Publication Name

KICK THE HABIT

THE CYCLE – COUNT AND ANALYSE

much you need invest to have those emissions reduced somewhere else.

So, if you simply want to know what will be the emissions from a specific

flight or household operation, they will be quite helpful. The Tufts Climate

Institute recommended four companies and their calculators: Myclimate,

Climate Friendly, Native Energy and Atmosfair.

The latter is appreciated for estimating emissions from flying which is quite a

complex procedure. Factors a good calculator takes into account for flying in-

clude the type of ticket (economy passengers generate lower emissions than

business or first class ones, because they account for less weight per unit of

fuel burnt for each passenger), model of plane (more modern aircraft are

more fuel-efficient), occupancy rate (the fewer empty seats there are, the less

wasteful empty space is being flown around the world) and the flight distance

(a substantial share of the GHG emissions generated from a flight occur dur-

ing take-off and landing, so longer distance flights are more GHG efficient

per unit of distance, and non-stop flights are more GHG efficient than indi-

rect flights). Even if you might not be able to account for this in your calcula-

tions, be aware that the total warming effect of your flight is higher than just

what is attributed to CO

emissions directly. There are other emissions from

aviation apart from CO

, such as nitrogen oxides and water vapour, and CO

emitted at high altitude has an enhanced warming effect.

Varying outcomes

Whichever climate calculator you decide to use, you need to remember that

there are sometimes huge variations between their conclusions – not surpris-

ing when you remember that they often start fromquite different assumptions.

One calculator, for example, estimated the emissions from a return flight

from a European capital to Tokyo at 15.66 tonnes, another at 1.71 tonnes.

Find your own

Before choosing one particular calculator as being best suited to your needs,

it is probably worth trying several and comparing their results. Do they

explain, in terms you can understand, how they reach their conclusions?

What factors does the calculator include, and what does it omit: food, lei-

sure, consumption, transportation? Are the questions the calculator asks

you detailed enough to produce useful and honest results, rather than just

relying on your rose-tinted view of your own behaviour to give you the an-

swers it thinks you want, not the ones you need?