Sustainability and Climate Change - Lesson 5: Carbon Economy

Learning Outcomes

Explain how carbon footprint is measured.
Discuss the types of carbon market.
Describe the difference between Carbon Neutral and Net-Zero Carbon.

Greenhouse Effect (Recap from Lesson 1)

Definition: The greenhouse effect is a natural process where greenhouse gases absorb infrared radiation, warming the Earth.
Greenhouse Gases: Gases in the atmosphere that absorb infrared radiation (heat). Examples include:
- Carbon dioxide
- Methane
- Nitrous oxide
- Ozone
- Water vapor
Importance: The greenhouse effect keeps the planet at a habitable temperature of $15^\circ C$ . Without it, the Earth's surface temperature would be around $-18^\circ C$ , making it impossible for organisms to survive.

Carbon Cycle

Carbon is a chemical element essential to all living and non-living things.
The carbon cycle describes how carbon circulates around the planet.
Different parts of the cycle store carbon for varying lengths of time.

Blue Carbon

Definition: Carbon captured and stored by coastal and marine ecosystems like mangrove forests, seagrass beds, and tidal marshes.
Coastal ecosystems store approximately 70% of total carbon sequestered by the world's oceans, despite occupying less than 0.5% of the ocean surface area.
Mangroves, seagrass, and tidal marshes store more carbon per unit area than terrestrial forests.
Seagrasses: Absorb carbon from seawater to build their leaves and roots, securing sediment and dead organic matter.
Mangroves: Absorb carbon dioxide from the atmosphere through photosynthesis, storing carbon in their leaves, wood, roots, and sediments.
Tidal Marshes: Store carbon in vegetation and carbon-rich soil.
Threats: Blue carbon ecosystems are being degraded at an alarming rate (1-7% per year).
- Causes: coastal development, unsustainable harvesting, destructive fishing, and pollution.
- Impact: Reduces their capacity to store carbon and support fisheries, turning them from carbon sinks into carbon sources.
Protection & Restoration: Crucial for humanity.
- Includes Marine Protected Areas and blue carbon credit systems.

Urgency of Carbon Management

Carbon dioxide (CO2) accounts for about 75% of global greenhouse gas (GHG) emissions, leading to global warming.
To limit global warming to $1.5^\circ C$ above pre-industrial levels, GHG emissions need to peak before 2025 and be reduced by 43% by 2030 (IPCC AR6).
Without change, climate impacts such as heat waves, drought, forest fires, and sea level rise will intensify.
We need to track GHGs released due to human activities, known as carbon footprints.

Global Warming Potential (GWP)

Not all greenhouse gases have the same impact on global warming.
GWP allows comparisons of the global warming impacts of different gases by converting all emissions into a common unit: $kgCO2e$ or $tonnes CO2e$ .
Definition: A measure of how much energy the emissions of 1 tonne of a gas will absorb over a given period of time, relative to the emissions of 1 tonne of carbon dioxide ( $CO_2$ ).
The larger the GWP, the more a given gas warms the Earth compared to $CO_2$ over that time period (usually 100 years).

Global Warming Potential Examples

Carbon Dioxide ( $CO_2$ ): GWP = 1 (from fossil fuel combustion and cement production).
Methane ( $CH_4$ ): GWP = 27.9 (from fossil fuel, rice paddies, landfill waste, and livestock).
Nitrous Oxide ( $N_2O$ ): GWP = 273 (from fertilizer, fossil fuel combustion, and industrial processes).
Hydrofluorocarbons (HFCs): GWP = 140 - 11,700 (substitutes for ozone-depleting substances, used in semiconductor manufacturing, insulation, refrigeration, air conditioning, and heat pumps).
Perfluorocarbons (PFCs): GWP = 6,500 – 9,200 (from aluminum production and semiconductor manufacturing).
Sulphur Hexafluoride ( $SF_6$ ): GWP = 24,300 (from electrical transmission and distribution, and magnesium production).
Nitrogen Trifluoride ( $NF_3$ ): GWP = 17,400 (from semiconductor manufacturing).

