UNIT 9 APES

The Natural Greenhouse Effect

• Warms the earth’s lower troposphere and surface.

  • We wouldn’t be here without it!

• natural cooling process.

  • Large quantities of heat are absorbed by the evaporation of liquid surface water, and the water vapor molecules rise, condense to form droplets in clouds, and release their stored heat higher in the troposphere.

Greenhouse effect distribution picture

Major Greenhouse Gases

• 1.  H₂O 

• 2.  C0₂

• 3.  CH₄

• 4.  N₂0

• 5.  CFC’s

CFC’s are the only anthropogenic (meaning MAN MADE ONLY!) GH gas

carbon dioxide emmisions

• 33% transportation

• 31% electricity

• 16% industry

• 12% residential and commercial

• 8% other (non fossil fuel combustion)

methane emissions

• 32% natural gas and petroleum systems

• 27% enteric fermentation

• 17% landfills

• 9% manure management

• 6% coal mining

• 9% other

nitrous oxide emissions

• 74% agricultural soil management

• 6% wastewater treatment

• 5% stationary combustion

• 5% chemical production

• 5% manure management

• 4% transportation

• 1% other

good vs bad ozone picture

overview of US greenhouse gas emissions in 2020

• 79% carbon dioxide

• 11% methane

• 7% nitrous oxide

• 3% fluorinated gases

sources of US greenhouse gas emissions in 2020

• 27% transportation

• 25% electricity

• 24% industry

• 13% commercial and residential

• 11% agriculture

Carbon dioxide (CO₂)

human sources:

Fossil fuel burning, especially coal (70–75%), deforestation, and plant burning

Methane (CH₄)

human sources:

Rice paddies, guts of cattle and termites, landfills, coal production, coal seams, and natural gas leaks from oil and gas production and pipelines

Nitrous oxide (N₂O)

human sources:

Fossil fuel burning, fertilizers, livestock wastes, and nylon production

Chlorofluorocarbons (CFCs)*

human sources:

Air conditioners, refrigerators, plastic foams

• ONLY one that gets to the stratosphere

Hydrochloro-fluorocarbons (HCFCs)

human sources:

Air conditioners, refrigerators, plastic foams

Hydrofluorocarbons (HFCs)

human sources:

Air conditioners, refrigerators, plastic foams

Halons

human sources:

Fire extinguishers

Carbon tetrachloride

human sources:

Cleaning solvent

water vapor

• most abundant GHG

• spends a short amount of time in the atmosphere

• isn’t a major contributor to climate change

Prehistoric Climate Change

• The ONLY trend is that our climate is not fixed…that means that changes in our climate are normal.

• Over the past 900,000 years the troposphere has undergone global cooling and global warming.

• These alternating cycles are called glacial and interglacial periods (Milankovitch Cycles).

• Severity of glacial and interglacial periods depends on the tilt of the earth and the Earth’s distance from the Sun

climatic temperature trends on Earth

• CO₂  levels rise, so do temperature and sea levels

•  CO₂  levels have risen far faster in the last 200+ years that at any other point in Earth’s geological history

• At the time of the industrial revolution,CO2 concentration was ~288 ppm. This means that since the Industrial Revolution, CO 2 levels have risen by ~48%.

Prehistoric Climate Forensics

analyze air bubbles trapped in ice cores, and ocean/lake sediment cores to uncover information about past:

• temperature trends

• greenhouse gas concentrations

• snowfall 

• forest fire frequency

  Analyze calcium carbonate foraminifera exoskeletons

  • Carbon used for determine age

  • Oxygen used to determine temperature

Other tropospheric temperature mediators

• Clouds can have a warming effect and a cooling effect.

  • Warming:  clouds absorb and release heat into the troposphere

  • Cooling:  by reflecting more sunlight back into space

  Particulates (ash, sand, dust)

  Can increase cloud cover (can be natural or man made).

• Some have a high albedo and reflect more incoming sunlight back into space during the day.  

