1. Environmental Effects Assessment Panel
8th ORM, Geneve
Environmental Effects Assessment Panel
EEAP
Influences of Ozone Layer Depletion and Climate Change on UV-radiation: Impacts on Human Health and the Environment Janet F. Bornman and Nigel D. Paul, co-chairs

2. Stratospheric chemistry, climate O3 depleting substances
EEAP
Stratospheric chemistry, climate
Depletion of strato-spheric ozone (O3)
UV-B radiation
O3 depleting substances
Human health
Ecosystem health and services
Materials
Air Quality
ODS applications, substitutes

3. Environmental Effects Assessment Panel EEAP
The role of the Environmental Effects
Assessment Panel
Effects of ozone depletion
Effects of climate change
Consequences for life on Earth

4. Environmental Effects Assessment Panel (Full Assessment Report 2010)
EEAP
KEY FOCUS AREAS
(Full Assessment Report 2010)
UV changes in relation to impacts: Human health Terrestrial ecosystems Aquatic ecosystems Carbon and other global chemical cycles Air quality Materials
INTERACTIONS
Ozone depletion, climate change, UV radiation

5. Ozone depletion, climate change, UV radiation
KEY OUTPUTS
Assessment of future predictions of the effects of O3, clouds & aerosols for:
UV-B radiation causing sun-burn
UV-B radiation involved in human vitamin D production
Ecosystems, construction materials
*UV-B radiation, nm
Environmental Effects Assessment Panel

6. Ozone depletion, climate change, UV radiation
Current UV-B radiation compared with 1980
Measurable effects of ozone depletion but also large variability in UV-B radiation due to clouds & aerosols
Southern Hemisphere cloudier overall than corresponding Northern Hemisphere (global satellite data)
At high latitudes (areas of large O3 depletion): large increases in UV-B radiation
Sufficient to cause sunburn
At mid-latitudes: increases in UV-B radiation by ca 5%
Environmental Effects Assessment Panel

7. Ozone depletion, climate change, UV radiation
Projected future changes in UV: ozone and clouds
At high latitudes: cloud cover increases (by ca 5%)
Reduction of UV radiation
(UV already low)
Less easy to achieve exposure times needed to produce sufficient vitamin D
At low latitudes (near the equator): cloud cover decreases by ca 3%
Increase in UV radiation
(UV already high)
Greater risk of sun-burn: additional increase in sunburning-UV of 3 to 6%
highlighting the take-home message about “health-related UV”.
Environmental Effects Assessment Panel

8. The Montreal Protocol has PREVENTED large increases in sun-burning UV
1980
2020
2040
2065
Total chlorine (ppbv) 2
11.5 20 40
O3 (DU)
310
250
220
100
Maximum UV Index 10
12.5 15 30
UV Index: an estimation of the UV important for damage to human skin
Reference future calculated using observed & currently predicted chlorine concentrations
Environmental Effects Assessment Panel

9. Skin and eye diseases (especially cancers) on human health, including:
KEY OUTPUTS
Skin and eye diseases (especially cancers)
Assessment of the effects of UV radiation, and interactions with other environmental change,
on human health, including:
Immune responses
Vitamin D production
Environmental Effects Assessment Panel

10. Human health
Exposure to sunburning UV-B radiation is a major environmental risk for skin cancers
Cutaneous malignant melanoma
The Montreal Protocol has PREVENTED
large increases in skin cancers that would have resulted from uncontrolled ozone depletion
ALTHOUGH incidence currently is high
Squamous cell carcinoma
Basal cell carcinoma
Non-melanoma
M. Norval
Environmental Effects Assessment Panel

11. Environmental Effects Assessment Panel
Human health
Malignant melanoma of the eye
Most common eye cancer in adults and may be a link between its incidence and UV-B radiation
A. Cullen
UV-induced allergy
Occurs in ca 5-20% of the population often after first spring/summer exposure to UV radiation
S. Ibbotson
UV-induced immune-suppression
Complex effect but increased UV exposure may have significant effects on infectious diseases and auto-immune diseases
Environmental Effects Assessment Panel

12. Human health
Need to balance the risks of over-exposure to UV radiation with the potential beneficial effects
Importance of vitamin D
Vitamin D is 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 supplements, and the health effects of very high vitamin D status are both unclear
Environmental Effects Assessment Panel

13. Environmental Effects Assessment Panel
Human health
Solar UV-B at mid- high latitudes are below that required for adequate Vitamin D synthesis from Autumn-Spring
Balance between sun-burning UV-B radiation and that needed for vitamin-D, and the effects of future environment change remain unclear
Environmental Effects Assessment Panel

