Unit 6 Notes Flashcards
Why has absorption of longwave radiation increased?
The concentration of greenhouse gases in the atmosphere has increased.
How much have global average temperatures increased by since 1880?
Over 1 degree.
What are the sources of anthropogenic greenhouse gases?
Carbon Dioxide, Methane, Nitrous Oxide.
Which gas is responsible for 85% of Anthropogenic global warming?
Carbon Dioxide.
What % of methane emissions come from human activities?
60%.
What % of Nitrous oxide comes from human activities?
40%.
How much more potent is Nitrous oxide than C02?
290x.
Which latitudes have experiences the greatest level of warming of climate?
Above 60 degrees N - Polar/Tundra environments.
Why have Arctic areas experienced faster temperature increase?
The albedo effect - As ice starts to melt due to increased temperatures, more radiation is absorbed, due to less light coloured surfaces. Tundra - Permafrost thawing.
Which product has caused 5% of all man made climate change?
Cement.
How much Carbon dioxide is produced for every kg of beef produced?
60kg.
Which other products are also harmful for the world?
Rice, Peas.
Which biome is the most susceptible from global warming?
Tundra - Permafrost thaws, releases C02 previously stored in soil. It makes tundra a source not a sink of greenhouse gas emissions. The soil converts carbon into carbon dioxide.
What has happened to the extent of sea cover between 1981 and 2010?
The amount of sea ice has reduced from 7 million sq. km in 1981 to 3.8 million in 2020 - A fall of over 46%.
What is the impact of climate change on tundra species?
The polar bear was officially listed as threatened in 2008, as they require sea ice to hunt for seals. The lack of sea ice drives the bears to shore before they have built.
What % of the tundra biome is estimated to disappear by 2100?
77%, as Pine forests will shift northwards by up to 500km.
What are the impacts of the Pine forest moving northwards?
We lose many habitats, with a collapse of ecosystems, replaced by boreal forest. Animals could pass on diseases.
What is happening to Caribou rates in NW Canada?
They’re declining in all areas of Canada, increasing only in Porcupine. They no longer exist in Nunavut. Most have over a 90% decrease.
What are the main climate tipping points in the Arctic?
Ocean current changes, Ice Albedo feedback mechanism, Methane release.
How are Ocean current changes a tipping point?
Cold, salty water is produced in the North Atlantic, as the North Atlantic drift flows northwards. When ice sheets melt, they release freshwater into the Atlantic. This makes ocean less salty and less dense, slowing ocean circulation.
How is the Ice Albedo feedback mechanism a tipping point?
Once melted, sea ice is replaced by darker ocean, which has a lower albedo, absorbs insolation, warming the ocean more quickly.
How is Methane release a tipping point?
A significant increase in the concentration of Methane will rapidly increase global atmospheric temperatures.
How does methane affect permafrost?
Permafrost contains vast amounts of frozen organic material. Permafrost thawing means frozen organic matter begins to decay.
What are Methane hydrates?
Stored organic deposits within the sub-sea permafrost on the Arctic continental shelf.