2 Key terms Key term Definition Climate Change Long-term changes in temperature and precipitationDeforestationThe chopping down and removal of trees to clear and area of forestEcosystemsA community of plants and animals that interact with each other and their physical environmentEnhanced Greenhouse EffectThe increased greenhouse effect resulting from human action (emission of greenhouse gases) and leading to global warmingGeological Climate EventsClimate changes that result from major geological events such as volcanic eruptionsGlobal WarmingA trend whereby global temperatures rise over time, linked in modern times with the human production of greenhouse gasesGreenhouse gasesThose gases in the atmosphere that absorb outgoing radiation, hence increasing the temperature of the atmosphere
3 Key terms Key term Definition Ice Age A period in the earth’s past when the polar ice caps were much larger than todayLittle ice AgeA period of slight global cooling that lasted from around the mid- 15th Century to the mid-19th CenturyMega fauna‘Big animals’ which mostly weighed over 40kg e.g. Woolly mammoth and sabre-tooth catNatural causesProcesses and forces that are not controlled by humansOrbital ChangesChanges in the pathway of the Earth around the sun and the tilt on its axisQuaternary PeriodThe most recent geological period of the Earth’s historySolar OutputThe energy emitted from the sunStratosphereLayer of air 10-50km about the Earth’s surface
4 Key terms Key term Definition Food Chains Plants and animals are linked together and dependence on each other for foodExtinctionSpecies of plant or animal dying out completely, so none surviveDesertificationGradual change of the land into desertWeathershort term, day to day changes in the atmosphere.Climatethe average weather conditions over 30 years.Interglacialswarm periods between ice agesGlacialscold periods or ice ages. Ice sheets approx m thick extended across the northern hemisphere.Air massA huge body of air with uniform temperature and humidity.
5 Key facts: Climate graphs You must be familiar with reading climate graphs ...practise!Read rainfall scale from hereRead temperature scale from herePlymouth, UKoCmmName months!
6 Key facts: The UK climate UK (MEDC)ScotlandWalesEngland
7 Key facts: The UK climate UK (MEDC)What controls the UK climate?A lot to do with ‘air masses’.Air masses are huge blocks of air. They can be damp or dry, warm or cold, depending on where they came from and over what type of surface they have travelled.For example, an air mass that has travelled over the sea will increase its moisture content and be more likely to produce rainy weather.
8 Key facts: Past temperatures have always fluctuated Climate has changed in the past through natural causes on timescales ranging from hundreds to millions of years.
10 Key facts: Recording past climate How do we know climate was different in the past?Fossils of animals and plants that no longer live in the UK.Landforms left by glaciersSamples from ice sheets in Antarctica. Ice sheets are made up of layers of ice, a layer for each year. Trapped in the ice sheets are air bubbles. Climatologists study the CO2 levels to reconstruct past climates.How do we know climate has changed in the more recent past?Old photos, paintingsDiariesNewspapersRecorded dates of blossom and migration of birds.
11 Natural causes of climate change TheoryFactsEruption theory:Big volcanic eruptions can change the Earth's climate. Small eruptions have no effect, it has to be very large and explosive. Volcanic eruptions can produce ash and sulphur dioxide Gas. If the ash and gas rise high enough they will be spread about the Earth's stratosphere by high level winds. The blanket of ash and gas that this creates will stop some sunlight reaching the Earth's surface. Instead, the sunlight is reflected off this blanket back into space. This cools the planet and lowers the average temperature.Sunspot theory:Sunspots (black areas on the sun) were first recorded over 2000 years ago. Sometimes there are lots of these and at other times they disappear. Even though these spots are dark, they tell us that the Sun is more active than usual. Lots of spots mean more solar energy is being fired out from the Sun towards Earth. Cooler periods, such as the Little Ice Age, and warmer periods, such as the Medieval Warm Period, may have been caused by changes in sunspot activity.Orbit theory:Over very long timescales, there have been big changes in climate. Glacial periods were 5-6 degrees colder than today and interglacial periods were 2-3 degrees warmer than today. Such big changes need a big cause.Over long periods of time the Earth's orbit changes:The Earth's orbit is sometimes circular, and sometimes more of an ellipse (oval).The Earth's axis tilts. Sometimes it is more upright, and sometimes it is more on its side.The Earth's axis wobbles, like a spinning top about to fall over.These changes alter the amount of sunlight the Earth receives and they affect where sunlight falls on the Earth's surface. Over thousands of years these changes could start or end ice ages. These changes are called MILANKOVITCH cycles.
12 Impact of past climate change ‘Little Ice Age’A period of significant cooling 300 years agoIt had a negative impact on agriculture (farming), people & ecosystems.