14. Human health Combined effects of climate change & solar UV radiation
Higher temperatures may lead to more skin cancers
For the same UV exposure, for every 10oC increase, there is an estimated 3-6% increase in skin cancers
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)
Environmental Effects Assessment Panel

15. Terrestrial ecosystems
KEY OUTPUTS
Assessment of effects of ozone depletion since 1980 on current plant productivity
Food security & food quality
Assessment of the effects of future changes in UV radiation, and interactions with other environmental change on:
Ecosystem responses to UV radiation & climate
Environmental Effects Assessment Panel

16. Terrestrial ecosystems
Plant growth has been reduced by ca 6% in response to increased UV radiation in areas of significant ozone depletion
Growth reductions are due to direct damage plus diversion of plant resources towards protection and repair
- UV
Green pigment used for energy capture & growth
Loss of green pigment
Reduced growth
+ UV

17. Terrestrial ecosystems
Plant growth has been reduced by ca 6% in response to increased UV radiation in areas of significant ozone depletion
long-term effects of reduced plant growth may be important for potential carbon capture/retention
Interactions with other components of climate change

18. Terrestrial ecosystems
Combined effects of predicted climate change & UV radiation: plants and ecosystems
Increasing temperature, rainfall leads to spread of plant pests
- Increased UV-B radiation: large effects on plant interactions with pests because of induced chemical compounds
Moderate drought: decreases UV sensitivity in plants
- More frequent drought & rising temperatures reduce productivity
Important implications for food security and quality
Environmental Effects Assessment Panel

19. Terrestrial ecosystems
Combined effects of predicted climate change & UV radiation: plants and ecosystems
Climate-change-related reduced cloud cover (low latitudes)
Deforestation and other land-use changes
Effects on important ecosystem processes including nutrient cycling and CO2 loss to the atmosphere
Increased UV radiation exposure
Promotes decay of dead plant material
Reduces plant biomass production
Environmental Effects Assessment Panel

20. Terrestrial ecosystems
Impacts of climate change & land-use change on organisms and ecosystems
Impacts of climate change & changes in stratospheric ozone on UV radiation (includes increased UV-B radiation in some regions)
Implications for food security & food quality
Ecosystem responses to UV radiation & climate
Environmental Effects Assessment Panel

21. Aquatic ecosystems
KEY OUTPUTS
Assessment of the effects of future changes in UV radiation, and interactions with other environmental change on:
Aquatic organisms and ecosystem processes
Sensitivity of waterborne human pathogens to UV radiation
Environmental Effects Assessment Panel

22. Environmental Effects Assessment Panel
Aquatic ecosystems
Ozone layer
Clouds,aerosols
UV attenuation
Main factors affecting the quantity & quality of UV radiation received by aquatic organisms
Environmental Effects Assessment Panel

23. Penetration of UV-B, UV-A radiation & visible light
Aquatic ecosystems 5 10 15 20 1
100
Depth, m
Irradiance, % of surface
UV-B, 305 nm
UV-A, 380 nm
Visible light
Dissolved organic matter determines UV penetration into water
Quantity & quality of UV radiation received by aquatic organisms depends on:
Water properties
Ozone levels
Clouds
Elevation
Penetration of UV-B, UV-A radiation & visible light
in an alpine lake
High UV irradiance
Low levels of dissolved organic matter – increased penetration

24. Environmental Effects Assessment Panel
Aquatic ecosystems
Changes in climate and UV are expected to:
- Increase inputs of organic matter in some areas of the oceans
Increase the degradation of dissolved organic matter
The balance will vary between different oceanic regions, but in many areas, aquatic organisms will be exposed to increased UV radiation
Dissolved organic matter is a key limiting factor for UV penetration in to water bodies
Environmental Effects Assessment Panel

25. Aquatic ecosystems
Combined effects of predicted climate change & UV radiation: global change processes
Environmental climate‐driven changes may exceed protective strategies to adapt to UV radiation
Increasing temperature
increases breakdown of dissolved organic material
More exposure of aquatic organisms to solar UV-B
Increasing CO2
Increases acidity (low pH)
Decreases skeletal formation in calcified organisms
Increased vulnerability to solar UV‐B radiation
Environmental Effects Assessment Panel

26. Aquatic ecosystems Implications for food security
Impacts of changes in temperature, CO2 and acidity on aquatic organisms and ecosystems
Impacts of climate change & changes in stratospheric ozone on UV radiation penetrating into water bodies
Implications for food security
Ecosystem response to UV radiation & climate
Environmental Effects Assessment Panel

