22nd MOP Bangkok Environmental Effects Assessment Panel EEAP.

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)


Currently


•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


KEY FINDINGS

Impacts of UV-B radiation on:

Increasing cataract & skin cancer incidence

Decreased immunity

Interactions with climate change

Vitamin D production


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


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


KEY FINDINGS


• 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)


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



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


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


Aquatic ecosystems

KEY FINDINGS


Main factors affecting the quantity & quality of UV radiation received by aquatic organisms

Ozone layer

UV attenuation

Clouds,aerosols


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


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


Predicted increase in atmospheric CO2 may enhance global warming beyond current predictions


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)


Tropospheric air quality

KEY FINDINGS


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


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


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


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

22nd MOP Bangkok Environmental Effects Assessment Panel EEAP.

Documents

uv slide

reduction of uv radiation

uv radiation uv index

uvb radiation effects

effects uvb radiation

uv turnbull

uv lettuce

uv irradiance