Evidence of Climate change 6.4 – Changing Environments

Climate change

How human activity contributes to global warming Clear forests for agriculture Decreases the amount of carbon being absorbed by plants Increases the amount of the greenhouse gas methane in our atmosphere from animal wastes Burning Fossil fuels Increases the amount of carbon dioxide in the atmosphere Increases the Earths temperature Melt polar ice caps Less sun is being reflected Oceans warm faster Sea levels rise Coastal populations are threated with flooding

Evidence of climate change

Rising air temperature There is a direct correlation between the increase in surface temperatures and the amount of carbon dioxide in our atmosphere This trend shows that as the amount of CO2 increases over time, as does average surface temperatures

Rising sea level Between 1993 and 2005 sea level rose, on average, 3mm per year Due to an increase in melting ice and thermal expansion as the ocean absorbs excess energy.

Decrease in arctic ice Since 1979, the Arctic Sea ice shrunk on average 2.7% per decade, with larger decreases in the summer of about 7.4% Arctic summer sea ice has decreased by roughly 34% since 1979

The excess amount of CO2 in the atmosphere accelerates the greenhouse effect trapping more heat near the surface This causes polar ice caps to melt thus less sunlight they are able to reflect Therefore making the oceans warm even faster which increases the rise of sea levels

Extreme weather Extreme weather events dominated the 2012/2013 Australian summer, including record-breaking heat, severe bushfires, extreme rainfall and damaging flooding. Extreme heatwaves and catastrophic bushfire conditions during the Angry Summer were made worse by climate change. All extreme weather events are now occurring in a climate system that is warmer and moister than it was 50 years ago. This influences the nature, impact and intensity of extreme weather events. It is highly likely that extreme hot weather will become even more frequent and severe in Australia and around the globe over the coming decades

2012-2013 ANGRY SUMMER

click here for full article This is happening now! click here for full article This March (2016) was the hottest on record for Australia, according to new data released by the Bureau of Meteorology (BoM). The national mean temperature was 1.7°C above the historical March average, exceeding the previous record of 1.67°C set in 1986.

5 key findings – extreme weather Heatwaves and hot days, drought and rainfall deficiency, and bushfires dominated the 2013/2014 summer. Climate change is already increasing the intensity and frequency of extreme weather events in Australia. Many of our largest population centres stand out as being at increased risk from extreme weather events, including heatwaves, drought and bushfires. The impacts of extreme weather events on people, property, communities and the environment are serious and costly. Limiting the increase in extreme weather activity requires urgent and deep reductions in the emissions of greenhouse gases. The decisions we make this decade will largely determine the severity of climate change and its influence on extreme events for our grandchildren. This is the critical decade.

Changing of rainfall patterns higher temperatures increased evaporation more water vapour in atmosphere more precipitation (rainfall, hail, snow)

Over the last few years the east coast of Australia has experienced a number of intense rainfall events This triggers large floods that have cost lives, damaged property, inundated ecosystems and caused significant dislocation to local and regional communities.

Who will survive? Not all plants and animals die out when the temperature changes. When the climate warms, species move towards the poles. During a period of cooling, they move towards the equator. Urban development and clearing land for agriculture have destroyed some natural ecosystems and divided others into small fragments. This makes it more difficult for organisms to move away from areas that are no longer suitable Climate change and the destruction of ecosystems by human activity has led to a decrease in biodiversity

Tolerance range For each abiotic factor (eg pH, salinity, temperature) organisms have a range of tolerance in which they can survive Some organisms are a lot more sensitive to change than others therefore having a small optimum range

Tolerance range Optimum range Tolerance range  preferred niche where organism numbers are most abundant Tolerance range  organisms do not survive when environmental conditions are outside the tolerance range Zone of physiological stress  These environmental conditions are not preferred however the organism can survive Zone of death  Organisms can not survive in these environmental conditions and die

Example – effects of temperature on trout

Example – effects of temperature or coral Coral have a small optimum range to temperature therefore a small increase puts these organisms under high physiological stress Corals are very sensitive to small changes in temperature. An increase in temperature of only 1 – 1.5◦C above the summer average maximum can cause extensive coral bleaching

coral bleaching The health of coral reefs depend on the symbiotic relationship between the coral and zooxanthellae

click here for full article In the media click here for full article

See how your world will change due to global temperature increases Global warming, caused by carbon pollution from burning fossil fuels like coal, gas and oil, is having a huge impact on the world around us. It isn’t just affecting the polar ice- caps, it’s impacting the people and places we love. Interactive Activity http://earthhour.org.au/climatefuture/default.aspx

How are your actions influencing our planet? The following activity will show you how your everyday choices contribute to climate change. Interactive Activity http://www.gamesolo.com/games/ecoego.swf

Promoting awareness

How can you reduce co2 emissions We need to urgently invest in clean energy sources and take other measures to reduce emissions of greenhouse gases