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Environmental Effects Assessment Panel 22nd MOP EEAP Bangkok Stratospheric chemistry, climate SAP Depletion of stratospheric ozone (O3) UV-B radiation O3 depleting substances EEAP TEAP Air ODS applications, costeffective options Ecosystem health and services Quality Human health Materials Environmental Effects Assessment Panel 22nd MOP EEAP Bangkok KEY FOCUS AREAS FROM THE FULL ASSESSMENT REPORT 2010 Interactions with climate change Ozone depletion, climate change, UV radiation 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) Environmental Effects Assessment Panel Ozone depletion, climate change, UV radiation Currently • 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 Projected changes in ozone and clouds • 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 • 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% The Montreal Protocol has PREVENTED large increases in sun-burning UV radiation (UV index) Total chlorine (ppbv) 1980 2 2020 11.5 2040 20 2065 40 O3 (DU) UV Indexmax 310 10 250 12.5 220 15 100 30 UV Index: an estimation of the UV levels important for the effects on the human skin calculated using observed & currently predicted chlorine concentrations Human health 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 Need for balancing potential beneficial effects of UV with over-exposure: Importance of vitamin D • 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? Environmental Effects Assessment Panel Human health Exposure to sunburning UV-B radiation Major environmental risk for skin cancers Cutaneous malignant melanoma Squamous cell carcinoma Nonmelanoma Basal cell carcinoma M. Norval Environmental Effects Assessment Panel Human health Malignant melanoma of the eye • Most common eye cancer in adults • May be a link between UV-B radiation & incidence A. Cullen UV-induced allergy • Occurs in ca 5-20% of the population • Often after first spring/summer exposure S. Ibbotson World avoided: Human health protected • By 2065: Peak values of sun-burning UV radiation could have tripled at midnorthern latitudes • With the MP, clear-sky UV radiation _only Sun-burning UV radiation with and without the Montreal Protocol slightly greater than that prior to the start of O3 depletion P. Newman, R. McKenzie Human health Combinations of climate change & solar UV radiation • Higher temperatures likely lead to more skin cancers • For the same UV irradiance: for every 10C increase, 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) Terrestrial ecosystems KEY FINDINGS 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 Environmental Effects Assessment Panel Terrestrial ecosystems Plant productivity & adaptation/repair • 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 UV-B radiation causes damage in Antarctic plants • Green • Loss of green pigment used for energy capture & growth pigment • Reduced growth Pigment loss + UV - UV High pigment levels Microscopic views Turnbull et al. 2005 Many plants produce screening pigments that protect against UV damage (induced antioxidants) Mosses Lettuce + UV + UV - UV + UV S. Robinson N. Paul 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 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 Environmental Effects Assessment Panel Terrestrial ecosystems UV radiation and global environmental change Example 3 Predicted reduced cloud cover (low latitudes) Deforestation Land-use changes Promotes decay of dead plant material Increased UV radiation exposure important ecosystem process for nutrient cycling also CO2 loss to the atmosphere Aquatic ecosystems KEY FINDINGS 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 Main factors affecting the quantity & quality of UV radiation received by aquatic organisms Ozone layer Clouds,aerosols UV attenuation Environmental Effects Assessment Panel Penetration of UV-B, UV-A radiation and visible light in an alpine lake • High UV irradiance • Low levels of dissolved organic matter >>> penetration Irradiance as % of surface 1 10 100 Depth, m 0 5 10 15 20 Environmental Effects Assessment Panel Aquatic ecosystems Climate change and solar UV radiation Environmental climate‐driven changes may exceed protective strategies to adapt to 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 Biogeochemical cycles KEY FINDINGS 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 Environmental Effects Assessment Panel Carbon cycling in terrestrial and aquatic ecosystems Solar UV radiation Feedbacks Biogeochemistry of trace gases and aerosols Central to UV and climate change Climate change Biogeochemical cycles Predicted increase in atmospheric CO2 may enhance global warming beyond current predictions • 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 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 UV radiation Increases the GH effect Tropospheric air quality KEY FINDINGS 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 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 Consequences • • • ∙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 Tropospheric air quality Predicted changes in surface ozone between 2000 & 2050 because of climate change and interactions with atmospheric chemistry • 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) Breakdown of CFC replacements into trifluoroacetic acid (TFA) HFCs, HFOs, and HCFCs CF3- CXyH chlorodifluoroacetic O Salt lakes with no outflow, loss by evaporation only – negligible effects from TFA O CF2Cl-C-OH CF3-C-OH TFA Breakdown in soil and water Small fraction of TFA from natural sources – negligible effect TFA: currently judged to present a negligible risk to human health or the environment Materials damage KEY FINDINGS 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 Effect of climatic variables on light-induced degradation of materials +, effectiveness Polymer Wood Increase in Solar UV Increase in Temp. Increase in Humidity Increase in Pollutants S, NOx, O3 ++++ +++ + + +++ ++ +++ + Materials damage UV radiation and climate change shorten useful outdoor lifetimes of materials 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 UV radiation discoloration effects on polymer pigments • UV-caused chalking from titanium dioxide in rigid PVC • Degraded surfaces release titanium dioxide bound in the PVC matrix • UV-caused chalking of vinyl siding & rundown with rain Titanium dioxide (TiO2)photostabiliser for plastics http://www.olympic.com/paint/Learn_How/exterior_problems.aspx Materials damage Use of composites to lessen UV degradation of materials Pine wood surface after 2 years of outdoor exposure Products made with wood-plastic composites Adapted from Fabiyi et al. 2008 & Taylor et al., 2009 LINKAGES: Environmental effects of O3 depletion & its interactions with climate change Terrestrial and aquatic ecosystems Solar UV radiation Current & future climate change interactions with UV radiation add to the uncertainty of many aspects of environmental impacts Human health Materials Climate change