  • Will keep day time temps COOLER as sunlight reflected out

  • BUT nights become warmer because heat cannot be radiated back into space.

albedo

how much sun something reflects

-white has a higher albedo than black surfaces 

positive feedback loops

• As temperatures increase, sea ice continues to melt, causing a decrease in albedo

• As albedo decreases, temperatures rise even more, causing more sea ice to melt, and so on

Sea Level Increase

Can be positive- newly created habitats on flooded continental shelves

Can be negative- deeper communities may no longer have adequate access to sunlight for photosynthesis

• Greatest amount, however, will come from thermal expansion (water increases in volume at higher temperatures)

More air pollution-related deaths

With warmer temps, we can expect to see a rising level of photochemical smog formation and more poor air quality days

• lead to a further increase in the number of respiratory condition cases and premature deaths

• by 2100, we could see an extra 200,000 deaths globally due to worsening air pollution.

Melting Permafrost

The permafrost is a major reservoir of methane (remember the methane hydrates we discussed in Unit 6?)

• As the permafrost thaws, methane is released into the atmosphere

• The methane absorbs heat, which in turns warms the tundra more, leading to more permafrost thawing.

ocean acidification

The decline in ocean pH due to an increase in CO₂ diffusion into the oceans

This increased diffusion is due to increasing CO₂ levels in the atmosphere and is happening DESPITE ocean temperatures increasing

if TOO much CO₂ is absorbed…

• Than the ocean will experience a decrease in pH as more carbonic acid is made.

  • H₂O + CO₂ —> H₂CO₃ (carbonic acid formation)

  • Carbonic acid easily dissociates into ions (weak acid)

    • H₂CO₃ —> H⁺ + HCO₃^-  (most common)

• Acidic water can eat away at the calcium carbonate shells of organisms and coral reefs…

  • CaCO₃ + 2H⁺ —> Ca²⁺ + H₂CO₃

coral bleeching

Corals have a mutualistic relationship with zooxanthellae, a type of algae

The zooxanthellae provide nutrients to the coral, and the coral provide a habitat for the zooxanthellae

When the coral get stressed, they eject the zooxanthellae. While some corals are able to recover, many do not.

Stresses linked to bleaching events

• Warmer/colder than normal water temps

• Nutrient pollution from runoff

• Overfishing

• Tourism industry

• Changes in salinity

• Dredging turbidity

  ocean acidification has ZERO to do with coral bleaching

why we need coral reefs

Corals are home to more than 25% of all marine life, provide protection of the shoreline from storm surges and from excessive erosion, are habitat for fish that humans consume, provide a source for ecotourism money, and are potential sources of medicine for various ailments

Ocean and Wind Currents

• Gulf stream currents play a large part in helping to moderate surface temps.

  • No gulf stream= Europe and NE US covered with glaciers.
    Wind current help transport heat throughout the Earth. 

• Climate change could potentially disrupt these convection currents as well as the jet stream.

How Can We Reduce the Threat of Global Warming

• Improve energy efficiency to reduce FF use

• Shift from carbon based fuel to a mix of carbon free

• Store as much C0₂ as possible

  • Plant more trees

  • Soil sequestration

  • Inject into deep ocean

  • Pump it deep into ground into unmineable coal seams

Kyoto protocol

• Require 39 developed countries to cut emissions of C02, CH4 and N20 

  • Does not require poorer developing countries to make any cuts

  • The US withdrew its participation in 2001

2015 Paris Climate Change Treaty

• Kyoto Protocol, take 2

• Will be a legally binding document to limit greenhouse gas emission… or not

Pledge may be better term

• The rapid growth of China = more carbon emissions. 

• But these emissions caused by Western countries outsourcing their operations to China

• should the country of the producer or the consumer be penalized? 

future of global warming

• CO₂ regulation in US…it’s coming

• New power plants will be given a strict limit of CO₂ emissions

• Will have to invest in cleaner burning fuels or carbon capture & storage

Using the Marketplace to Reduce/Prevent GH Emissions

• GH gas emissions trading program

• Industries & companies earn GH gas emission credits by improving energy efficiency, switching from coal to natural gas and adopting certain farming ranching and soil building and conservation practices.

