Week 6 - Air Pollution

Question 1

Indirect methods of monitoring air pollution

Answer 1

• Remote sensing
• Indirect sampling

Question 2

Air mass factor caclulation

Satellite measurement viewing geometry and methane retrieval

Answer 2

Solar zenith angle + satellite viewing angle

Question 3

Limitations to methane monitoring?

Answer 3

• Clouds,aerosols, surface- reflectivity issues
• Large pixel sizes introduce uncertainty

Question 4

Indirect sampling method?

For Methane etc.

Answer 4

Use of diffusion tubes, lichens/other surfaces that absorb/ reflect pollutants over time

Question 5

How does remote sensing work?

Answer 5

Molecules absorb sunlight/terrestrial radiation at specific wavelengths

Question 6

Why is methane monitoring easy using targeted measurements?

Answer 6

Methane has fine line absorption

Question 7

Surface temp of earth due to greeenhouse effect?

Answer 7

288K

Question 8

Global warming potential (GWP)

Answer 8

Measure of relative importance for climate of emissions of a gas emitted now, compared to the same mass of CO2 at a specific time

Question 9

Radiative forcing (RF)

Answer 9

Measures how the global change in atmospheric concentrations since the 1750s has perturbed Earths radiation budget

Question 10

GWP of CH4 compared to CO2

Answer 10

CH4 has higher GWP than CO2

Question 11

RF of CH4 compared to CO2

Answer 11

CH4 has a lower RF than CO2

Question 12

Lifetime of N2O vs NOx

Answer 12

N2O has a long lifetime- global mixing
NOx is short lived- local/regional

Question 13

Climate impact of N2O vs NOX

Answer 13

N2O- Strong GHG- ozone depletion
NOx- indirect- CH4 reduced= cooling but O3 increases= warming

Question 14

Ecosystem impacts of N2O vs NOx

Answer 14

N2O- global warming, UV via ozone depletion
NOx- acid rain,eutrophication, plant damag

Question 15

Chemical role N2O vs NOx

Answer 15

N2O- stable in troposphere but breaks down in stratosphere
NOx- reactive, forms ozone and nitrates

Question 16

Role of N2O vs NOx- ozone

Answer 16

N2O- destroys stratospheric ozone
NOx- created ground level ozone

Question 17

Mitigation of N2O vs NOx emissions

Answer 17

N2O- difficult- diffuse sources (fertilisers)
NOx- easier e.g. emissions control/tech upgrades

Question 18

Climatic impact of NOx

Answer 18

• Reduces CH4 via OH radicals = cooling effect
• Forms tropospheric ozone= warming effect
• Contributes to nitrate aerosols= slight cooling effect

Question 19

What chemicals form acid deposition by dissolving in water droplets and dissociating?

Answer 19

SO2 and NO2

Question 20

Effects on the ecosystem of acid deposition?

Answer 20

• Soil acidification
  ->Base cations leached (Ca2+,Mg2+)
  ->Stunted growth in plants
• Reduced pH in water <5
  -> Fish die

Question 21

Sources of eutrophication

Answer 21

Excess N and P from fertilisers, livestock, sewage etc.

Question 22

Atmospheric soil processes- eutrophication

Answer 22

• Soil nitrification- NO3 leaching- aquatic N loading
• Aerosol deposition of N - NH3-> NH4+ aerosols

Question 23

Ecosystem effects of eutophication

Answer 23

• Algal blooms/hypoxia
• Reduces biodiversity- favours nitrophilous species

Question 24

N deposition critical load?

Answer 24

10-15kg

Question 25

Formation of tropospheric ozone

Answer 25

Secondary pollutant: NOx+VOCs+sun= O3

Question 26

Atmospheric behaviour of O3 (ozone)

Answer 26

Lifespan= days to weeks --> regional transport Influenced by aerosols, temperature, meteorology

Question 27

Ecosystem effects of ozone

Answer 27

O3 enters stomates --> produces reactive oxygen species (ROS) --> photosynthesis reduced

