up Areas(12)

Image from http://tools.decc.gov.uk/nationalheatmap/

Trees and their benefits for Noise mitigation

1 Tree Belt

3.6 m wide 4.0m high

sound levels by

4 decibels (16)

Picture from http://pixabay.com/en/los-angeles-la-usa-america-city-498285/

Trees and their socio-economic benefits

Business districts with trees

Shoppers will be

Travel Further Stay Longer Visit more frequently Pay more (17)

Live near Greenery

CRIM

E (1

9)TREES

Picture from http://pixabay.com/en/building-architecture-majorca-spain-500337/

http://www.telegraph.co.uk/news/earth/8476747/The-13-year-old-who-has-the-world-planting-trees.html

Felix FinkbeinerAt 9 Felix started a foundation which has planted a million trees in Germany. It started as a homework project!

Torbay’s urban forest

• 818,000 trees• 11% forest cover• Most common trees are;

Leyland Cypress, Ash and Sycamore

• Most important by leaf area are; Ash, Sycamore, Beech and Hazel

• 71% of trees were in private ownership – but these are smaller ones

Picture from: http://pixabay.com/en/boats-marina-quayside-harbourside-445080/

Benefits provided by trees Air-Quality

Carbon Sequestration

Local climate moderation

Stopping Erosion

Reducing Flooding

Filtering Water Pollution Noise

AbatementSoil Quality

Beauty

http://pixabay.com/en/oak-tree-branches-tall-nature-303884/

Wildlife Habitat

Our analysis could only include the circled benefits

Snapshot Results

The proportion of the trees’ cost justified by carbon and air-quality benefits

37% 1% 46% 209%

Results: air pollution removal

Air pollution per tree increased with age due to tree growth

Results: annual carbon sequestration

Carbon Sequestration also increased with age due to tree growth

Proportion of costs justified by air-quality and carbon sequestration benefits alone

37% 1% 46% 209%76% 1% 79% 479%

3.5%2.1%

At Discount Rate of:

Wangari Maatthai – “ I started planting trees and found myself and the forefront of fighting for the restoration of democracy in my country”

Picture from http://www.greenbeltmovement.org/wangari-maathai/biography

A society prospers when old men plant trees in whose shade they know they will never sit Greek Proverb

Image from http://pixabay.com/en/tree-oak-landscape-view-field-402953/

Contact Details and References

Contact Details•Tim Sunderland, Principal Specialist in Economics, Natural England•E-mail: tim.sunderland@naturalengland.org.uk

References •MEBIE review for all references except Torbay: http://publications.naturalengland.org.uk/publication/6692039286587392•Torbay study http://www.tandfonline.com/doi/abs/10.1080/03071375.2012.701416