Sequestering Carbon—3 steps

• Capture CO₂ from power plants or industrial processes

• Compress & transport CO₂ (usually in pipelines).

• Underground injection and geologic sequestration of the CO₂ into deep underground rock formations. 

  • Mile below

  • In porous rock with impermeable, non porous cap

Potential Sequestration Sites

• Potential sites can include depleted oil/gas reserves, saline formations, and unmineable coal seams

• We do not have a lack or storage sites. The problem, however, is that retrofitting coal-burning power plants with carbon sequestions technology is currently cost-prohibitive in many areas

• carbon capture and storage on only seen in the small-scale for now.

 Trends of Ozone Due to Human Activities

• Ozone is the Earth’s sunscreen.  It filters out UV which allows life to exist and protects us from sunburn, skin & eye cancer.

• If there is a decrease the beneficial ozone in the stratosphere then there is an increase the harmful ozone in the troposphere

  • called photochemical smog

Ozone Depletion in the Stratosphere

• Ozone layer in the stratosphere keeps about 95% of  UV radiation from reaching the surface of the Earth.

• A hole (ok, really THINNING) has developed in the ozone layer as a result of CFC use.

• CFC’s 

  • thought to be “dream” chemical 

  • inexpensive to produce

  • used as coolants, propellants, cleaners, fumigants and bubbles in plastic foam.

problem with CFC’s

• CFC’s remain in the troposphere because they are insoluble in water and chemically unreactive.

• These chemicals are lifted into the stratosphere by drift convection and mixing of air.

• Once CFC’s reach the stratosphere they break down into highly reactive Cl, Br and I atoms which accelerate the breakdown of ozone.

• Each CFC molecule can last for 65-385 years in the stratosphere.

chlorine atom

 A single chlorine atom removes about 100,000 ozone molecules

Montreal Protocol

phase out of substances responsible for ozone depletion, starting in 1989

Harmful effects of UV radiation

• Skin cancer (ultraviolet radiation can destroy acids in DNA)

• Cataracts and sun burning

• Suppression of immune systems

• Adverse impact on crops and animals

• Reduction in the growth of ocean phytoplankton 

• Degradation of paints and plastic material

Cancer are You Most Likely to Get from UV

• Even one severe sunburn doubles you chance of getting squamous or basal cell skin cancers.

• Malignant melanoma-spreads to other organs

• 3 or more blistering sunburns …

        before age 20 ….

              5 times more likely to develop 

              malignant melanoma

Extinction

• The ultimate fate of all species just as death is for all individual organisms

• Species tend to exist for 1-10 million years

• 99.9% of all the species that have ever existed are now extinct

Local extinction

when a species is no longer found in an area it once inhabited, but is still found elsewhere in the world.

• Many crocodilian species have experienced localized extinction, particularly the saltwater crocodile (Crocodylus porosus) which has been extirpated from Vietnam, Thailand, Java, and many other areas.

Ecological extinction

occurs when so few members of a species are left that it can no longer play its ecological roles in the biological community.

• Size structures and densities of sea urchins are correlated with the presence of sea otter populations, and because they are the principal prey of this keystone predator, the sea otters were most likely the main determinants of the differences in sea urchin populations. With high sea otter densities the kelp consumption by sea urchins in these kelp forest was severely limited, and this made competition between algal species the main determinant in survival. However, when sea otters were absent, kelp consumption by the sea urchins was greatly intensified to the point of decimation of the kelp forest community.

Biological extinction

when a species is no longer found anywhere on earth…this is FOREVER!

• Père David's Deer, Elaphurus davidianus extinct in wild since at least 1865

• Scimitar Oryx  Oryx dammah extinct in wild since at least 1865

• Caribbean Monk Seal Monachus Tropicalis

  Extinct since 2008 (officially)

Endangered species

has so few individual survivors that the species could soon become extinct across all or most of its natural range.