Question 28

Evidence for impacts of air pollution on human health

Answer 28

- Epidemiology - Lab experiments - Biology/genetics

Question 29

Models of exposure- air pollution

Answer 29

WHO estimates 7 million people die from air pollution/ year globally

Question 30

Key health concerns of air pollution on human health

Answer 30

- PM 2.5 - NO2 -O3

Question 31

Health concerns of PM 2.5

Answer 31

Can penetrate alveoli and bloodstream

Question 32

Health concerns of NO2

Answer 32

Can lead to respiratory inflation/lung function decline

Question 33

Health concerns of O3

Answer 33

Exacerbates asthma, reduces lung function and increases cardiovascular risk

Question 34

What is Ozone Depletion Potential (ODP)

Answer 34

Measures the relative ability of a substance to damage the ozone layer compared to trichloromethane (CFC-11) which has an assigned ODP on 1.0

Question 35

What is the role of the UK Centre for Ecology & Hydrology (UKCEH)?

Answer 35

UK’s leading centre for environmental science across water, land, and air, promoting sustainable coexistence of people and nature.

Question 36

How many scientists and sites does UKCEH manage?

Answer 36

500 scientists across four UK sites, Ghana, and 10 overseas sites, managing 130 terrestrial, 33 freshwater, 88 lowland, and 44 upland habitat sites.

Question 37

What are the six science areas of UKCEH (under restructuring)?

Answer 37

1. Atmospheric Chemistry and Effects, 2. Biodiversity, 3. Hydro-climate, 4. Pollution, 5. Soils and Land Use, 6. Water Resources.

Question 38

What is nutrient pollution and its impacts?

Answer 38

Excess nitrogen/phosphorus from farming, sewage, and animals causes eutrophication, algal blooms, and "dead zones."

Question 39

What does the Auchencorth Moss site study, and what event did it track?

Answer 39

Monitors atmospheric pollutants (NO₂, PM₁₀, PM₂.5, NH₄⁺, SO₄²⁻, Hg in rain); tracked the 2014 Icelandic volcanic eruption.

Question 40

What are the key findings from the Whim Bog experiment?

Answer 40

Studied NH₃ and N deposition (8-56 kg N ha⁻¹ y⁻¹); found 85% species loss over 10 years due to NH₃, showing biodiversity impacts.

Question 41

What does the SAFE Project in Borneo investigate?

Answer 41

Examines rainforest-to-oil palm transitions, focusing on biodiversity loss, carbon/nitrogen cycling, and GHG emissions (CO₂, CH₄, N₂O).

Question 42

What is the RERTA Project, and what does it test?

Answer 42

Tests riparian buffer restoration in Indonesian oil palm plantations to reduce GHG emissions and improve biodiversity/yield using BACI design.

Question 43

What does the Bird Island (Sub-Antarctica) study focus on?

Answer 43

Measures N₂O and CH₄ emissions downwind from penguin colonies, finding high spatial variability in developed soils.

Question 44

How does the Arctic GHG Fluxes project in Finland and Sweden contribute to methane research?

Answer 44

Compares aircraft, eddy covariance, and chamber measurements of CH₄ fluxes in wetlands, showing variations by vegetation class.

Question 45

Compare N₂O and CH₄ emissions between arable and bioenergy crops in UK/Europe trials.

Answer 45

Arable crops emit more N₂O due to fertilizers; bioenergy crops (e.g., Miscanthus, Willow) show CH₄ uptake; Sitka spruce contributes 40% of UK isoprene/monoterpene fluxes.

Question 46

What are the main sources of PM₁ emissions in urban air quality studies (Nairobi, London, Beijing, New Delhi)?

Answer 46

Cooking aerosols dominate PM₁ emissions (~90%), with traffic contributing a minor ~10%.

Question 47

Evaluate the environmental impact of nutrient pollution from pet waste.

Answer 47

Cat and dog waste contributes nitrogen/phosphorus equivalent to 3% of global livestock, impacting sensitive ecosystems.

Question 48

Assess the benefits and environmental challenges of oil palm expansion.

Answer 48

High yield (7x soya), wealth, bioenergy. Challenges: Biodiversity loss, altered microclimate, GHG emissions (CO₂, CH₄, N₂O), nitrate pollution.

Question 49

Discuss the advantages of Controlled Environment Agriculture (CEA) and areas needing further research.

Answer 49

CEA uses 1% water of conventional crops, reduces GHGs/pesticides, and is weather-proof, but its environmental impacts require further study.