L7 Flashcards
How much of the habital land surface is for agriculture and how much for forests?
50% agriculture
37% forests
Of the agricultural land how much is for crops and how many calories globally are derived from plants?
23% of ag land
82% of calories globally
How much of agricultural land is for livestock and how much does this make up of the global calorie supply?
77% land
18% calories
What is the global living planet index and how has it changed from 1970 to 2014?
Average abundance of 16,704 populations representing +4,000 species monitored across the globe
decline 60%
decline in the abundance of most wild animals due to the rapid acceleration in global land use
diversity and abundance have reduced
what does AFOLU stand for?
Agriculture, forestry and other land use
How much of anthropogenic emissions is AFOLU responsible for?
~1/4
50% of this is attributable to land use change from forest to crop land for instance
50% Ch4 and N2O from agricultural management
What is the relationship betwen global Co2 emissions, CH4 and N2O emissions with AFOLOU?
AFOLU is responsible for a minority of Co2 emissions ~15% of Co2 emissions and ~12% of all emissions
but
a majority of CH4 and N2O emissions
>50% of total Non-CO2 emissions
~12% of all emissions
What processes generate AFOLU emissions?
- Land use change and forestry is a big contributor
- Entric fermintation - methane produced in the body of a cow
- Rice cultivation - water demanding plants that also require methane
application of manure - fertiliser - or synthetic and the production of ammonium nitrate in factories
How are agricultural emissions distributed globally?
Heterogenous distribution with hot spots in western Europe and south east asai
- function of latitude
peat burning a big emitter
mid latitude use of synthetic nitrogen fertilizers
How much carbon are forests sequestering a year?
arond 4 gigatonnes a year
How much do agirculture emisisnos are from synthetic fertilisers?
12% of total Non-co2 ag emissions
What is the pattern of fertiliser use over the last 60 years?
Growoth
one of the most important industrial processes - haber bosch process that creates fertilisers was created in WW2
Where does No2 come from?
-74% from agricultural soil management
8% stationary combustion, primary power plants
6% industry or chemical production
How does the nitorgen cycle work?
Organic matter and N2 in the air –> NH4 –> No3 –> No2 (nitrogen dioxide which causes smog) –> No (nitric oxide) –> N2O (nitrous oxide a strong ghg)
this last reaction that produces a GHG can only occur if there is nitrate handing around in the soil
by adding fertiliser and increasing nitrate in the soil we accelerate the process that produces a ghg
How much of ag emissions are from manure?
15% of total non-co2 emissions
How is methane produced in manure breakdwon?
No oxygen in stored manure –> anaerobic biological activity –> methane production
HOw is carbon dioxide prouced in manure breakdown?
Oxygen present in stored manure –> aerobis biological acivitiy –> carbon dioxide produced
usually more desirable than the Ch4 producing due to the more potent ghg effect of Ch4 compared to Co2 ==> about 25x
How much of the non-co2 emissions in ag are from entric fermentation?
32-40%
What is entric fermentation?
Microbs in the cos stomache break down cattle feed into useable sources and protein that produce methane - which is burped or faster out
95% through burping
What contribution does global livestock contributes to total emissions? - and what is the break down of this
14.5% of total emissions
45% feed production and processing
39% entric fermentation
10% manure management
emissions from AFOLU are mainly meat -driven
How does agriculture and land use change impact emissions?
land use change is necessary to develope cropland and pasture – drives Co2 emissions
What are some supply-side measures to reduce supply-side measures?
-Reducing deforestation
- improved management of crop plants and livestock
- improved nutrient management
-mixed production systems
What demand-side measures can be used to mitigate agricultural emissions?
- Changing diets
- reduced food loss and waste
How has cropping intensity helped?
We have been able to grow a population and feed them without a growth in crop land - increase crops produced per unit land area
but
deforestation is projected to continue without a major change in agricultural innovation
How much has higher crop yeilds reduced emissions since 1961?
161 gtc emissions avoided
due to intensive management of land and the production
in organic farming the yeilds are considerably smaller
however
yeilds are predicted to be lost due to drought and heat stress - current practices and formulas might not work in different climate futures
How does genetic modification help agriculture?
modify to tolerate warmer or drier conditions in order to have the same crop to land management that we had in the past
Why does increase crop intensity and yeilds not always lead to land sparing?
agricultural impacts and footprint are the result of economic and personal decisions made by famres
farmers are profit driven - buy more land and produce the same amount - motivated to support their families and max profit not reduce land use
What is the concept of a clean cow?
Give a cow an enzyme inhibitor added to feed to reduce the amount of methane that it produces
allows the cow to extract the nutrients from what they are eating
but aimed to reduce emthane emissions by 25%
Why is the timing of fertiliser improtant?
Has an impact on N2O emissions - apply the fertiliser when the plant is growing so it doesn’t participate in the negative reaction
if plants are too big then the fertiliser in utilised effectively
innovation in drone fertilisation to apply to plants without tractors
What is a mixed production system
Idea of regenerative farming - no specific meaning but idea that there is a closed loop - livestock produces manure that you can then apply to crops and decrease the intensityof your good
but each farm ecosystem behaves differently - insufficient evidence that an integrated farm system has a consistent impact
What is organic farming?
organic production is an overall system of farm management and food production that combines best environmental practices, a high level of biodiversity, the preservation of natural resources and the application of high animal welfare standards
What are the key principles behind organic farming?
- no use of chemical pesticides and synthetic fertilisers
-antibiotics are severely restricted - GMOS not allowed
- crops are rotated
What is the issue with less intensive agricultural production?
It requires more land to produce the same amount of food
not impossible to have the same yield but only on a number of plant species like fruit grown orchards
What are some issues with organic systems?
Yields are not sufficiently high- have to import food from Europe or outside Europe –> potentially land use changes associated or other emissions
differing amounts of deforestation
What amount of agricultural emissions is from transporting food?
~4%
but this is not a huge impact as say eating less meat
How much of global ghg emissions come from food loss and waste?
6%
1/4 of food we produce is never eaten
What are the pros and cons of eating a lower-meat diet?
strongly reduce agircultural emissions but it can be hard to motivate behavioural change
other organic or local food preferences don’t necessarily reduce the climate impact of agriculture
