Climate and Change Unit 1 revision session

Defining terms... Weather – the day-to-day condition of the atmosphere Climate – the average weather over 30 years Interglacial – warm periods in the earth’s climate Glacial – cooler periods in the earth’s climate

What do the graphs tell us?

How do we know climate changes? Fossilised plants, animals and pollen Landforms Ice sheet samples (ice cores) Old photographs/paintings Diaries, books and newspapers Recorded dates of regular events e.g. Harvests, tree blossom, migrations etc

Ice Age Glacials last about 80, ,000 years Some glacials were so cold the Earth plunged into an ice age The last ice age was30,000-10, 000 years ago Ice m thick, it caused The Earth’s crust to sag, sea level fell by 100m

How Climate has changes in the past Eruption TheorySunspot TheoryOrbital Theory gzone/clips/volcanoes-and- global-climate/1479.html

Scales of Climate Change s-of-climate-change/1491.html Description: A look at climate change over a range of timescales. Long term changes include changes in the suns output, the orbit of the earth, the tilt of the earth's axis and wobble in the earth's axis of rotation. It ends with a look at how changes in albedo and increased urbanisation and industry have influenced global warming through increased pollution.

Changing the Atmosphere

Contributors to the Enhanced Greenhouse Effect

Climate has changed in the Past Greenland Vikings Medieval warm period meant: Greenland much warmer: good trade links, farms and population The Little Ice Age meant that life became harsh: – Sea ice prevented trade – Less food caught due to shorter summer = starvation – Livestock could not be supported =... The Little Ice Age The Little Ice Age brought a halt to prosperous Europe Longer winters Colder More Rain Failing crops PEOPLE ADAPTED!

Climate and Ecosystems Climate Sunlight Precipitation Plants Air Carnivores Herbivores Water Soil Rock Ecosystems break down as climate changes Mass extinction: animals/plants completely die out Megafauna Extinction: Climate change & humans

Emissions

Impact

The Future? Shrinking ice caps Rising sea levels Increasing global temperatures Floods Droughts Heatwaves Storms Hurricanes

In summary... CARBON DIOXIDE is a greenhouse GAS. These gases in the ATMOSPHERE keep the planet comfortably WARM. Human activities are producing more greenhouse gases which POLLUTE the atmosphere. This is causing the ENHANCED GREENHOUSE EFFECT and seems to be leading to GLOBAL WARMING.

Impacts of a warmer UK Advantages (benefits/pros) Heating and gritting costs could fall in winter More UK-based holidays Fewer deaths of the old and infirm during winter New crops mean new opportunities More land could be farmed Disadvantages (costs/cons) More common drought and water shortage (summer) More illness e.g. Heat stroke and skin cancer Melting road surfaces and buckling railway lines Changes in crops grown Extinction of some plants and animals

UK Summary

Acting on climate change Stern Review 2006 – ‘spend now or pay later’ Kyoto Protocol 1997 – international agreements to reduce carbon emissions Agenda 21 – Act local think global

Egypt Temperature rises of 8c by 2080 Less and more unreliable rainfall The spread of the Sahara Desert (Desertification) onto areas of farmland. Falling crop yields as temperatures rise and water shortages increase. Heatwaves bring more illness and death The spread of diseases like malaria.

Wider Impacts Example: EGYPT