Climate and Climate Change Science
Climate • climate – the average weather pattern of a region. This includes temperature, precipitation, winds, and clouds in an area.
Factors That Affect Temperature The main factors that influence temperature are: • latitude • Altitude • distance from large bodies of water • ocean currents.
Earth has three main temperature zones: • Tropical zone – area near the equator • Polar zones – near the poles • Temperate zones – between the tropical and the polar zones
Distance From Large Bodies of Water: • Marine climates • Continental climates
Many marine climates are influenced by ocean currents, stream of water within the oceans that move in regular patterns.
The main factors that affect precipitation are prevailing winds and the presence of mountains. • Prevailing winds – the movement of large air masses • Mountains • Windward – the side of a mountain the oncoming wind hits • Leeward – downward side of the mountain in the rain shadow
Microclimates • A small area with specific climate conditions may have its own microclimate.
Seasons Most places on Earth outside the tropics have four seasons: • Winter • Spring • Summer • Fall
Tilted Axis • The seasons are caused by the tilt of Earth’s axis as Earth travels around the sun.
Climate Regions Scientists classify climates according to two major factors: • temperature • precipitation
There are five main climate regions: • Tropical rainy • Tropical wet – rain forests where plenty of rain falls all year round • Tropical wet and dry – savannas are tropical grasslands • Dry • Arid – deserts get less than 25 cm of rain each year • Semiarid – steppe (also known as grassland or prairie) • Temperate marine • Marine west coast • Mediterranean • Humid subtropical – climates are wet and warm, but not as constantly hot as the tropics • Temperate continental • Humid continental • Subartic – climates lie north of the humid continental climates • Polar • Ice cap • Tundra – climate region stretches across northern Alaska, Canada, & Russia • Highlands
Climate Regions Fairbanks Yakutsk Moscow Winnepeg London Seattle Istanbul Portland Beijing Chicago Rome Tokyo Tehran Atlanta Los Angeles Cairo Miami Calcutta Mexico City Bangkok Caracas Addis Ababa Lagos Nairobi Manaus Jakarta Lima Lusaka Rio de Janeiro Perth Sydney Santiago Cape Town Buenos Aires
Climate Regions TemperateContinental TropicalRainy ClimateRegions Dry include TemperateMarine Polar
In studying ancient climates, scientists follow an important principle: If plants or animals today need certain conditions to live, then similar plants and animals in the past also required those conditions. During each ice age, huge sheets of ice called glaciers covered large parts of Earth’s surface.
Possible explanations for major climate changes include: • variations in the position of Earth relative to the sun • changes in the sun’s energy output • Sunspots – dark cooler regions on the surface of the sun – linked to climate change • the movement of continents
Climate Change • What is it like inside a car that has been sitting in the sun? • Why was it so hot inside the car? • List factors that make the inside of the car so hot. • How might car windows and Earth’s atmosphere be similar?
The Greenhouse Effect and Global Warming Greenhouse gases – gases in the atmosphere that trap solar energy Human activities that add greenhouse gases to the atmosphere may be warming Earth’s atmosphere. Global warming – a gradual increase in the temperature of Earth’s atmosphere.
Ozone Depletion Chemicals produced by humans have been damaging the ozone layer. Chlorofluorocarbons – CFCs – the main the cause of ozone depletion are these groups of chlorine compounds.