430 likes | 625 Views
Acid Precipitation. Found under different forms : snow, rain, drizzle, fog… Gas : nitrous oxides (NOx) and sulphur dioxyde (SO 2 ) in the air Nature : reaction with water : production of acids. Sources : burning of fossil fuels, oil and coal-fired power plants, oil refineries, motor vehicles…
E N D
Acid Precipitation • Found under different forms : snow, rain, drizzle, fog… • Gas : nitrous oxides (NOx) and sulphur dioxyde (SO2) in the air • Nature : reaction with water : production of acids. • Sources : burning of fossil fuels, oil and coal-fired power plants, oil refineries, motor vehicles… • Impacts : acidifies lake water, tree defoliation, affects the production of maple groves, building erosion, modifies soil composition
Thinning of the ozone layer • Important for life : prevents a large quantity of UV radiations to reach the surface of the Earth. • Gas : CFC and others • Nature : when natural ozone is destroyed faster than it is produced. • Source : refrigerants, air conditioning, insulating foams release CFCs, that reach the ozone layer and destroy it. • Impacts : torrid summers, drying winds, burnt crops, melting glaciers, skin cancer and cataract formation.
Ground-level ozone • Gas : nitrous oxides and volatile organic compounds (VOC) • Nature : forms when sunlight reacts with air pollutants flotting over urban areas on hot days. • Source : refrigerants, aerosols, automobiles • Impacts : health impacts on humans, impacts on the vegetation and on painted surfaces.
Smog = Smoke + Fog • Gas : mixture of air pollutants including gases and fine particles and ground-level ozone. • Nature : chemical reaction beteween the pollutants and sunlight and heat. • Source : burning of fossil fuels, … • Impacts : Can harm human health, particularly for those who already suffer from heart and lung disease.
Weather vs. Climate • Weather : atmospheric conditions (temperature, precipitation, wind, atmospheric pressure) observed at a particular time at a specific location. • Climate : meteorological conditions forecasted for a specific location over a long period of time.
The climate is determined by many factors including : the atmosphere, the sun, the oceans, the ice cover and the land.
Changes in the climate • Over the years, changes in the climate occured naturally on the planet.
The Greenhouse Effect is… • a natural phenomenon essential to life on Earth, without which average temperatures would be 18 degrees below zero; • being amplified by an accumulation of Greenhouse Gases due to human activities.
Climate Change Evidence • Increase in global temperature during the last century; • Melting of the glaciers; • Rise of the global sea level; • Increase in the frequency of extreme weather events.
Climate Change Impacts in Atlantic Canada •On water •On human health •On fisheries •On ecosystems •On forest
Reduced water quantity and quality Impacts on hydroelectricity Impacts on fisheries & tourism Impacts on fish habitat Fresh Water
Impacts on Oceans • Impacts on marine currents (Gulf Stream, Labrador…). • Erosion and flooding in coastal areas • Impacts on the variety and quantity of marine resources • Impacts on the economy: fisheries, oil exploration & shipping. • Impacts on ice: less ice cover and less icebergs.
AgriculturePositive?Negative ? • Extreme events and damages to crops (excess moisture, droughts, hail, …) • Less snow cover (damages to certain cultures) • More insect pests • Longer growing season • Fall harvesting easier • More favorable to non traditional cultures
Environment in General • Impact on terrestrial and marine biodiversity • Impacts on species’ migrations • Impacts on native species through invasive species • Isolated populations threatened Changing Ecosystems
Impacts on Forests • Extreme weather events: damage and loss of trees • Winter thaws: damage to deciduous trees • Increase in temperatures: more insect infestations Younger and less diverse forests Impacts on forest dependant communities
Human Health • Impacts of extreme events • Vector-born diseases • Impacts on pollution and heat (smog) • Vulnerability to droughts and heat waves
Coastal communities • Sea level rise (50-70 cm) • Destruction of coastal marshes • Impacts on coastal species • Impacts to human infrastructure
CO2 Emissions per Capita in Different Countries Source:CO2 emissions data for 1998 from Energy Information Administration, US Department of Energy: World Carbon Dioxide Emissions from the Consumption and Flaring of Fossil Fuels, 1990-1999
Dealing with Climate Change • Mitigation: Reducing our emissions of greenhouse gases or enhancing GHG absorption • Adaptation: Measures in place to deal with impacts of climate change