13 Impact of the ‘Little Ice Age’: On people and the environment ECONOMIC +VEECONOMIC -VEHEALTHENVIRONMENTFARMINGEnglish fisherman found herring normally located in the waters off Norway.Increasing grain prices and lower wine productionCool, wet summers led to outbreaks of St. Anthony's Fire illnessBeech trees, were replaced first by oak and then by pine.Wheat and oats did not ripen so the harvests failedIncrease in deep-sea fishing helped to build the maritime populationMany farmsteads were destroyed, resulting in less taxMalaria in several parts of EnglandCold and rain occurred in the spring and summer of 1315Farms high on hillsides were abandonedCod fishing greatly decreased, as the cod moved farther south.Great Famine lasted 8 yearsIn the Alps, valley glaciers grew in the colder climateThey had to change their crops from wheat to potatoesAdvancing glaciers closed the gold mines.10-20% of farmers died from hunger
14 Impact of past climate change .....Focus on agriculture.Western Europe experienced a general cooling of the climate between and a very cold climate betweenDuring the coldest times, England's growing season was shortened by 1-2 months compared to today.Unlike seeds today, back then the seeds could not survive the extreme cold or warmth, wetness or dryness.Price of wheat went up dramatically as it became more difficult to grow and get hold of.Climate changes had a much greater impact on agricultural output in the past.One of the worst famines in the seventeenth century occurred in France due to the failed harvest of Millions of people in France and surrounding countries were killed.In Norway, many farms located at higher latitudes were abandoned for better land in the valleys.
15 How were ecosystems affected by climate change in the past? The dinosaur extinction was possibly caused by a massive asteroid hitting Mexico and a huge volcano in India combining: dust, ash, gas go up into the stratosphere which blocks the sun out which cools the climate so plants don’t grow so dinosaurs have no food……which has a knock on effect through the food chain.Megafauna extinction – big animals like the woolly mammoth and sabre-toothed tiger. The climate was warming so they had to find new areas to live where the climate suited them. This disrupted food chains. Humans also hunted them to extinction.
16 Mega fauna extinction This caused temperatures to rise, ice to melt andglaciers to retreat.The retreating glaciersmeant there was lesswater available for theplants & animals.The ice age(Pleistocene) periodfinished around10,000 years ago.The lack of herbivoresmeant carnivorousanimals began to die asthey had less prey.The lack of plants meantherbivores (vegetarian)animals began to die.The lack of water & risein temperature meantlots of plants died as theycould not adapt.The overall change inclimate caused a bigchange in the food chain,which meant many animalsbecame extinct.Other theories suggestsome animals becameextinct because theywere hunted by humans.
17 Climate change and humans The main greenhouse gasses
18 Greenhouse gasses and temperature “Describe the graph”1880:Global temperature = -0.4oFCarbon Dioxide = 300ppmFluctuating, but general increase of both global temperature and CO2 between Then a much faster rate of growth for both factors, until:2000:Global temperature = 1oFCarbon Dioxide = 380ppmThere is a direct link between the amount of carbon dioxide in the atmosphere and temperature.
20 How Does the Greenhouse Effect Work? Greenhouse gases (CO2 from the burning of fossil fuels, deforestation, Methane from paddy fields etc....) trap heat from leaving the atmosphere and re-radiate that heat back down to earth.The greater the concentration of greenhouse gases, the more heat is trapped and the warmer earth becomes.We need the NATURAL greenhouse effect – it makes the planet 16 degrees warmer. Without it the earth would be too cold for us to survive.The extra greenhouse gases produces by humans burning fossil fuels power stations, transport, industry, homes.
21 Greenhouse gases: Change over time Since pre-industrial times, atmospheric concentrations of greenhouse gases have grown significantly:countries become more industrialisedpeople become consumers of energy and goodsBecome bigger producers of air pollution (through the burning of fossil fuels)Most greenhouse gases are produced by developed countries – the EU, USA, Japan.
22 Greenhouse gases: Change over time The USA produce the largest amounts of CO2 each year.The world’s current level of CO2 is increasing at a rate of 200x faster than at any time in the past million years.Rates of methane have also doubled since the 1800s due to the growing world’s population demanding an increasing amount of cows for meat.Emerging powers such as China and India are now in line with older polluters such as USA and Europe due to the take off of their development.China is now the world’s largest single polluter.
