Planetary boundaries

What are planetary boundaries, what are the consequences of crossing it and the study of this field

They are a limit/safe operating space of human activity on a global biological process. They have a tipping point that if crossed they will cause irreversible and huge damage to the environment.

The study of this is called inter-disciplinary

Give the first planetary boundary and explain if and why its been crossed, strategies to improve it and evaluation of these 

1. CLIMATE CHANGE BOUNDARY 

It is one of the core boundaries and has been crossed due to 

• green house gas emissions - so much that even stopping now would increase temp for decades

This is having an effect on extreme weather, weather patterns, agriculture and seas

Kyoto protocol in 1997 was created to lower emissions and to reduce pollution and burning of fossil fuels for gas these new biofuels where creates 

A biofuel = Fuel made from biological processes eg. anaerobic digestion of plant waste, industrial or houshold waster

+ less co2 is burned through fossil fuels

+ takes in the Co2 it releases

- Combustion of fossil fuels to start

- lots of space - food vs fuel

- deforesation

- requires lots of water

The types of biofuels

1. Bioethanol - digestion of starch in carbs and sugars to produce sucrose - fructose and glucose into ethanol and distilled using energy from fibrous waste combustion into bioethanol.

2. Biodiesel - vegetable oils are split into fatty acid chains and reacts with alcohols to produce it. produces 60% less co2 due to more hydrogen and water but more nitrous oxide

3. biogas - Its made from food digestion by enzymes amylase, lipase and protease into its products. Acetogenesis - fatty acid chains are shortened to produce CO2 water and energy. Methanogenesis - glucose is done the same. It occurs naturally at landfill but can be made into methane

What is the next boundary, has it been crossed and why and what are the effects?

Biosphere integrity boundary

This is the 2nd boundary to be crossed due to human activity changing the env. too quickly for natural selection, causing extinction and 'the ‘environmental services are no longer available

This is causing

• Mass extinction of marine species - ½ will be gone by 2100

• Coral reef destruction so loss of habitat and food - coral reefs are stressed so zooxanthine leave coral so it dies as no photosynthesis

• coastal communities like mangrove forests that absorb lots of CO2 destroyed due to salt sea level rise - too much osmosis

• Poles ice melting and sea level rise

What is the third boundary, has it been crossed and why has it been crossed 

Land system change 

Human activity has changed the env.  eg. deforestation

1. biofuels vs food

2. soya for cattle

3. cattle 

4. urban development

5. monoculture

It has be crossed 

We need to change diets and settle fuel vs food 

What is the fourth boundary, has it been crossed and why?

Biogeochemical flow `- the cycles on minerals through the nv which is vital for all organisms to build molecules

The problem

too much nitrogen means eutriphication and nitrous oxide which is a greenhouse gas

too much phosphate - eutriphication

What is the 5th boundary, has it been crossed and why?, what are the effects and what has been done to improve

Stratospheric ozone boundary

Ozone and oxygen are normally at equilibrium, however due to CFCs in packaging, spray cans etc. of halogenated hydrocarbons, it favors the breakdown of ozone. It also when exposed to UV it releases chlorine which breaks down so many ozone. This causes an increase in temp and poles melting

It was recovered due to banning CFCs

What is the 6th boundary, has it been crossed and why and the effects

The ocean Acidification boundary 

It has just been crossed due to a drop in pH drom 8.16 to 8.03. this is due to an increase in C02 which dissolves in water to form carbonic acid. This acid lowers pH and can damage and dissolve anthropod exoskeletons and mollsuc and coral bleeching. 

What is the 7th boundary and what are its problems

Atmospheric aerosol loading boundary

the limit of Particles in the atmosphere which is high due to burning of fossil fuels and dust from mines and quarries

Problems

• dust on leaves - no photosynthesis

• respiratory problems

• Reflects sunlight - greenhouse effect

What is the 8th boundary and what are the problems

Novel entities

Refers to the pollution of harmful waste eg. Nanoparticles, microplastic, pollutants and radioactive material

The final boundary, why is it crossed and what can we do?

Fresh water boundary

Fresh water in glaziers, lakes, ponds, underground are all depleting due to

• Agriculture - uses so much

• pollution of water

• use of water due to population increase

• climate change - less rainfall, more thermal expansion and sea level rise

Solutions 

1. Water efficiency 

2. water conservation

3. desalination - removing water from sea water 

• Reverse osmosis - forcing water against conc. gradient into fresh water - expensive and burns fossil fuels and produces brine (damage sea beds)

• Solar stills to heat it using solar panels - relies on weather

1. Drip irrigation - dripping onto plants

2. cleaning of rivers

What is the acronym to remember the boundaries

BOB IS CALF

Biosphere integrity

ocean acidification

biogeochemical flow

I- Novel entities

Stratospheric ozone

Climate change

Aerosol loading

Land system change

Fresh water