Formula for GHG Conversion

$Emissions (tCO_2e) = Emissions (tonnes) \times GWP values$
Example:
- 1 ton of $CH4 \equiv 27.9$ tons of $CO2$ equivalent ( $tCO_2e$ )
- 2 tons of $N2O \equiv 2 \times 273$ tons of $CO2$ equivalent ( $tCO2e$ ) = 546 $tCO2e$
- Total $CO2e = 27.9 + 546 = 573.9 tCO2e$

Emission Estimates Using GWP

GWP allows greenhouse gas (GHG) emissions to be added up and expressed as $tCO_2e$
Some emission factor databases (e.g., DEFRA) already include $kgCO_2e$ , so no manual GWP conversion is needed.
However, if datasets provide the greenhouse gas emissions separately, a GWP value needs to be applied.

Carbon Neutral vs. Net-Zero Carbon vs. Climate Neutral

Carbon Neutral:
- Means that any $CO_2$ released into the atmosphere from a company’s activities is balanced by an equivalent amount being removed.
Climate Neutral:
- Refers to reducing all GHGs to the point of zero, while eliminating all other negative environmental impacts that an organization may cause.
Net-Zero Emissions:
- Balance the whole amount of greenhouse gases (GHGs) released and the amount removed from the atmosphere.

Carbon Neutrality vs. Net Zero Emissions vs. Climate Neutrality

Carbon Neutrality:
- Referring only to carbon emissions.
- Achieving carbon neutrality means reducing as many carbon dioxide ( $CO_2$ ) emissions as possible and then balancing those that cannot be eliminated through removals.
Net Zero Emissions:
- Getting to zero GHG through reduction in one's own emissions-related activities while removing additional GHGs from the atmosphere to make up any shortfalls, all in alignment with the targets outlined in the Paris Agreement.
Climate Neutrality:
- Reduction of all GHGs to the point of zero while eliminating all other negative environmental impacts that an organization may cause.

Examples of Carbon Neutral and Net-Zero Commitments

UN Environment: Climate neutral since January 2008 due to an offset program based on mitigation and purchase of Certificates of Emission Reduction.
Apple: Commitment to 100% carbon neutral across their entire value chain by 2030 through:
- Low carbon product design
- Expanding energy efficiency
- Renewable energy
- Process and material innovations
- Carbon removal
IKEA:
- Target: Halve emissions by 2030 and reach net-zero by 2050.
- Action: Reducing more emissions than it generates, addressing its full value chain.
- Circular Economy: Initiatives like the IKEA Preowned Program promote furniture reuse.
- Renewable Energy: 37% of IKEA’s suppliers use 100% renewable energy.
- Sustainable Transport: Part of the Zero Emissions Maritime Buyers Alliance.

Measuring Carbon Footprint

Definition: A measure of the amount of greenhouse gases (GHGs) emitted directly or indirectly by a person, product, event, company, or country.

Carbon Footprint of Activities

The size of the footprint depends on lifestyle choices, such as transportation, diet, and purchases.
Examples:
- Emissions from different modes of transport (domestic flight, long haul flight, car, bus, domestic rail, coach, Eurostar).
- Emissions per passenger per km travelled.
- Kilograms of greenhouse gas emissions per serving of different foods (beef, lamb, farmed prawns, chocolate, farmed fish, pork, chicken, cheese, beer, dairy milk, eggs, coffee, tofu, beans, nuts).

GHG Emission Scopes (Based on GHG Protocol)

Scope 1 (Direct Emissions):
- Emissions from sources owned or controlled by the reporting company.
- Examples: company facilities and vehicles.
Scope 2 (Indirect Emissions):
- Emissions from purchased electricity, steam, heating, and cooling for own use.
Scope 3 (Indirect Emissions):
- All other indirect emissions that occur in the value chain of the reporting company.
- Upstream activities: purchased goods & services, capital goods, fuel & energy-related activities, transportation & distribution, waste from operations, business travel, and employee commute.
- Downstream activities: transportation & distribution, processing of sold products, use of sold products, end-of-life treatment of sold products, investments, franchises, and leased assets.

