Ocean Temperatures and Thermographs

Grade 6 Science unit 3 lesson 9 Effects of Ocean Temperatures and

Thermographs

What is a Thermograph?

• A Thermograph is a small bi-metallic strip used to measure temperature. The strip bends with changes in temperature. It records temperature on a revolving cylinder attached to it. A similar device is also used in medicine, and has other applications for detecting heat.

Thermographic Image under the Gateway Bridge

The Flow On Effect• Thermographs have shown

worldwide a rise in sea levels due to warming of the seas and melting of the polar ice caps

• Under the worst scenario, island nations, coastal cities and beaches alike would be threatened with obliteration.

• Groundwater aquifers could be polluted by salt water.

• Tunnels, harbours and coastal wetlands could be soaked with salt water.

Where could this lead?Eventually, if greenhouse warming continues, big changes could be in store for our planet.The continental shelves harbor huge amounts of stored methane, a potent greenhouse gas in its own right. If coastal waters warm enough, this methane could be released, causing greatly increased warming. Similarly, warming in the Arctic tundra could release vast stores of carbon dioxide, with similar effects.

Ice SheetsWhen ice cascades off land, such as an ice sheet, that increases the volume of water in the oceans adding to rising sea levels.The West Antarctic Ice Sheet holds 3 million cubic kilometers of fresh water. If it melted, sea level would rise 6 meters, and coastal cities would be underwater.

A Common Myth…do the Math

Ice shelves melt all the time, "calving" icebergs that, no matter how enormous, do not effect sea level. Because

Floating ice displacesthe same volume of wateras melted ice

Icebergs that formed from floating ice on Antarctica's vast ice shelves add no volume to the ocean.

Marine animals and Global Warming

Marine species affected by climate change include plankton - which forms the basis of marine food chains - corals, fish, polar bears, walruses, seals, sea lions, penguins, and seabirds.A further rise in temperature is predicted. Climate change could mean the end of many species which are already under stress from overfishing and habitat loss.

Key impacts of Climate Change

Coral Bleaching due to increased temperatures leads to coral death. What does that mean for the fish that live off and around that reef?

The Impacts of Climate Change

Extreme weather – more cyclones, more floods, more erosion and pollution of the sea bed.Fish “moving home” in response to warmer seas, thus changing local

ecosystems.

Lifestyle Changes

Rising temperatures can directly affect the metabolism, life cycle, and behaviour of marine species.

For many species, temperature serves as a cue for reproduction. Changes in sea temperature could affect their successful breeding.

Turtle Population

The number of male and female offspring is determined by temperature for marine turtles,as well as some fish and copepods (tiny shrimp-like animals on which many other marine animals feed).

Changing climate could therefore skew sex ratios and threaten population survival.

Acid Oceans

After absorbing a large proportion of the carbon dioxide released by human activities, the oceans are becoming acidic. If it weren’t for the oceans, the level of carbon dioxide in the atmosphere would be much higher.

Acid Oceans• Fish, squid, and other gilled

marine animals may find it harder to "breathe", as the dissolved oxygen essential for their life becomes difficult to extract as water becomes more acidic.

• Shellfish, crabs, lobsters, and corals may find it more difficult to build their calcium carbonate shells. In some areas, calcium carbonate shells may even start to dissolve.

Are You Getting the Picture?What will our oceans look like if we continue to disregard global warming and increased sea temperatures?Life on land will also change, with increased carbon dioxide causing a drop in nutrients in food that we eat.It is safe to say that the world will be much changed, and the climate and diversity of life on earth would be greatly impaired.

What Can We Do to Reverse the Flow?

• Small changes can affect the whole ecosystem and bring about real progress.

• In many agricultural areas in eastern Australia and southwest Western Australia more than 90% of native vegetation has been cleared.

• Protection and restoration of Australia's native vegetation needs to be a critical consideration in mitigating climate change.

Plant Native

• Native vegetation plays an important role in moderating climate because it is deep rooted, which leads to more moisture evaporating into the atmosphere over a longer period.

• This is then recycled into the environment as rainfall.

• Native vegetation also reflects less short-wave solar radiation into the atmosphere than crops, which keeps the surface temperature cooler and helps in cloud formation.

The Bigger Picture – A Climate Change Global Wishlist

1. Advocating a new international climate agreement – one that is just and legally binding.

2. Promote energy efficiency – the most rapid and cost-effective way to reduce CO2 emissions.

3. Promoting renewable energy sources – like wind, solar, and geothermal power.

4. Preventing greenhouse gas emissions from deforestation – currently responsible for 20% of all emissions.

5. Developing and promoting climate change adaptation strategies – to safeguard the most vulnerable people and the most exposed ecosystems.