24 World C02 emissions:Highest C02 emissions = North America, Europe, Japan, UAE, China (predominantly MEDCs and NICs)Lowest C02 emissions = South America, Africa, Russia (predominantly LEDCs)
25 World C02 emissions:China emits more CO2 than the US and Canada put together - up by 171% since the year 2000.India is now the world's third biggest emitter of CO2 - pushing Russia into fourth place.The biggest decrease from is Ukraine - down 28% in recent years. The biggest increase is the Cook Islands - up 66.7% since 2000.But that is only one way to look at the data - and it doesn't take account how many people live in each country. If you look at per capita emissions, a different picture emerges where:Some of the world's smallest countries and islands emit the most per person - the highest being Gibraltar with 152 tonnes per person.The US is still number one in terms of per capita emissions among the big economies - with 18 tonnes emitted per person.China, by contrast, emits under six tonnes per person, India only 1.3For comparison, the whole world emits 4.49 tonnes per person (average).
26 World C02 emissions: Reasons for variations in global emissions MEDCLEDCTransport – more cars per capita, bigger cars, more air travel.Transport – fewer cars, less air travel, greater use of public transport.Energy supply – more electrical goods needing energy i.e. Televisions, computers, hairdryers, games consolesEnergy supply – more traditional fuels used, lower demand per person, fewer electrical appliances within households.Business and industry – greater number of industries, bigger outputs, offices.Business and industry – more primary and secondary industries.Homes – larger homes, central heading/air conditioning, more energy intensive construction.Homes – smaller homes, often traditional building methods with less environmental impact.
27 Effects of the environment Effects on peopleEffects of the environment
28 Predicting the future: Why is it hard to predict future levels of greenhouse gases?We don’t know if people will change their lifestyles and recycle more, or use more public transport.We don’t know if we will continue to use fossil fuels, or change to cleaner energy like wind or solarWe don’t know what the world’s future population will be
29 Climate change will have positive & negative impacts on people, the environment and countries economies.Case studies!Developing countries will be affected more negatively than developed countries.
30 How might a developed country be affected by climate change? UKMore extreme weatherSea level riseWarmerUK (MEDC)
31 How might a developed country be affected by climate change? UK (MEDC)WarmerSea- level riseMore extreme weather
32 Future UK climate UK (MEDC) Overall UK summers and winters will be warmer.Temperature on average will rise by 4°C by 2080.In the summer heat waves will be become more common as temperatures reach 40°CRainfall in the summer is expected to decrease and as a result we will suffer from more droughts.Winters will bring less snow and more rain.We will also receive more severe storms.
33 How might a developing country be affected by climate change? Egypt (LEDC)A developing countryLow greenhouse gas emissions – 2.6 tonnes per person per year (world average = 6.8)Produce less than 1% all green house gases.99% of Egypt’s people live in 5% land area as so much is desert.Average rainfall = less than 10mm/yrThe River Nile is an important water supply.
34 How might a developing country be affected by climate change? Egypt (LEDC)With Global Warming…If sea levels rise 50cm, 1/3 of the city of Alexandria would be under water.10% Nile Delta would flood 7 million people would have to leave their homes farming would be hit there would be less food famine.Less and more unreliable rainfall water shortages.DesertificationHeat waves illness and death.Malaria increase.Water Wars?86% of the Nile’s water starts it’s journey in Ethiopia.Uganda, Sudan and Ethiopia are all building huge dams for Hydro Electric Power (HEP).This could have a serious impact on the amount of water reaching Egypt This could lead to conflict and war.Egypt has a debt of $30 billion. It may not be able to cope with the impacts of global warming.
36 Video revision: What are air masses? Antarctic Ice reveals Climate HistoryDinosaurs ExtinctionEvidence for global warming - polar ice capsClimate change dangersGlobal Warming - None Like It Hot!BBC climate experimentClimate Change and the future of weatherEgypt struggles with climate change
37 Past GCSE questions: AOutline one reason why sea level is expected to rise in the future (2 marks)Describe two impact of melting ice sheets on the environment (2 marks)Describe one impact of a short term past climate change on a) People b) the environment (4 marks)Explain how natural events can cause climate change. (4 marks)Describe two natural cause of climate change. (4 marks)Explain how human activity is leading to climate change. (4 marks)
38 Past GCSE questions: BDescribe how two human activities can contribute to climate change. (2 marks)Give two reasons why developing countries often produce less carbon dioxide than developed countries (2 marks)Explain the possible economic (money) impacts of climate change on a named country. (4 marks)Describe one way in which climate change might make people poorer (2 marks)For a named developing country, explain why climate change is likely to have a large impact on its people. (6 marks)
39 Past GCSE questions: CFor a named developing country, explain how climate change is likely to have a large impact on its economy. (6 marks)For a named country, suggest one possible impact of higher global temperatures. (2 marks)State two possible impacts of climate change in the UK (2 marks)Explain how the future climate of the UK is likely to be affected by global climate change (6 marks)Describe how climate change in the past, such as the Little Ice Age, affected people and ecosystems. (4marks).Describe how colder periods, such as the Little Ice Age, affected farming. (2 marks)