Carbon Footprint Calculation Steps

Step 1: Scope Boundaries
- Define organizational boundaries (e.g., entire organization, process, product, or event).
- Choose a time duration.
- Example: Calculate the carbon footprint of a household of four for a particular month.
Step 2: Identify GHG Emission Sources
- Identify the activities and processes that result in GHG emissions.
- Example: Electricity and gas consumption, and transportation.
Step 3: Collect Activity Data
- Identify data requirements and preferred methods for data collection.
- Develop data collection procedures, tools, and guidance materials.
- Examples: Electricity bill for power Consumption, Gas bill for gas usage, Fuel receipts/distance travelled for daily commuting.
Step 4: Calculate GHG Emissions
- Involves converting activity data into GHG emissions using Emission Factors and Global Warming Potential.
- Emission Factor: A representative value that relates the quantity of a pollutant released into the atmosphere with an activity associated with the release of that pollutant.
Step 5: Summation of GHG Emissions
- Sum up all the GHG emissions from the different sources and activities.

Carbon Footprint Calculation Example

Step 3: Collect Activity Data
- Power consumption: 229 kWh (from electricity bill).
- Gas usage: 60 kWh (from gas bill).
- Daily commuting: 1100 km (via family car).
Step 4: Calculate GHG emissions
- Choose emissions factors.
- Singapore’s average Grid Emission Factor (GEF): 0.412 kgCO2/kWh in 2024.
Step 5: Conversion into CO2e and Summation of GHG Emissions
- Household Power: 229 kWh x 0.412 kgCO2e/kWh = 94.348 kg CO2e
- Household use of gas: 60 kWh x 0.1598 kgCO2/kWh = 9.588 kg CO2
- 60 kWh x 0.000018 kg CH₄/kWh =0.00108 kg CH₄
- 60 kWh x 0.00000036 kg N₂O/kWh= 0.0000216 kg N₂O
- Daily commuting: 1100 km x 0.14370 kgCO2e/km = 158.07 kgCO2e
- Total CO2 emissions = 262.042 kg CO2

Carbon Market

Definition: A trading system in which carbon offsets and carbon credits are sold and bought.
One tradable carbon offset or credit equals one tonne of carbon dioxide or the equivalent amount of a different greenhouse gas reduced, sequestered, or avoided.
Once a carbon offset or credit is purchased and the CO2 is emitted, that credit is “retired” and cannot be sold or used again.

Types of Carbon Markets

Compliance Markets:
- Mandatory systems created by governments to cap emissions for specific industries.
Voluntary Carbon Markets:
- System where carbon credits can be purchased by those who voluntarily want to offset their emissions.

Examples of Compliance Market: Emission Trading Systems (ETS)

Also known as “cap-and-trade.”
Regulated businesses or countries are issued allowances (i.e., emission permits) by governments.
Polluters that exceed their permitted emissions (i.e., over-emitters) must buy permits from others with permits available for sale (i.e., trade).
The European Union launched the world's first international ETS in 2005.

Voluntary Carbon Markets

Allow carbon emitters to offset their unavoidable emissions by purchasing carbon credits emitted by projects targeted at removing or reducing GHG from the atmosphere.
When a credit is used for this purpose, it becomes an offset.
Companies can participate in the voluntary carbon market either individually or as part of an industry-wide scheme.
Standards are organizations which certify that a particular project meets its stated objectives and its stated volume of emissions.
Standards have a series of methodologies, or requirements, for each type of carbon project.
Example Project: Improved Agricultural Land Management in Romania.
- Developer: Involtor Future Agriculture.
- Activities include reduced tillage, cover cropping, crop residue retention, optimized fertilization rates, and improved water management.