+ YEAR 10 EARTH AND SPACE SCIENCE (ESS)

+ EARTH & SPACE SCIENCE 2 parts to the unit: EARTH – Global systems & SPACE – Origins of the universe We’re going to do the Space part first

+ UNIT REQUIREMENTS Star quiz Planetarium Excursion Assignment Orbits Experiment – How do planets move? Greenhouse Experiment Report Carbon Cycle Diagrams Great Barrier Reef Video (on Thursday) (due Thursday)

+ EARTH The Greenhouse Effect The Carbon Cycle Global warming – effects of deforestation Global warming – impact on arctic ecosystems

+ THE GREENHOUSE EFFECT Radiation enters the Earth’s atmosphere This provides warmth and light The short wave radiation can be reflected back into the atmosphere. However, the long-wave radiation gets trapped by the gases in our atmosphere and cannot escape. It returns back to the surface to continue warming. Greenhouses gases (like CO 2 ) enhance this effect.

+ THE GREENHOUSE EFFECT

+

+ THE GREENHOUSE GASES Carbon dioxide (CO 2 ) Methane (CH 4 ) Nitrous oxide (N 2 O)

+ THE GREENHOUSE GASES

+ THE GREENHOUSE EFFECT 1. Depletion of ozone layer letting in more ultra violet light (UV). 2. Build up of greenhouse gases keeps more reflected radiation in

+ THE CARBON CYCLE

+ The carbon cycle includes: Photosynthesis Cell respiration Combustion Fossilisation

+ THE CARBON CYCLE Photosynthesis removes CO 2 from the atmosphere Cell respiration, combustion and fossilisation all lead to an increase in levels of CO 2 Human impact is increasing the release of CO 2 into the environment

+ GLOBAL WARMING Photosynthesis in plants More trees - more CO 2 is taken from the atmosphere Less trees (deforestation) – less CO 2 removed from the atmosphere  increased greenhouse gases  global warming

+ GLOBAL WARMING Decomposition and fossil fuels Decay of living things releases CO 2 Dead material forms fossil fuels (coal, oil and natural gas) which release CO 2 when burned It is the combustion of fossil fuels in factories, cars, etc that can lead to carbon emissions and possible global warming.

+ GLOBAL WARMING Global temperatures have risen ~1-4 0 C: More hot days, fewer cold days, Increased rainfall in NE of Australia, decrease rainfall in the south More bushfires and destructive tropical cyclones

+ GLOBAL WARMING The trends in atmospheric gases are studied as indicators of potential climate change. The analysis of CO 2 trends is complex. eg. there are seasonal fluctuations in levels of atmospheric CO 2 Data taken from Vostok, Antarctica

+ GLOBAL WARMING

+ Long-term Trends: CO 2 levels fluctuate with ice ages and warm ages Short-term Trends: CO 2 levels are higher than any time in last 400,000 years (and are still rising)

+ GLOBAL WARMING Sea levels have risen: Increased 10-20cm last 100 years Further rises due to: Warming ocean water and resulting thermal expansion Melting of glaciers and polar ice caps

+ GLOBAL WARMING Permafrost is thawing: Carbon locked in the permafrost will be released Collapse of buildings and coastal cities Huge impact on Arctic and Antarctic ecosystems

+ GLOBAL WARMING IN THE ARCTIC

+ The average temp in the Arctic region is rising at twice the speed of the rest of the world. The polar cap is shrinking as a result. The snow and ice cover the Arctic reflects much of the Earth’s radiation. When this melts, the Arctic will absorb more heat and warm up even faster! This may also release CO 2 stored in ocean (increasing warming).

+ GLOBAL WARMING IN THE ARCTIC D iminished snow cover and permafrost I ncreased decomposition of detritus and burning of fuels (once trapped in permafrost) E xpansion of ranges of habitats available to temperate species (loss of tundra) I ncreased success of pest species and pathogens (leads to extinction of native species) C hanged behaviours of native species (e.g. migration, hibernation, birth cycles) E xtinction and loss of biodiversity

China and US agree on ambitious greenhouse gas emissions targets Updated 13 Nov 2014, 12:24amThu 13 Nov 2014, 12:24am China and the United States have agreed on a set of ambitious greenhouse gas emission targets, with Beijing setting a goal for its emissions to peak "around 2030". It is the first time China, the world's biggest polluter, has set a date for its emissions to stop increasing, and the White House said China would "try to peak early". At the same time the US set a goal to cut its own emissions of the gases blamed for climate change by per cent from 2005 levels by gas-emissions-targets/