Planet Paper 2 Module 3 Monday 02 March 2020 What evidence do we have for climate change Focus Task How has the climate changed overtime Key Words Task Identify what is meant by the key words ID: 1022560
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1. Environmental Threats to Our PlanetPaper 2, Module 3
2. Monday, 02 March 2020What evidence do we have for climate change?Focus TaskHow has the climate changed overtime?
3. Key WordsTask: Identify what is meant by the key words. Key WordDefinitionQuaternary PeriodIce AgeClimate ChangeInter-glacial Periods
4. Key WordsKey WordDefinitionQuaternary PeriodThe most recent geological period covering last 2.6 million years, which there were several cold and warm periods. Ice AgeA glacial episode characterised by lower than average global temperatures.Climate ChangeChanges in long-term temperature and precipitation patterns. It can be natural or linked to human activities.Inter-glacial PeriodsHistoric warming periods between glacial periods, where conditions were similar to today.
5. What is the Quaternary Period?The Earth is believed to be 4.55 billion years old. The period of time that stretches from 2.6 million years ago to the present day is called the Quaternary period. The entire Quaternary period is often called an ice age due to the presence of a permanent ice sheet on the continent of Antarctica.
6. Last 400,000 YearsThe human species evolved about 200,000 years agoTemperatures have remained relatively stable and warmer for longerInter-glacial episodes last approximately 10,000 years; ice retreats during these warmer intervalsGlacial episodes last approximately 100,000 years; thick ice expands, covering vast areas of continents
7. What evidence do we have for climate change?Evidence for past climate change can be gathered from a range of sources including:Global temperature dataIce coresTree rings Paintings and diaries
8. Ice CoresHow can ice cores be used as evidence for climate change?How is this a reliable method?How is this not a reliable method?Oxygen, carbon dioxide and methane in ice cores can help estimate past temperature (spanning 800,000 years) by comparing it against present levels. Scientists drill deep into the ice in the Antarctic and Greenland to extract ice that is thousands of years old. + The data is considered to be very reliable.Data only spans the last 800,000 years so it is difficult to compare beyond that.Ice cores are geographically limited.
9. Tree RingsHow can tree rings be used as evidence for climate change?How is this a reliable method?How is this not a reliable method?Each tree ring represents a year of growth. Narrow tree rings indicate cooler and drier past climate conditions.Wider tree rings indicate warmer and wetter past conditions. + Samples can be easily compared and dated.+ Can tell precisely when the tree ring was created. Some trees (birch and willow) can not be used due to their erratic growth cycle. Alder and pine trees are well known for missing out tree rings.
10. Paintings and DrawingsHow can paintings and drawings be used as evidence for climate change?How is this a reliable method?How is this not a reliable method?Diaries and written observations can suggest evidence of climate change at the time such as:Price increases of grain in Europe. Sea ice preventing ships from landing in Iceland. People emigrating due to crop failures.+ Provides a visual representation.Cave paintings are difficult to date accurately.- Personal accounts and art are subjective viewpoints.
11. Global Temperature DataHow can global temperature data be used as evidence for climate change?How is this a reliable method?How is this not a reliable method?NASA use over 1000 ground weather stations and satellite information to map global temperature. Average global temperatures have increased by 0.6°C since 1950 and 0.85°C since 1880.Weather stations are not evenly distributed (especially in Africa), so reliability could be questioned. Computer programmes are used to make the global temperature maps, but this does not make them reliable. Data only goes back to 1880.
12. Exam Question Describe how ice cores can be used as evidence of climate change. [2]
13. Mark Scheme2 x 1 (P) for description of how ice cores can be used as evidence of climate change. The layers of ice within the core build up over time and these can be dated to show past temperatures (1). The bubbles of trapped gases such as methane can be tested by scientists (1). Ice cores allow measurements of carbon dioxide to go further back in time (1).
14. Exam Question Describe the advantages and disadvantages of using paintings and drawings as evidence of climate change. [4]
15. Resources
16. Evidence of Climate Change EvidenceHow is it used?Advantages of methodDisadvantages of methodGlobal Temperature DataIce CoresPaintings and DrawingsTree Rings