science final studying

what is life based on

carbon

how much carbon is in the atmosphere

little

albedo

reflectivity: color, absorption of energy

how does agri balance carbon

1. sends carbon to atmosphere

2. soil is central, can hold a little or a lot of carbon

what is foodprint analysis mostly made of

carbon footprint

yield loss

climate impacts conditions for agri, may be too hot/cold for best yield

which countries are most vulnerable to food insecurity bc of climate

africa and middle east

ten indicators of warming world

• Increased

  • Humidity

  • Air temp near surface

  • Temp over oceans

  • Sea level

  • Sea surface temp

  • Ocean heat content

  • Temp over land

• Decreased

  • Sea ice

  • Snow cover

    • Glaciers

industrial revolution impact

railroad, increased speed of travel

glacier cycle

In summer it melts a little, flowers bloom, pollen layers on glacier, snow covers and over time is compressed

why examine glacier cycle

Samples of what earth was like at the time: look at pollen content, amount, type

how to carbon date glaciers

• Bubbles of air are captured and entombed in ice

  • Can sample the bubble, figure out atmosphere at the time

  • Carbon dioxide and methane can be measured

  • At certain temp, cant predict amount of methane and carbon dioxide

    • Ex. in a cold enviro little is growing or decomposing, so levels will be low

are ambient cycles predictable

yes, up and down, can test concentrations

three milankovitch cycles

eccentricity, obliquity, precession

eccentricity

shape, changes every 100k years

obliquity

axial tilt, 40k years

precession

influence on orbit and rotation due to planetary gravitational effects, 20-25k years

what happens when milankovitch cycles are aligned

strong influence, explains pattern of ambient temp

More things grow, also decompose, biological activity

Half of carbon goes into atmosphere, half into soil

When cold more goes into the soil

When warm initially more goes down, but eventually it goes up

boreal forests

more carbon in soil

tropic forests

more carbon in atmosphere

how does ocean store a lot of carbon

Sucks up surplus carbon dioxide

When it hits water, it turns to carbonic acid and contributes to ocean acidification

In deep ocean, methane hydrates or balls of methane, looks like ice/snow

how is carbon stored in fossils

coal, natural gas, oila

are CO2 and methane levels high

yes

greenhouse gas meaning

bc greenhouses are built to bounce back heat and trap it like the gases do

thermals

as heat rises, air lifts and keeps it afloat

Light energy, plants/animals provide energy

how do greenhouse gases work

Certain amount of earth’s heat is sent out, Gases bounce this back, converts to heat

biggest GHG

CO2, doesn’t need a lot to make big impact

smaller GHG

methane (breaks down but more is added), nitrous oxide

montreal protocol substances

big molecules and have thousands of times greater warming potential

why are montreal protocol substances bad

Used for refrigeration

Controlled initially bc they attacked the ozone layer

Leaky refrigerators, circuit board cleaning substances, dry cleaners

Can sense from aerial surveillance, lots of pirate manufacturing

what agri influence on climate change is ignored

road transport: Fertilizer production, transport, etc.

15% to 50% of global emissions

food system impact

Animal manure releases a ton of methane

Fertilizer, etc,

meat production impacts

Preproduction, mechanical sources, non mechanical sources and sinks, postproduction, land use change

Most is during agri production, or mechanical and non sources and sinks

which is more efficient/saves carbon: eating local or ship across country

ship across country

what two elements are big gases based on

nitrogen and carbon

where do carbon and nitrogen gases come from

Most are either from the farm, soil management, land system change

why does irrigated rice make a lot of methane

standing water

enteric

cattle

soil mismanagement is

big contributor to CO2 emissions in US

what industry is nitrous oxide in

almost entirely agri bc mostly fertilizer

methane is from

food based, production, waste management, livestock

how to improve food system emissions

reducing red meat consumption, reducing fertilizer, better soil management

ACC

Anthropogenic climate change: human caused climate change

why is permafrost thawing bad

is very carbon rich, when it thaws it’s waterlogged, decomposes, releases lots of methane

where are peat lands and forests

Peat lands in the north, peat forests in the tropics

albedo

bouncing back of energy to atmosphere

big albedo bouncers

Asphalt and dark shingles are worst

Grass field bounces a lot back (Albedo wise, converting forest to grassland would increase climate change)

what land type is best to minimize albedo

forest, bc absorbs a lot of energy

how is ozone created

combustion, lighting, combustion engines, O3 instead of O2

what does ozone do

Filters UV radiation in stratosphere, but down here acts as air pollutant and GH gas

why is dust bad

Dust in air shields sun and reflects back to atmosphere

also Settled on glaciers absorbs more energy and accelerates melting

at what temp level do C3 plants grow better than C4

lower temps

what happens to plants as planet warms

microbial activity increases

Branches from plants are decomposed by microbes

Microbial activity tracks temperature

Returns carbon to the atmosphere, warms climate

terrestrial carbon sink

Ecosystem respiration increased when global photosynthesis drops

Need to be in safe climatic space

what happens with increasing global temp

space gets smaller and smaller

Less land suitable for agri

which countries benefit from increasing temps

canada and russia: can grow new crops

climate change impact on agri crops and animals

Warmer temperatures and hotter extremes reduce crop yields and increase animal loss from heat stress and disease.

