Climate Change

What is climate change?

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years.  It may be a change in average weather conditions, or in the distribution of weather around the average conditions (i.e., more or fewer extreme weather events).

 

Climate change is caused by factors that include oceanic processes (such as oceanic circulation), variations in solar radiation received by Earth, plate tectonics and volcanic eruptions, and human-induced alterations of the natural world; these latter effects are currently causing global warming, and "climate change" is often used to describe human-specific impacts.

Global Warming

What is Global Warming?

Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. 

Warming of the climate system is unequivocal, and scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation. These findings are recognized by the national science academies of all major industrialized nations.

global mean land-ocean temperature index (anomaly)
Global mean land-ocean temperature index (anomaly), 1880 to present, the base period 1951-1980. The black line is the annual mean and the red line is the five-year running mean. The green bars show uncertainty estimates. From Wikicommons CC-BY-SA

The Greenhouse Effect

The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.

Flows of energy between outer space, the atmosphere, and the Earth's surface.
Flows of energy between outer space, the atmosphere, and the Earth's surface, and shows how these flows combine to trap heat near the surface and create the greenhouse effect. From Wikicommons CC-BY-SA, http://en.wikipedia.org/wiki/Greenhouse_effect

The impact of climate change on coastal Australian waters

Climate change will impact on several areas of importance in the Australian coastal regions.   The Australia government have published a report on the risks of climate change. The report presents the findings of the first pass national assessment of the risks of climate change for the whole of Australia's coast.

 

How climate change will impact on the marine environment are summarized below:

Increased Water Temperature

Southward migration of tropical and temperate species.  Increased frequency of coral bleaching episodes. Declining kelp forests off eastern Tasmania (Edyvane 2003; Edgar et al. 2005). 

Ocean chemistry (acidity)

Increased CO2 absorption by the ocean decreases  pH of the ocean and reduces availability of calcium carbonate which may impair the survival of organisms with calcium carbonate shells.

Ocean Circulation and Overturning

Changes to larval transport and upwelling regions and subsequent changes to productivity.

Increased Oceanic Sratification

Reduced overturning and nutrient cycling

Cloud Cover and Solar Radiance

Changes in the light supply to the ocean surface with influence on productivity. Increased storminess Increased turbidity, destruction of marine habitat  such as coral reefs during extreme events.

Sea Level Rise

Potential loss of mangrove forests and nursery  grounds for marine species.

Resources:

Climate Change the risks to Australias coast, on-line at:http://www.climatechange.gov.au/~/media/publications/coastline/cc-risks-full-report.pdf

 

What is climate change? modified from http://en.wikipedia.org/wiki/Climate_change, licenced under Wikicommons, Creative Commons Attribution-ShareAlike 3.0 Unported License (“CC BY-SA”).

 

What is Glodal Warming? modified from http://en.wikipedia.org/wiki/Global_warming , licenced under Wikicommons, Creative Commons Attribution-ShareAlike 3.0 Unported License (“CC BY-SA”).

 

Greenhouse Effect modified from http://en.wikipedia.org/wiki/Greenhouse_effect , licenced under Wikicommons, Creative Commons Attribution-ShareAlike 3.0 Unported License (“CC BY-SA”).

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Marine Science facts

  •  Irukandji jelly fish, with just a brush of venom leaves almost no mark. But after about a half hour you develop Irukandji syndrome, a debilitating mix of nausea, vomiting, severe pain, difficulty breathing, drenching sweating and sense of impending doom. You get so sick that your biggest worry is that you’re not going to die

 

  • Half the Oxygen we breath is produced in the Ocean

 

  • The most remote point in the oceans is called Point Nemo

 

  • The Pacific, Atlantic, and Indian oceans are known as the three major oceans.