22nd MOPBangkok
Environmental Effects Assessment PanelEEAP
TEAP
SAP
EEAP
Depletion of strato-spheric ozone (O3)
Stratospheric chemistry, climate
Human health
Ecosystem health and services
Materials
Air Quality
UV-B radiation
ODS applications, cost-effective options
O3 depleting substances
Interactions with climate change
Environmental Effects Assessment Panel EEAP22nd MOP
Bangkok
KEY FOCUS AREAS FROM THE FULL ASSESSMENT REPORT 2010
Ozone depletion, climate change, UV radiation
Environmental Effects Assessment Panel
KEY FINDINGS
Strong interactions between O3 depletion & climate change
Future predictions for sun-burning UV-B radiation - effects of O3, clouds & aerosols
Consequences for human Vitamin D production
World avoided – implications for effects(UV-B radiation, 280-315 nm)
•UV-B radiation: Large variability due to clouds & aerosols
•Mid-latitudes: increased UV-B irradiances: ca 5% relative to 1980
•Large increases in UV-B radiation in areas of large O3 depletion
sufficient to induce sunburn
•S Hemisphere: cloudier overall than corresponding NH(global satellite data)
Ozone depletion, climate change, UV radiation
Currently
Ozone depletion, climate change, UV radiation
•Cloud cover increases at high latitudes (by ca 5%)
Reduction of UV radiation(UV already low)
More difficult to achieve optimal exposure times for
sufficient vitamin D production
Projected changes in ozone and clouds
•Cloud cover decreases at low latitudes by ca 3% (near the equator)
Increase in UV radiation(UV already high)
Additional increase in sunburning-UV of 3 to 6%
1980 2020 2040 2065Total chlorine (ppbv) 2 11.5 20 40O3 (DU) 310 250 220 100UV Indexmax 10 12.5 15 30
calculated using observed & currently predicted chlorine concentrations
The Montreal Protocol has PREVENTEDlarge increases in sun-burning UV radiation (UV index)
UV Index: an estimation of the UV levels important for the effects on the human skin
Human health
Environmental Effects Assessment Panel
KEY FINDINGS
Impacts of UV-B radiation on:
Increasing cataract & skin cancer incidence
Decreased immunity
Interactions with climate change
Vitamin D production
Environmental Effects Assessment Panel
Human health
• Produced in the skin following UV-B irradiation• Supports bone health
• May decrease risk of:
- several internal cancers- autoimmune & infectious diseases- cardiovascular diseases
• Effectiveness of oral vitamin D supplementation?• High vitamin D status beneficial?
Need for balancing potential beneficial effects of UV with over-exposure: Importance of vitamin D
Environmental Effects Assessment Panel
Exposure to sunburning UV-B radiationMajor environmental risk for skin cancers
M. Norval
Squamous cell carcinoma
Cutaneous malignant melanoma
Basal cell carcinoma
Non-melanoma
Human health
Human health
•Most common eye cancer in adults
•May be a link between UV-B radiation & incidence
Malignant melanoma of the eye
A. Cullen
•Occurs in ca 5-20% of the population
•Often after first spring/summer exposure
UV-induced allergy
S. Ibbotson
P. Newman, R. McKenzie
• By 2065: Peak values of sun-burning UV radiation could have tripled at mid-northern latitudes
• With the MP, clear-sky UV radiation
_only slightly greater than that prior to the
start of O3 depletionSun-burning UV radiation with and without the Montreal Protocol
World avoided:Human health protected
• Higher temperatures likely lead to more skin cancers
• For the same UV irradiance: for every 10C increase, estimated 3-6% increase in skin cancers
Human health
Combinations of climate change & solar UV radiation
Several indications of further interactions
• Increase in certain infectious diseases (malaria, Lyme)• Increase in allergic diseases• Suppression of the immune response to disease• Increased photosensitivity of the skin (temp., dust -deserts)
Decreased plant productivity in areas of large ozone depletion
Climate change & land-use change:
Regional increased UV-B radiation
UV radiation and climate change:
