apes global climate change

climate

long-term weather patterns

global climate change

changes in long-term patterns of atmospheric conditions involving ∆T, precipitation, and storm frequency + intensity

• caused by the Greenhouse Effect

important greenhouse gases

• CO2

• methane

• nitrous oxide

• chlorofluorocarbons (CFCs)

• tropospheric ozone

• CO

CO2

primary concern due to abundance

• current levels at their highest in 650,000-2,000,000 years

• major anthropogenic sources: fossil fuel burning + deforestation

• dissolves in the ocean and contributes to ocean acidification

methane sources

fossil fuel combustion, cattle, wastewater, rice agriculture

nitrous oxide sources

fossil fuels, agriculture, solid waste, wastewater

CFCs sources

refrigerants → not used anymore b/c of the Montreal Protocol

natural factors that can mitigate climate change

• ocean absorption of CO2

• more or less plant matter can affect CO2

indirectly indicators of global climate change

• preserved gas bubbles in ice

• sediment beds beneath bodies of water

• coral reefs

• tree rings

tree rings

• highly susceptible to growth changes due to heat and precipitation

• old growth forests = indicator of historical weather

direct atmospheric sampling

started 1958 by Charles Keeping → studied trends of CO2 concentration

• data showed an increase of CO2 concentrations from 315-383 ppm

• temperature measuring began 1820s

consequences of climate change

• less sea ice at North and South Poles

• melting of glaciers and land ice

• melting of permafrost

• more and more extreme heat waves

• changes in precipitation patterns

• increase in storm intensity and frequency

• shifts in ocean currents

hotter temperatures as a consequence of climate change

• 2024 was the hottest year on record for Earth

• top 10 warmest years all in the last decade

• heat is the leading cause of death from natural disasters

• leads to economic problems + stress on infrastructure → closure of schools and businesses

consequences:

• melting of permafrost → release of methane

• melting of land ice → rising sea levels

• ocean absorbs a lot of excess heat → too warm for sea life

• shifts in growing seasons and microclimates

more extreme weather events as a consequence of climate change

• more extreme heat waves

• more extreme cold

• more + stronger hurricanes, tornadoes, storms

• more forest fires

detriment to human health as a consequence of climate change

• more heat stroke

• more diseases → especially mosquito vector/waterborne

• increased respiratory damage due to pollution from forest fires

• less access to food and water

ecological concerns as a consequence of climate change

• habitat loss in sea level rise

• forest fires

• shifting climate conditions

• coral bleaching in warming oceans

• timing of seasonal events are creating complex effects in ecosystems

economic concerns as a consequence of climate change

• change in crops → climate changes

• damage to property and infrastructure → storms, sea level rise, forest fires

• less reliability of ecosystem services

mitigation

going after the root cause; actions that would reduce emissions of GHGs / absorb GHGs

strategies:

• prevent (stop emissions)

• undo (remove GHGs / block sunlight)

adaptation

search for ways to soften the blow of climate change and live in a warmer world

reduce emission options (mitigation)

• switch to natural gas

• switch to renewable energy

• alternative engines, driving less, public transportation

• consume less beef + meat

• purchase fewer items → manufacturing/shipping requires electricity and fossil fuels

• market mechanics → cap and trade

efficiency options (mitigation)

• more efficient electricity production (largest source of carbon emissions)

• more efficient cars (currently 15%)

• sustainable agriculture and land management

• recovering methane from landfills, treating wastewater, energy from solid waste

carbon sequestration options (mitigate)

• preserving forests and reforestation

• carbon offset → reduction in emissions somewhere else to balance out nonreductible emissions

• physical carbon sequestration projects → physically removing CO2 from atmosphere and depositing elsewhere

adaptation options

• sea walls → prevent flooding due to rising sea levels

• plant heat + drought resistant crops

• relocate cities

• expand wildlife reserves toward poles

• stockpile food + water

• conserve water

Kyoto Protocol

international treaty where major countries met to reduce GHG emissions (US didn’t sign)

• failed because no one really followed through and emissions went up

Paris Agreement

non-binding agreement between large countries to reduce emissions

• no one met goals

• US pulled out

• didn’t really “fail” because emissions still went down, but it wasn’t a success

ocean warming

ocean has absorbed over 90% of warming caused by GHG emissions → shows effects of global warming

• water has a high specific heat, so it can absorb a lot of heat before changing temperature

impacts:

• thermal expansion of the ocean → higher sea levels

• death of temperature-sensitive polyps on coral reefs → coral bleaching

• decrease in sea ice → loss of habitat (for polar bears mainly)

steps of ocean acidification

1. CO2 released

2. CO2 dissolves in ocean + makes carbonic acid

3. acid lowers pH + less carbonate available in oceans → problem for sea life w/ exoskeletons + coral reefs b/c of reaction with CaCO3 and less carbonate available to form CaCO3

impacts of ocean acidification

• less carbonate available for shelled organisms

• weakening of shells + coral structures due to reaction with acid

sea level rise

causes:

• thermal expansion of ocean

• melting land ice/glaciers

consequences:

• relocation of cities further inward

• habitat loss

decrease in livestock and crop diversity

• caused by Green Revolution → consolidation of mass-produced crop varieties; focused on higher yield strains

• few strains replaced native strains → became global due to irrigation, fertilizers, and pesticides

• greater chance of crop loss due to low genetic diversity → eg. corn fungus in the 1970s

HIPCO - H

habitat loss

• the greatest cause of decline and extinction

• most is due to human development

HIPCO - I

invasive species → outcompetes native species due to lack of natural predators

• eg. Kudzu Vine, Zebra Mussel, Silver Carp

alien/exotic species

species that live outside their historical range

invasive species

when alien species spread rapidly across large areas

HIPCO - P

pollution

• threats to biodiversity can come from toxic contaminants such as pesticides, heavy metals, acids, and oil spills

HIPCO - C

climate change

• concern: how climate change will affect temperature and precipitation

HIPCO - O

overharvesting

• when individuals of a species are removed at a rate faster than the population could replace them

• eg: dodo bird, American bison, passenger pigeon

single-species approach

help one species at a time → eg. legislation passing

ecosystem approach

create protected areas to conserve ecosystems

Lacey Act

prohibited transport of illegally harvested animals across state lines → primarily birds and mammals

• one of the earliest laws to protect species

Conservation on International Trade in Endangered Species (CITES)

prohibits international trade of threatened plants and animals

• international agreement b/w 175 countries

• red list → list of threatened species kept by the IUCN

Marine Mammal Protection Act

prohibits killing of marine mammals in the US and prohibits import/export of marine mammal body parts

• US Federal law

Endangered Species Act

authorizes FWS to determine which species can be listed as threatened/endangered and prohibits the harming of said species

• prohibits trade

• authorizes government to purchase habitats that are critical to the species

• restricts human activities → controversial