BIOEE1610 Global Warming

• The expansion of water as it is heated (thermal expansion responsible for 50% of the rising sea levels)
• The melting of glaciers
• The melting of the floating Arctic ice sheet has little effect on sea levels. (same as ice melting in your drink) What we’re concerned about is the continental glaciers.

• Erosion of shorelines and barrier islands, climate refugees
• Higher water levels and increasing salinity in estuaries and coastal wetlands change the plant community

• General circulation models simulate the physical processes that determine Earth’s energy budget:
• Absorption and reflection of heat by the atmosphere
• The heating of land and ocean
• IR radiation given off by land and ocean
• Circulation of heat from the equator to the poles
• Ocean circulation
• Backcasting: comparing prediction about the past using data with actual data. GCM forecasts lose accuracy as the land under consideration gets smaller.
• Two assumptions are generally agree upon:
• Rainfall will increase in areas with high altitudes such as Eurasia and Canada
• Rainfall will decrease in subtropical and temperate areas that are already arid.

• Actions that directly decrease an environmental threat such as CO2 emissions.
• Increased energy efficiency and conservation (in buildings, heating, public transportation)
• Increased use of renewable resources (wind, solar, biofuels have net 0 carbon emissions since corn wood etc. pull CO2 from the atmosphere. However, there’s significant concern about the implications of biofuels on the global food supply)
• Nuclear energy
• Biostorage (actions that increase the storage and absorption of CO2) like planting trees or promoting agricultural practices like efficient fertilizer use that encourage carbon storage.
• Carbon capture storage technologies
• Climate engineering (perhaps)

• Adaptation techniques are important as not all nations will be affected equally. Additionally, the capacity to adapt to climate change is also not distributed equally.
• Switching to drought resistant crops in southwestern US, the Mediterranean, the Middle East or Sub-Saharan Africa.
• Water pricing, drip irrigation (efficient irrigation), turning salt water to fresh water
• Pumping systems, water walls, canals, water resistant construction in areas that are prone to water level rise and subsequent flooding, storms
• Wildfire management systems
• Effective systems to protect vulnerable populations from heat rise
• Restoration of natural ecosystems such as coral reefs, coastal wetlands, seagrass forests as natural buffers of waves has been considered as opposed to water walls as an adaptation technique.
• Legislation: carbon-cap and trade, carbon taxes

• 10 degrees.
• The current average is 15 degrees.
• A change of 5 degrees gave us an ice age.
• Predicted temperature increase until 2100 ranges between 1-4 degrees.
• Different scenarios (business as usual, sustainable world, today’s world) show different degrees of temperature increase.
• However, all scenarios include higher warming at higher latitudes and more warming over land than ocean.

• Increased rainfall in most tropics and higher latitudes.
• Decreasing rainfall and increasing drought in middle latitudes and semi-arid low latitudes.
• Resulting in changing climate and shifting biomes.
• Leading to water stress for millions of people.

• Increased damage from storms and floods.
• Sea level rise.
• Migration

• Large-scale extinctions
• Coral bleaching and loss of species dependant on coral reefs.
• Increases species range shifts and phenology changes.
• Increased wildfire risk. (due to changes in precipitation/moisture, higher temperatures)
• Carbon source/sink dynamics change. (hard to predict because they’re not in isolation)

• Algae and corals have a mutualistic relationship through which corals give algae protection and nutrients. In exchange, algae give corals oxygen and energy compounds & help remove wastes.
• Warm temperatures change the mutualistic relationship between coral and algae to one where corals don’t benefit.
• The corals expel the algae and become white.
• This has both community and ecosystem consequences.

• 50%
• About a quarter of this diffuses into the ocean (higher to lower concentration).
• This means that as the concentration of CO2 in the atmosphere increases, more of it diffuses into the ocean.
• The CO2 in the ocean turns into carbonic acid, leading to a pH drop.
• Lower ph makes it harder to form CaCO3 shells for mollusks and corals.

• Aspects of climate change can influence the rate of future climate change.
• Positive Feedback: Change in one factor drives change in the system that amplifies the initial change. (albedo)
• Negative Feedback: Change in one factor that drives changes in the system that diminishes the initial change.

• Temperature goes up
• Tundra warms up
• Organic matter is revealed from permafrost and is consumed by decomposers.
• More CO2 enters the atmosphere
• This is a short term change, in the long run, the growth of vegetation may propose a negative feedback cycle.
• As a result of this, global tundra has decreased significantly.

• The timing of seasonal activities such as;
• When snowshoe hares change their coat color.
• Flowering
• Emerging from pupa or other dormant stage
• Nesting or reproducing
• Organisms can use different cues to do these activities. Using photoperiod or temperature is common.
• Timing can be really important, especially in places that have distinct seasons.
• Phenological changes can change species interactions (such as pollinator x flower and parasite emergence x birds nesting). These types of mismatchings can lead to population crashes and community / ecosystem effects.

Different species have different displacement rates. Herbaceous plants and trees are slower at displacement, deeming them especially prone to risk.

• General health declines
• More physical hazards in the environment (head, floods, etc.)
• Increased occurrence of some diseases.
• Change in the distribution / abundance of some disease vectors. (zika virus, increased tick caused moose mortality)

• The beetle can occur at higher latitudes and elevations.
• Trees are often weakened by drought.
• The beetle also has two life cycles per year rather than one.
• Females bore holes in the pine bark, lay eggs and infect the tree with blue-stain fungus.
• Trees die due to phloem disruption and infection.

• Production will increase in some areas and decrease in others.
• On average, production will decrease.

• Since the 1990 Clean Air Act has been implemented, surface water sulfate concentrations have declined significantly in Europe and North America.
• 1987 Montreal Protocol to phase out CFC has lead to the recovery of the ozone layer (2065)
• Both of these events demonstrate the ability of nations and the world to overcome large scale environmental problems. This could also apply to climate change.

• Bradley et. al tracked these for 20 year periods:
• The arrival of migratory bird species
• The first song of non-migratory bird species
• The first bloom of flowering species
• 18 species changed somewhat, 17 species changed significantly.