Contact details.
Name / Organisation Name: Environment Agency
Direct Contact: Tony Burch.
(if submitting on behalf of an organisation)
Address:
Environment Agency
Colvedene Court
Wessex Way
Colden Common
Winchester
Hampshire
SO21 1WP
Please tick box for most appropriate category:
X Physical Environment (incl. biodiversity, coast, landscape)[Deadline 25th April]
Infrastructure (incl. transport) [Deadline 23rd May]
Wellbeing and society [Deadline 20th June]
Economy [Deadline 1st August]
Other [1st August]
Please note deadlines for evidence submission, evidence on each category
must be submitted prior to deadline. If you are unsure which category to
submit your evidence under please email: climate.commission@hants.gov.uk
or telephone 01962 846828
Detail of Evidence:
Executive Summary:
Sea level rise is a physical phenomenon that is likely to have social,
economic and environmental consequences for communities along the
Hampshire coastline.
If so, coastal communities need a clear vision of how their natural and
urban coasts will look and function in 50 to 100 years time when the
sea will be higher.
They then need to develop an integrated adaptation strategy and
adopt long term multi-sector policies to achieve that vision.
1. Introduction
The debate over whether or not climate change is happening is over. The
issues we now have to deal with are: how can we adapt to the effects of
climate change that are happening and will continue to happen over the
coming decades due to past pollution (climate change momentum), and how
can we mitigate future changes.
Estimates of how long existing climate change momentum and its effects will
last vary from 30 to 50 years. This means that communities along the
Hampshire coast have 30 to 50 years of sea level rise to adapt to before they
may benefit from mitigating measures which countries may make now or in
the future.
2. EVIDENCE FOR THREATS IN HAMPSHIRE
2.1 Sea Level Rise
In late 2006 the Department of the Environment Food and Rural Affairs 1 and
the Communities and Local Government2 agreed and published new net sea
level rise allowances3 that should be used for decision making.
Table 1 & Fig 1 show the previous and the new allowances for Hampshire.
Region
SE England
(Hampshire)
Assumed
Vertical Land
Movement
(mm/yr)
- 0.8
Net Sea Level Rise (mm/yr)
2006 Allowances
19902025205520852025
2055
2085
2115
4.0
8.5
12.0
15.0
Previous
Allowance
6mm/yr
constant
Table 1. Net Sea Level Rise Allowances (Defra & DCRA 2006)
The new 2006 Allowances reflect an exponential curve; they replace the
Previous Allowance of a constant 6mm/year. The publication of the new
allowances is an important and significant development for coastal
communities. It is a switch from a constant rate of sea level rise to an
accelerating rate of sea level rise which begins to run away from the previous
allowance during the second half of the century (ie. after 2055 the rate of sea
level rise allowance accelerates from 6mm/year to12 and then to 15mm/year).
1
2
3
Flood & Coastal Defence Appraisal Guidance 3, Economic Appraisal Supplementary Note - October 2006
Planning Policy Statement 25 - December 2006
Net sea level rise allowances incorporate thermal expansion of the oceans and melt from land glaciers
and vertical adjustments of the land. Additional contributions from tidal surges and waves are not
included.
On the basis of the new 2006 allowances both normal and extreme sea levels
along the Hampshire coast will be 0.4m higher in 2055 and 1.2m higher in
2115 than they were in 1990.
Sea level rise along the Hampshire coast of this sort of magnitude is an issue
that is likely to affect very many sectors of local society. It has not been faced
before. Common sense tells us it will affect the natural, the built, the social
and the economic coastal environments in varying degrees depending on
their vulnerability.
Amongst other things it could affect:
 the economy (employment, urban growth and regeneration),
 social wellbeing and public safety (flood risk, health, employment and
housing),
 tourism and recreation (beaches will get narrower, marinas, quays and
coastal paths will be affected),
 transport (docks, quays and coastal roads will need to be modified),
 underground services and infrastructure will be submerged by higher
coastal fringe groundwater levels & may need to be modified.
 pollution and public health (land affected by contamination and land-fill
sites along the coast will be vulnerable to higher sea and coastal
ground water levels)
 water supply (coastal aquifers may be vulnerable to saline intrusion)
 coastal biodiversity (water levels at coastal & estuarine habitats will
rise)
 coastal processes will change with unknown consequences to coastal
currents, morphology, habitats, fisheries etc.
3. SOLUTIONS AND ACTIONS REQUIRED TO CLIMATE CHANGE
3.1 Sea Level Rise
Sea level rise is now a 'reality' that cannot be stopped in the foreseeable
future. Communities need to start thinking now about how they can adapt to
sea level rise and its consequences for them over the next decades.
This adaptation requires a clear vision of what Hampshire's natural coast and
urban waterfronts are going to look like and how they are going to function as
economic, social and ecological assets in 50 to 100 years time when the sea
will be higher. Leadership, imaginative thinking, community involvement and
bold, farsighted policies across numerous sectors will be needed to bring
about that vision.
This does not mean abandoning waterfronts to the sea or residing and
working behind ever-higher sea defences. It means imaginative spatial
planning, urban design, architecture and infrastructure that can adapt to the
rising sea levels.
To stimulate debate here are three basic adaptation options:
1. New development (including access roads, highways and services)
along the waterfront and in other vulnerable locations would be raised
in level. As the decades pass by, more and more of these areas would
be redeveloped and elevated and continue to flourish. Over the
generations the elevated waterfronts would coalesce.
2. Protect people and existing / new development with sea defences,
flood resilience measures and emergency response plans. This has
residual dangers due to the risk of overtopping and long term
maintenance and renewal problems and it could disconnect people
from the sea they are there to enjoy and profit from.
3. Retreat from the waterfront and build on higher ground.
We advise that coastal communities should:
 research the impact of a range of sea level rise scenarios on all of their
interests,
 consider the consequences of these impacts over time and their
sensitivity to the different scenarios, including the vulnerability of people,
assets and the local economy to sea level rise,
 consider if they can live with or how they can avoid or adapt to these
consequences over the coming decades,
 produce a clear vision of their natural coast and their urban waterfronts in
50 to 100 years time when the sea will be significantly higher than it is
now,
 develop an integrated, long term, multi-sector adaptation strategy and
adopt long term policies that will deliver that vision over the coming
decades.
 consider the formation of a multi-sector sea level rise forum or group to
raise awareness of and community involvement in sea level rise and how
their community might adapt to it.
In the meantime apply PPS 1 Delivering Sustainable Development (ie. take
into account the need to avoid using naturally hazardous land, such as flood
plains, to meet the expected needs for growth) and PPS 25 Development and
Flood Risk.