7.1. Factors Affecting Climate Change

Weather Vs Climate What is the difference between weather and climate? While weather describes local conditions at a particular time, climate describes average conditions for a large region over long periods of time.

Questions? Weather vs Climate 1. It snowed 5 inches last night 2. It has not rained this month yet 3. Typically rainfall in June will be under 1 inch 4. This winter should be colder than normal Weather, weather, climate, climate

Earth’s Movement in Space Moved from the geocentric (Aristotle) notion of the world to the heliocentric (Galileo/Copernicus)

Earth’s Movement in Space The earth rotates around its own 23.5o axis in 24 hours (days) and around the sun in one year. The axis is elliptical

Variations in Earth’s Rotation, Orbit, and Tilt Eccentricity: Earth’s rotation around the sun varies from nearly circular to elliptical Due to gravitational pull from other planets Tilt: Earth’s tilt ranges from 22.1o to 24.5o over thousands of years Wobble: The Earth is not perfectly spherical causing it to wobble while rotating around its axis

Earth`s Temperature and Latitude Due to the spherical shape of the earth and the tilt, the sunlight is more concentrated at the equator and more spread out moving toward the poles

Atmosphere and Climate The Greenhouse Effect: The sun`s energy (solar radiation) enters the earths atmosphere where it is partially absorbed and partially reflected back as thermal energy Greenhouse gases (N2, O2, H2O) trap the thermal energy keeping the earth warm

Wind Movements Wind is the movement of air from a high pressure area to a low pressure area. As air is warmed by the sun, it is heated causing it to rise. As the air is rising it creates a low pressure system below it The high pressure cold air will then move towards the low pressure area in the form of wind.

Earth Tectonic Plate Movements The Earth is composed of massive pieces of solid rock floating on a viscous layer of the Earth known as the asthenosphere. Since they are floating they are constantly in motion

Tectonic Plates and Natural Disasters When two tectonic plates collide with one another, one of the plates will likely subduct (move underneath) the other plate. The friction of both large rocks causes earthquakes, volcanoes and possibly tsunamis.

7.2 Describing Climates

Describing Climates Various regions of the world share many environmental similarities due to similar weather conditions. It is therefore important to organize these regions into climate zones.

Climate Zones Tropical Zone: Between the Tropic of Cancer and the Tropic of Capricorn Warm all year Temperate Zones: Located between each of the polar zones and the tropical zones Temperature varies greatly throughout the year Distinct warm and cold seasons Polar Zones: Located approximately 66o north and south. Cold temperatures with ice coverings throughout the year

Biomes - Climate Zones (p.284-285) Based on similarities between vegetation (e.g. plants) and animals living in a specific region. Also based on climatograph (i.e. temperature and precipitation) similarities between regions.

Ecozones Use geology, landscape, soil, vegetation, wildlife, water, and human factors. Helps assess the impact of climate change Ecozones are separated from one another by a geological feature such as an ocean, desert, or mountain range.

Ecoregions Ecozones can then be subdivided into ecoregions. These regions take into account the differences in climate, wildlife, and human activities within one ecozones.

7.3 Indicators and Effects of Climate Change

Indicators and Effects of Climate Change Global warming has been one of the most important indicators of climate change. Evidence for global warming comes from melting glaciers.

Changes in Polar and Glacial Ice Overall loss of ice mass in the West Antarctic ice sheet has been measured at approximately 65km3. Raises water levels approximately 0.16mm per year. Impacts of Melting Ice The habitat of seals and polar bears is drastically changed Polar bears feed on seals through holes in the ice Ice also provides an area to rest If they do not rest, they risk drowning

Climate and Health With increasing temperatures, viruses will proliferate causing outbreaks Hanta virus Increased temperature also leads to increased pollen release and mould growth Could lead to asthma attacks

Polar Bear (Video)

Rising Sea Level and Ocean Acidity Oceans have absorbed approximately half of the carbon dioxide produced from fuel emissions over the past 200 years. Some of this gas reacts to form carbonic acid, which in turn lowers the pH of the water A change in pH threats corals and plankton (producers of the food chain)

Wind and Precipitation As temperature increases more water will evaporate at faster rates leading to increased precipitation, greater low and high pressure systems, and more unpredictable weather patterns. Increased storms, stronger hurricanes/tornadoes, and more flash flooding = increased death rates

DAY 2