- Implications for food security & quality- Evolving ecosystem modifications & acclimation to UV radiation & climate
Terrestrial ecosystems
Environmental Effects Assessment Panel
KEY FINDINGS
Terrestrial ecosystems
• Plant growth is reduced in response to increased UV
ca 6% reduction in plant growth since 1980 in areas of significant ozone depletion
• Caused by: - direct damage- increased diversion of plant resources towards protection and repair processes
• Consequences:- long-term effects of reduced plant growth may be
important for potential carbon capture/retention
Plant productivity & adaptation/repair
- UV
Turnbull et al. 2005
High pigment levels
UV-B radiation causes damage in Antarctic plants
Microscopic views
Pigment loss
•Loss of green pigment
•Reduced growth
•Green pigment used for energy capture & growth
+ UV
+ UV - UV
S. Robinson N. Paul
Mosses
+ UV
+ UV
Lettuce
Many plants produce screening pigments that protect against UV damage (induced antioxidants)
Terrestrial ecosystems
Combinations of predicted climate change & UV radiation
Effects on plant and ecosystem response
Example 1 •Spread of plant pests with increasing temperature, rainfall
+ >>> UV-B radiation: large effects on plant interactions with pests
Induces increases in certain compounds
usually decreases plant consumption by e.g. insects
Important implications for food security and quality
Environmental Effects Assessment Panel
Terrestrial ecosystems
Combinations of predicted climate change & UV radiation
Effects on plant and ecosystem response
Example 2•Moderate drought: decreases UV sensitivity in plants
•But further decreases in rain + increasing temperatures:
Reduced plant growth and survival
Predicted reduced cloud cover (low latitudes)Deforestation
Land-use changes
Terrestrial ecosystems
UV radiation and global environmental change
Increased UV radiation
exposure
Example 3
Promotes decay of dead plant material
important ecosystem process for nutrient cycling
also CO2 loss to the atmosphere
Increased exposure to UV radiation with climate change
Potentially greater vulnerability to UV radiation
Changes in UV transparency of waters-Increased in some regions
-Decreased in others
Consequences for sensitivity of waterborne human pathogens to UV radiation
Environmental Effects Assessment Panel
Aquatic ecosystems
KEY FINDINGS
Environmental Effects Assessment Panel
Main factors affecting the quantity & quality of UV radiation received by aquatic organisms
Ozone layer
UV attenuation
Clouds,aerosols
Environmental Effects Assessment Panel
0
5
10
15
20
1 10 100
Dep
th, m
Irradiance as % of surface
UV-B, 305 nm
UV-A, 380 nm
Visible lig
ht
• High UV irradiance
• Low levels of dissolved organic matter >>> penetration
Penetration of UV-B, UV-A radiation and visible light in an alpine lake
Aquatic ecosystems
Environmental climate‐driven changes may exceed protective strategies to adapt to UV radiation
Climate change and solar UV radiation
Increasing temperature
increases breakdown of dissolved organic material
More UV exposure to aquatic organisms
Increasing CO2
Increases acidity (low pH)
Decreases skeletal formation in calcified organisms
more vulnerable to solar UV‐B radiation
UV radiation & climate change interactions accelerate global carbon cycling
Effect of decreased uptake of atmospheric CO2 by oceans on living organisms
Causes & consequences of increased production and release of nitrous oxide
Biogeochemical cycles
Environmental Effects Assessment Panel
KEY FINDINGS
Central to UV and climate change
Solar UV radiation
Carbon cyclingin terrestrial and aquatic
ecosystems
Climatechange
Biogeochemistryof trace gasesand aerosols
Feedbacks
• Projected warmer and drier conditions increases UV-induced breakdown of dead plant material
• Negative effects of climate change & UV radiation on aquatic organisms decrease uptake of atmospheric CO2 by the oceans
• Climate-related increases in run-off of organic material from land to oceans and UV-induced breakdown of this material increase emission of CO2 from the oceans
