Carbon Footprint and Trading Questions and Answers

Answer: A

Each gas is multiplied by its global warming potential so that methane, nitrous oxide and the fluorinated gases can be added to carbon dioxide on one scale. Reporting in tonnes of carbon rather than of the dioxide understates the figure by a factor of 3.67.

Answer: B

Correct answer: carbon dioxide over a stated period

Global warming potential expresses the warming caused by a mass of gas relative to the same mass of carbon dioxide, integrated over a chosen horizon - conventionally a hundred years. Carbon dioxide is therefore 1 by definition, methane about 28 and nitrous oxide about 265. The horizon matters greatly for short-lived gases: methane’s potential over twenty years is nearer 84 than 28.

Answer: C

Correct answer: owns or controls

Scope 1 covers direct emissions from sources the organisation owns or controls - fuel burnt in its own boilers, furnaces and vehicles, process emissions from its own plant, and fugitive releases such as refrigerant leakage. The test is control of the source, not ownership of the fuel or the site, and it is the boundary decision that determines what falls in scope 1 rather than elsewhere.

Answer: D

Correct answer: purchased electricity, heat or steam

Scope 2 covers indirect emissions from energy the organisation buys and consumes: electricity, and purchased heat, steam or cooling. The emissions occur at the generator’s stack rather than the buyer’s, but the buyer caused them by taking the energy. Scope 2 exists as a separate category because it is under the buyer’s influence through both consumption and procurement, which is why it is reported both ways.

Answer: A

Correct answer: value chain, upstream and downstream

Scope 3 covers every other indirect emission in the value chain - purchased goods and services, transport, business travel, commuting, waste, and downstream the use and disposal of the products sold. Fifteen categories are defined. It is the hardest to measure, since the data belong to other organisations, and for most companies it is by far the largest.

Answer: B

Correct answer: a retailer or a brand owner

A retailer burns little fuel and buys modest quantities of electricity, but everything it sells was made, transported, used and disposed of by someone else, and all of that falls in its scope 3 - commonly 90 per cent or more of the total. The heavy industrial cases are the reverse: a cement works, a steel plant and a power station have most of their emissions in scope 1, at their own stacks.

Answer: C

Correct answer: which emission sources are assigned to which scope

The two boundary decisions do different jobs. The organisational boundary settles which entities are consolidated into the inventory, by equity share or by control. The operational boundary then settles, for those entities, which sources fall into scope 1, which into scope 2 and which into scope 3. Confusing the two is the commonest error in setting an inventory up.

Answer: D

Correct answer: emissions in proportion to its ownership interest

Under the equity share approach the organisation accounts for a share of each entity’s emissions equal to its economic interest - 40 per cent of a joint venture in which it holds 40 per cent. The alternatives are the control approaches, financial or operational, under which an entity is either fully consolidated or excluded altogether. The choice changes the reported total and must be stated and applied consistently.

Answer: A

Litres of diesel, kilowatt hours or tonnes of clinker are multiplied by a factor to yield the emissions. The quality of an inventory rests largely on whether the factors used are appropriate to the fuel and the region.

Answer: B

Correct answer: the measured quantity of fuel, energy or material

An inventory is built by multiplying activity data by an emission factor:

The activity data are the physical quantities - litres of diesel, kilowatt hours, tonnes of steel, passenger kilometres - and the factor converts each to mass of carbon dioxide equivalent. The quality of the inventory rests chiefly on the quality of the activity data, since the factors are usually published.