climate change impact on agri livestock

Increased drought and precipitation deficits increases crop stress and reduces livestock yield.

climate change impact on agri rain

Increased frequency, intensity and/or amount of precipitation degrades and floods farms.

climate change impact on agri coastal

Salt water intrusion/rise in sea levels in coastal regions result in a reduction in usable cropland.

why does water level rise with climate change

Warmer water expands, can’t go down, goes up and down

Old Glaciers weight pushed land down

Where one level goes down, another rises, so Land was higher up 30k years ago

Draining water from aquifers that land settles down

climate change impact on agri atmosphere

Disruption of the movement of water in the atmosphere as a result of the dieback of tropical forests could cause major shifts in precipitation in key agricultural areas.

climate change impact on agri biodiversity

Climate change reduces biodiversity, such as by reducing the populations of pollinating insects, which can threaten agricultural resilience and crop productivity.

which major crops are most affected

corn and wheat, whereas tubers and rice benefit if theres water

evidence for current climate change

temperatures, sea level, weather patterns

historical patterns and causation of CC

Milankovich cycles, carbon cycle, greenhouse effect, albedo

Current change in climate caused by humans

role of agri in CC

Ag practices, soils, life cycle analysis, diets

All play a role but on-farm activities are the most important

Climate change and agricultural impact

Yield losses, changing crop and practice choices, security

We need to both mitigate and adapt

where will yield drop with CC

areas close to equator yield will drop

In contrast northern/colder areas yield will increase

is land distributed for food need

no, Land isn’t equally distributed for food need

mitigation

A human intervention to reduce the sources or enhance the sinks of greenhouse gases.

adaptation

The process of adjustment to actual or expected climate and its effects. In human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. In some natural systems, human intervention may facilitate adjustment to expected climate and its effects.

how will enhancing natural carbon sinks help CC

Cutting down tropic forests releases a lot of carbon

Need to adapt to realities

Growing things in different ways, different crop varieties

food crop CC change examples

Cacao is being lost bc of disease and CC, but political systems impact distribution of current surplus

Huge price change in rice, more important than specialty crops

1st scope of CC

what happens on your property/facility, what carbon you’re responsible for

examples of 1st scope CC

Natural gas for stoves, forklifts, cleansing agents that emit carbon

how much can you reduce 1st scope CC

reduce emissions directly

2nd scope of CC

energy is provided, but carbon costs are somewhere else

examples of 2nd scope of CC

Electricity, can buy solar power, accounting for it and responsible for emissions

3rd scope of CC

supply chain emissions, transport, fertilizer, etc.

examples of 3rd scope

Have some control over the supply chain

Don’t always know who should take responsibility for emissions, grey area

why are GHG higher on the farm than pre or post

Land involved

Fertilizer emissions get worse with increased temps

Emission trends differ on place greatly

Burning is big for pest control in some places

Peat soil continues to lose carbon as it decomposes

is harvesting wood carbon neutral s

no

why are forests big carbon sinks

Capturing carbon and releasing it into the soil

how to mitigate CC: general

reforest

big impact, low cost

avoid forest conversion

managing agri lands

cover cropping

how to mitigate CC: farm

adding trees

grazing

avoid grassland conversion

restore peatlands

Avoiding peat impacts

Coastal restoration

Avoiding coastal impacts

what does managing agri lands do

Biochar: collect leftover wood chips, scraps, burn it under tarp without oxygen and makes charcoal

Apply to fields, adds nonreactive carbon to soil

Won’t be broken down and returned to atmosphere

If material decomposes it adds GHG to atmosphere, as biochar it doesn't

what does cover cropping do

Grow a cover crop to prevent carbon loss to atmosphere from soil

Cornerstone of regenerative agri

Keep living roots in the soils

what does adding trees do

Act as windbreaks, control erosion, fruit crops

Keeping living roots in soil prevents carbon loss

what does restoring peatlands do

As soil dries up for agri it’s exposed to oxygen and loses carbon

Waterlogged nature keeps oxygen away from organic matter

where are there carbon stocks

peat forests, waterlogged areas

what does agri do to carbon stores

loses it

sustainable intensification

more stuff is on site

adapt technique

use nitrogen fixating bacteria and genetically engineer them to get nitrogen

calcium carbonate

lime

what is first thing removed in optimization

nitrogen fertilizer

BAU

business as usual

carbon market facts

Hard to determine value

Likely most viable approach

Many farmers are paid to sequester more carbon in the soil

Central to regenerative agri, makes it viable

soil and carbon stocks

key to balancing impact