27. Carbon and other global chemical cycles
KEY OUTPUTS
Assessment of the effects of future changes in UV radiation and interactions with other environmental change on:
The cycling of carbon and other elements
The potential for “feedbacks” through changes in global element cycles
Environmental Effects Assessment Panel

28. Carbon and other global Environmental Effects Assessment Panel
chemical cycles
to reinforce the point that this sections builds on processes introduced in the previous sections.
Ecosystem responses to UV radiation and climate change will affect global chemical cycles, resulting in feedbacks into environmental change and its effects
Environmental Effects Assessment Panel

29. Carbon and other global Environmental Effects Assessment Panel
chemical cycles
Interactions between continuing changes in UV radiation and the effects of other components of environmental change are diverse and complex
Interactions are best defined in the oceans and involve:
- Decreased uptake of atmospheric CO2 by the oceans
- Increased production and release of nitrous oxide from the oceans
Ecosystem response to UV radiation and climate change will affect global chemical cycles, resulting in feedbacks into environmental change and its effects
Environmental Effects Assessment Panel

30. Carbon and other global
chemical cycles
Negative effects of climate change & UV radiation on aquatic organisms
Decreased CO2 uptake by the oceans
Increased run-off of organic matter from land into the oceans
UV-induced breakdown of this organic matter
Increased CO2 emissions from the oceans (also increased NOx )
Resulting increase in atmospheric CO2 may enhance global warming beyond current predictions
Environmental Effects Assessment Panel

31. Carbon and other global Environmental Effects Assessment Panel
chemical cycles
Environmental Effects Assessment Panel

32. Tropospheric air quality Environmental Effects Assessment Panel
KEY OUTPUTS
Assessment of the interactive effects of ozone depletion and other components of environmental change on tropospheric ozone (at low & mid-latitudes), and other tropospheric air pollutants
Assessment of effects on human health and ecosystems of breakdown products of ODS substitutes (HCFCs and HFCs)
Environmental Effects Assessment Panel

33. Tropospheric air quality Environmental Effects Assessment Panel
UV initiates production of hydroxyl radicals (∙OH), which are atmospheric ‘cleaning agents,’ destroying many air pollutants, ODS, photochemical smog
With O3 recovery, less UV, as a result ∙OH is predicted to decrease globally by ca 20% by 2100
Potential for increased photochemical smog, with negative effects on human health and the environment
Environmental Effects Assessment Panel

34. Tropospheric air quality
Surface (tropospheric) O3 in mid-latitudes is predicted to increase because of climate change and interactions with atmospheric chemistry
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)

35. Tropospheric air quality Environmental Effects Assessment Panel
CFC replacements break down into trifluoroacetic acid (TFA) but this is currently judged to present a negligible risk to human health or the environment
Environmental Effects Assessment Panel

36. Materials damage
KEY OUTPUTS
Assessment of effects of UV radiation and climate change on construction materials
UV radiation degradation of plastics & wood
Damage due to high temperatures, humidity, & atmospheric pollutants
Assessment of availability of technologies as protective measures/agents
Environmental Effects Assessment Panel

37. +, effectiveness Materials damage
Effect of climatic variables on light-induced degradation of materials
+, effectiveness
Environmental Effects Assessment Panel

38. Pine wood surface after 2 years of outdoor exposure
Materials damage
UV radiation and climate change shorten useful outdoor lifetimes of materials
Development of technologies to counteract these effects of UV radiation and climate change
- allows service lifetimes of materials to be maintained or improved
Use of plastic nanocomposites & wood-plastic composites
Increased use of nanomaterials as stabilisers
Pine wood surface after 2 years of outdoor exposure
Improved stabilisation technologies
allow service lifetimes of materials to be maintained or improved, despite increased solar UV-B levels
can control the deleterious effects of environments with enhanced UV radiation and temperature to some extent and only for some types of the common plastics
relatively high solar UV stability
Plastic nanocomposites and wood-plastic composites
use of nanofillers in composites is effective
Environmental Effects Assessment Panel

39. Environmental Effects Assessment Panel
8th ORM, Geneve
Environmental Effects Assessment Panel
EEAP
Solar UV
radiation
Terrestrial and aquatic ecosystems
Human health
Materials
Climate
change
Current & future climate change interactions with UV radiation add to the uncertainty of many aspects of environmental impacts
While many of the processes are defined, the magnitude of the effects remains a challenge.