Unit 7B Flashcards
Effects of Positive Radiative Forcing
-Energy imbalance means more of the outgoing infrared radiation is trapped in the lower atmosphere
-Leading to Climate Change
-Due to positive and negative feedbacks found in the ecosystems, there are changes in the structural and functional components of the environment in response:Severe Weather - Patterns and Occurrences
Biosphere – increase loss of species, change in distribution
Pedosphere/Lithosphere – Soil degradation and loss of production
Cryosphere (frozen water) and Hydrosphere – patterns in snow and ice melt; severe weather etc.
Climate Change
the change observed in long-term averages of daily weather for a region: precipitation, temperature, humidity, sunshine, wind velocity, fog, frost, and hail storms
Indicators of the Radiative Imbalance
- Increased humidity, air temperature near surface, temperature over oceans, sea level, ocean heat content, temperature over the land, sea surface temperature
- Decreased glaciers, snow cover, sea ice
Warming is the greatest is the Arctic- polar amplification associated with ice albedo effect
- Positive feedback system
- Resulted in a greater the 2 degree annual temperature and far greater than anywhere else on the planet
- Melt water from artic increase the volume of sea water, and increases salinity
- Permafrost soils-defrosted layer is active layer, making the soil slippery and is on the move, leads to erosion
- Arctic sea ice loss associated with increased temperatures
The (Arctic) Cryosphere
How Is it Changing?
- The cryosphere includes the solid water surfaces on Earth: snow, sea ice, glaciers, permafrost, ice sheets, and icebergs
- Affects Earth’s energy budget since these are highly reflective surfaces and contribute to negative forcing and enhance the ice albedo effect
- Accelerated melting and erosion of sea ice is amplifying a warming influence, contributing to further loss in a positive feedback process
- Sea Ice Loss
- Greenland land-base ice melt
- Permafrost soil loss
Climate Change Impacts Amplify Existing Risks and Create New Ones
Permafrost Melt – Carbon Emission (permafrost will no longer be a sink for carbon storage but a source!)
- Twice as much carbon is stored deep in permafrost soils as is present in the atmosphere
- Warming soils accelerates decomposition and potential for carbon release.
- Expect a positive feedback response contributing increasing amounts of CO2 and CH4 to the atmosphere!
Climate Change Impacts – Sea Level Rise
- Land based glacial ice melts could result in sea level rise
- Thermal expansion due to rising temperature
- Sea level has risen about 20 cm since 1900 and will continue with glacial ice melting
- US Geological Survey (June 2012) – Rates of sea level rise are increasing three-to-four times faster along portions of the U.S. Atlantic Coast than globally
- Check out – When Rising Seas Hit Home
- Flooding of coastal estuaries, wetlands, and coral reefs particularly important in biodiversity and productivity
- Beach and coastal shoreline erosion
- Salt water contamination of coastal aquifers
Climate Changes and Ocean Dynamics
The addition of freshwater due to melting glaciers and sea ice may reduce the density gradient between surface and deep waterswhich in turn would stall or stop the ocean circulation of the thermohaline gradient.
-Heat transfer to Europe would be lessened, cooling the continent.
Increasing amounts of carbon dioxide dissolve in ocean waters forming carbonic acid and changes in acidity.
With more acids, there is less calcium available for shell forming organisms and corals reefs – populations decline.
Warming waters are not able to hold as much gas and therefore unable to hold oxygen and carbon dioxide. This effects the oceans’ capacity to hold carbon as a sink.
And….slower thermohaline circulation will further reduce carbon storage.
Severe Weather
Expect changes in the frequency, intensity, and duration of extreme weather and climate events. Results may be an unprecedented number of extreme weather events (IPCC)
Fort McMurray in 2016 - $4 Billion in costs
Dealing with the mental health impacts alone are conservatively estimated to be $2.27 billion.
California Wildfires –loss of life and infrastructure $80+ billion to rebuild
Agriculture
-Productivity increases for some crops at higher latitudes while reductions in lower latitudes because warmer temperatures and droughts could result in crop failures.
-Increased irrigation demands on already stressed groundwater supplies and greater prevalence of soil salinization.
More pests, crop diseases, and weeds in warmer regions placing greater reliance on pesticide application.
Biodiversity
- Climate change is viewed as one of the greatest threats to biodiversity
- Rapid changes in climate challenge species to cope
- Habitat loss, distribution and migration of new species alter ecosystem dynamics and interactions.
- Range expansion of species seen as migrating northward and to higher altitudes in response to changes in climate