Threatened species

still abundant in its natural range but because of declining numbers is likely to become endangered in the near future.

Characteristics of Species Prone to Ecological and Biological Extinction

• Low reproductive rate

  • Blue Whale, Panda

• Specialized niche

  • Panda, Birds of Paradise 

• Narrow distribution

  • Island Spp., Elephant seal

• Feeds at high trophic level

  • Asian Lion, Polar bear

Anthropogenic Causes for Extinction: HIPPCO

• Habitat Fragmentation

• Invasive Species

• Population growth

• Pollution

• Climate Change

• Overexploitation

  • Poaching

  • Overhunting/overharvesting

Anthropogenic Causes for Extinction:Habitat Fragmentation

Loss of habitat leads to a loss of specialists, which, in turn, leads to a loss of generalists. Loss of habitats also leads to decreases in species that have large territorial requirements.

• The effect of habitat fragmentation has varies from species to species in an environment

Anthropogenic Causes for Extinction:Invasive Species

Tend to be r-selected species. Can outcompete native species, driving down their populations.

• Also known as aliens, invasive, exotic, transplant, introduced and non-indigenous

• evolve somewhere are deliberately or accidentally introduced into a community.

• Can threaten the long-term survival of specialists

Zebra Mussel

• Arrived from Europe, introduced into Great Lakes by BALLAST WATER

• Reproduces rapidly 

• Has no natural enemies

• Displaced natural mussel species

• Rapidly taking over waterways in US

• Clogs pipes

• NOW IN TEXAS

How are alien species able to take over an ecosystem?

as in r selected species. Most successful alien species are r selected

• One way to control an alien/invasive species is to introduce another non native species to control it (bring in it’s predator maybe)… Good/Bad?

example of controling an alien/invasive species

• To control purple loosestrife, introduced insects that ate its leaves

• Introduced ladybugs to control populations of invasive insects.

• Parasitic wasps or fungus to control fire ant populations

• Bacteria to control animal or insect pests---like Bt.

Reducing Threats from Invasive Species

• inspect imported goods that are likely to contain invader species

• identify major harmful invader species and pass international laws banning their transfer from one country to another.

Population Growth

Increased urbanization puts humans in direct competition with animal species.

Pollution

Pollution decreases the quality of the air, soil, and water.

Climate Change

Causes habitat loss via changes in temperature, precipitation, and sea level rise

Extinction Threats from Poaching and Hunting

• Smuggling wildlife is the third largest and most lucrative illegal cross border smuggling activity after weapons and drugs

• Poverty

  • Poor people struggling to survive in areas with rich wildlife kill or trap species to make enough money to survive and fee their families.

• Poaching

  • Live mountain gorillas- $150,000

  • Rhinoceros horn- $28,600/kg

  • Bengal tiger fur -$100,000

• Poaching has led to the extinction of several subspecies of rhino. The rhino are killed solely for the ivory in their horns.

International treaties

• reduced the international trade of endangered and threatened species, but enforcement is difficult.

• 1975 Convention on International Trade in Endangered Species (CITES)

  • Lists 900 species near extinction that cannot be commercially traded as live specimens & 29,000 other threatened species that are restricted.

• Convention on Biological Diversity (CBD)

  • three main goals: the conservation of biological diversity, the sustainable use of its components, and the fair and equitable sharing of benefits arising from genetic resources

National laws

• Lacey Act of 1900 prohibits transporting live or dead wild animals across state borders without a federal permit.

• Endangered Species Act of 1973 (ESA) identified and legally protected endangered species in the US and abroad.

  • Most far reaching and controversial environmental laws passed

Protecting Wild Species

Habitat Corridors

• Habitat corridors allow for populations of animals to be able to access areas of habitat which they  would otherwise be cut off from due to habitat fragmentation.

Sustainable Resource Use

• Ex- sustainable forestry: replanting cut down trees, reusing wood, IPM to prevent spread of disease, removal of diseased trees, prescribed burns to reduce natural forest fires