Transcript Forestry and Climate Change

Forestry and Climate Change - issues and
potential indicators
For UNECE/FAO Team of Specialists,
Edinburgh, 21-22 May 2007
Simon Gillam, UK
Forests and climate change
1. Carbon - how do trees affect the carbon
balance?
2. How else do trees impact on climate?
3. How does changing climate affect trees and
forest habitats?
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Simon Gillam for UNECE/FAO ToS May 2007
1. Carbon balance
Trees sequester carbon as they grow
Trees are a store of carbon
Changes to soil carbon - positive and negative
Carbon released by forest fires or deforestation
Wood fuel can replace fossil fuels
Wood products can replace steel, concrete, etc
What else?
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Simon Gillam for UNECE/FAO ToS May 2007
2. Some other impacts of forests
If climate hotter, then shade from trees (e.g.
streets and towns) becomes more valuable
… but also forests trap heat.
If more storms, forests can reduce impacts of
flooding
If water shortages, forests may be a shield
against evaporation? ... but conifers also take
up more water (not broadleaves?)
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Simon Gillam for UNECE/FAO ToS May 2007
3. Some effects of climate change
Warmer climate - more rapid tree growth
Changes to natural ranges for some species
Insects and diseases move into new areas
More storms - more windblow
What else?
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Carbon balance - what value/tonne?
Per tonne carbon or per tonne CO2
Social cost of carbon:
• wide range of estimates for current value
• carbon trading price not a good proxy
• should it increase over time?
• or should it be higher in the short run,
because of claimed urgency of action?
• discounting to get Net Present Value?
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Simon Gillam for UNECE/FAO ToS May 2007
Carbon balance - woodfuel
Common approach is just to estimate fossil fuel
carbon saved.
This assumes that the woodfuel is carbon
neutral.
Carbon emissions from woodfuel similar to
fossil fuel; so need to consider whether the
carbon sequestration balances the emissions.
Depends on where the woodfuel comes from...
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Simon Gillam for UNECE/FAO ToS May 2007
Carbon balance - SRC
Short rotation coppice
Carbon sequestered balances carbon burned
Additional benefit from carbon stored while
growing
Carbon stored in roots and stumps
Possible carbon losses from soil disturbance,
and from machinery for harvesting and
transport.
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Simon Gillam for UNECE/FAO ToS May 2007
Carbon balance - existing forests
In short run, reduces carbon stored in forests
If part of good management (e.g. thinning), rate
of carbon sequestration / hectare may be little
affected (fewer trees left, each growing more)
If bringing neglected woodlands into
management, may remove wood that would
otherwise decay, and improve tree growth
But if badly managed, may remove growing
trees that would otherwise sequester carbon
in the future - worse than using fossil fuels.
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Simon Gillam for UNECE/FAO ToS May 2007
Indicators - how to capture all this?
Carbon - sequestration rate, as well as amount
stored?
Wood fuel - quantity used, by source - JWEE?
Other wood products - sustainable use?
Anything for other impacts of forests (e.g water
- ecosystem services)?
For impacts on forests, are forest damage
indicators sufficient?
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Simon Gillam for UNECE/FAO ToS May 2007
Public Opinion Survey Q5
How much of an impact do you think climate
change will have on the UK?
 Large impact
 Slight impact
 No impact at all
 Don't know
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Simon Gillam for UNECE/FAO ToS May 2007
Public Opinion Survey Q6
Would you agree or disagree with the
following statements about the ways in
which forests and woodlands in the UK
can impact on climate change?
(1) strongly agree
(2) agree
(3) neither agree or disagree
(4) disagree
(5) strongly disagree
don't know
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Simon Gillam for UNECE/FAO ToS May 2007
Public Opinion Survey Q6
• Trees are good because they remove carbon dioxide
from the atmosphere and store it in wood
• Cutting down forests and woodland makes climate
change worse, even if they are replanted
• Using wood for fuel is better for climate change than
using fuels such as coal and gas
• Using wood for fuel makes climate change worse
because it releases carbon dioxide
• Using wood for building is better for climate change
than using materials such as concrete and steel.
• The UK could offset all its greenhouse gas emissions
by planting more trees
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Simon Gillam for UNECE/FAO ToS May 2007
Public Opinion Survey Q7
Do you agree or disagree with the following
statements regarding how UK forests and
woodlands should be managed in
response to the threat of climate change?
(1) strongly agree
(2) agree
(3) neither agree or disagree
(4) disagree
(5) strongly disagree
don't know
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Simon Gillam for UNECE/FAO ToS May 2007
Public Opinion Survey Q7
• There is nothing that anyone could do that
would make any difference
• No action is needed; let nature take its course
• A lot more trees should be planted
• Trees should not be felled in any
circumstances, even if they are replaced
• Different types of trees should be planted that
will be more suited to future climates
• More information should be provided about
the ways in which wood can be used to
lessen our impact on the environment
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Simon Gillam for UNECE/FAO ToS May 2007