Biogeochemical cycles
Predicted increase in atmospheric CO2 may enhance global warming beyond current predictions
Biogeochemical cycles
Climate-related increase in run-off also increases nitrogen input in to the oceans; further N inputs from atmosphere
Increasing production of nitrous oxide, (N2O)
Increases O3-depletion Increases the GH effect
Increases UV radiation
Projected increase in tropospheric ozone(low & mid-latitudes)
Implications of changes in climate, pollutants & stratospheric O3 on human health & the environment
Likely insignificant effect of breakdown products of ODS substitutes
-hydrochlorofluorocarbons (HCFCs) -hydrofluorocarbons (HFCs)
Environmental Effects Assessment Panel
Tropospheric air quality
KEY FINDINGS
Tropospheric air quality
Future changes in UV radiation & climate will modify air quality
• UV initiates production of hydroxyl radicals (∙OH)
• A controlling factor of photochemical smog
• With O3 recovery, less UV
• ∙OH is an atmospheric ‘cleaning agent,’ destroys many air pollutants, ODS, GHGs
• ∙OH is predicted to decrease globally by ca 20% by 2100
• Potential for increased photochemical smog• Negative effects on human health, environment
Consequences
•Further increase in tropospheric O3 in mid-latitudes (ca 4 ppbv)
•Drivers used in the models for this:
- doubling of CO2
- 50% increase in emissions of plant compounds (isoprene)
- doubling of emissions of soil-derived NOx(from human activity, and from the ocean)
Predicted changes in surface ozone between 2000 & 2050 because of climate change and interactions with
atmospheric chemistry
Tropospheric air quality
TFA: currently judged to present a negligible risk to human health or the environment
Salt lakes with no outflow, loss by evaporation only – negligible effects from TFA
Small fraction of TFA from natural sources – negligible effect
Breakdown in soil and water
TFA
HFCs, HFOs, and HCFCsCF3- CXyH
O
CF3-C-OH
O
CF2Cl-C-OH
Breakdown of CFC replacements into trifluoroacetic acid (TFA)
chloro-difluoroacetic
Implications of climate change for construction materials
UV radiation degrades plastics & wood
Increased damage with high temperatures, humidity, & atmospheric pollutants
Current availability of photostabilisers as protective measures/agents
Environmental Effects Assessment Panel
Materials damage
KEY FINDINGS
Increase in Solar UV
Increase in Temp.
Increase in Humidity
Increase in Pollutants
S, NOx, O3
Polymer ++++ +++ + + Wood +++ ++ +++ +
Effect of climatic variables on light-induced degradation of materials
+, effectiveness
Improved stabilisation technologies•Allow service lifetimes of materials to be maintained or improved•Some control of deleterious environmental effects Stabilisers•Relatively high solar UV radiation stability•Plastic nanocomposites and wood-plastic composites•Nanofillers in composites
Environmental Effects Assessment Panel
Materials damage
UV radiation and climate change shorten useful outdoor lifetimes of materials
UV radiation discoloration effects on polymer pigments
•UV-caused chalking of vinyl siding & rundown with rain
•UV-caused chalking from titanium dioxide in rigid PVC
•Degraded surfaces release titanium dioxide bound in the PVC matrix
Titanium dioxide (TiO2)-photostabiliser for plastics
http://www.olympic.com/paint/Learn_How/exterior_problems.aspx
Adapted from Fabiyi et al. 2008 & Taylor et al., 2009
Products made with wood-plastic composites
Pine wood surface after 2 years of outdoor exposure
Materials damage
Use of composites to lessen UV degradation of materials
Solar UV radiation
Current & future climate change interactions with UV radiation add to the
uncertainty of many aspects of environmental
impacts
Terrestrial and aquatic ecosystems
Human health
Materials
Climatechange
LINKAGES: Environmental effects of O3 depletion & its interactions with climate change
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