TEP Seminar XI Trees: the key to climate proofing our cities

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TEP Seminar XITrees the key to climate proofing
our cities
Tree-related risks a perspective from the Stern
report
Whereer you walk, cool gales shall fan the
glade, Trees, where you sit, shall crowd into a
shade. Alexander Pope 1688-1744

• David Ball
• Centre for Decision Analysis Risk Management,
  Middlesex University
• www.mdx.ac.uk/risk

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What is the Stern report?
Stern Review on the Economics of Climate
Change In 2006 Sir Nicholas Stern, Adviser to the
Government on the economics of climate change and
development, presented his report on the
Economics of Climate Change.
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Selected Conclusions

• average air temperatures could rise by 5ºC
• deforestation is responsible for more greenhouse
  gas emissions than transport
• climate is the biggest market failure ever seen
• deforestation should be curbed urgently

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Towns and cities will suffer more due to the
urban heat island effect
Ref Tony Chandlers The climate of London and
As cities grow, they impact local and regional
climates, including temperature averages and
extremes. Temperature changes affect urban
dwellers in many ways, influencing their health
and comfort, energy costs, air quality and
visibility levels, water availability and
quality, ecological services, recreation, and
overall quality of life.
Source Arizona State University
http//asusmart.com/urbanclimate.php
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Urban heat islands are caused by

• heat generation in the city
• surface reflectivity
• fewer trees, shrubs and plants to shade
  buildings, intercept solar radiation, and cool
  the air by evapotraspiration

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Impact of hot temperatures on death in London a
time series approach S Hajat1, R S Kovats1, R W
Atkinson2, A Haines1 1 London School of Hygiene
and Tropical Medicine, London, UK 2 St George's
Hospital Medical School, London, UK
There is a 3 increase in deaths in London for
every one degree increase in temperature above 21
ºC.
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Its about
PLANTING TREES PROPERLY
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Source http//heatisland.lbl.gov/Vegetation/Plant
ing.html
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The threat of the safety meme
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The invasion of the safety meme
Evolutionary theorist and biologist Richard
Dawkins coined the term meme in 1976. He gave
as examples tunes, catch-phrases, beliefs,
clothing fashions. Wikipedia, 2007
It also applies to ideas. Ideas (ways of
thinking) can spread like viruses..
Richard Dawkins
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According to Judith Hackitt (Chair of the HSE),
and others

• Elf n Safety is now a serious irritation e.g.
• banning of pancake races and wet T-shirt
  competitions
• Santa Claus and his sleigh
• plastic swords in a village pantomime

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THE NATIONAL ELF SERVICE
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Elf n safety is in some sense out of control.
It doesnt even think much about elf. Its
almost exclusively about reducing risk of injury,
property damage and legal liability.
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How elf n safety pits safety against health
Metro 16 March 2004
and thereby kills people.
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Thats why we need a new approach
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HSEs slogan is Managing risk properly
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Managing trees properly
Benefits of trees
Risks posed by trees