Clear Standards' Carbon Tracker app for the iPhone

Upon launching the app you’ll notice three main icons at the bottom, each representing a distinct aspect of the Carbon Tracker system. The first window presented to you is the 'Home' screen. Here, your CO2 'Goal' for the current month is represented as a number in either kilograms or pounds, either one of which you can select from the About tab. This number is accompanied by a green bar showing its relative size, below which is your Actual CO2 output and a red bar. The length of each bar is relative to the other. So a disproportionate Actual amount of emissions is represented by a large red bar and a diminished green one. This is also visually depicted in a 12-month graph on the same screen.

Of the two variables, emissions targets are left entirely up to you, which is kind of shame. For although I would consider myself an environmentally conscientious individual, I had no clue what the ideal amount of CO2 emissions for an average individual was. Rest assured, after downloading the app, I did my research and as it turns out various sources cite an ideal of 2 tons of CO2 per person per year. That’s approximately 84kg/per month (or 182 pounds). Simple enough to find but it would haven been a pertinent snippet of information for the developer's include.

As for the measurement of 'Actual' emissions, the Carbon Tracker uses an activities system to based on various modes of transportation to calculate the total number. Tapping on the 'Activies' tab brings up a form not unlike that of the Calendar app, except this time, once you’ve selected the date, you proceed to identify what mode of transportation you took and how far you traveled. The app covers air travel, automobile (by size: small, medium, and large), bus, and commuter rail. Each mode has an assigned amount of CO2 emissions per kilometre/mile, as set out by the World Resource Institute. If you’re not into calculating just how far you’re going to be riding the bus, the app can also make use of the GPS feature to record the distance traveled.

As you input your daily travels, the CO2 accumulates and you begin to get a real feel for the impact of, say, a 25 kilometer commute in a medium sized car (5kg of CO2) versus a bus (1kg of CO2). Add that up over a month and the difference is sobering. While there is no auto-fill option, a significant drawback given the often repetitive nature of commuting, you can simply calculate the average distance per week or month and enter that number in as a single event.

You can, however, quickly manage your monthly targets on the Goals tab. These can be set to variously levels but should be done so after determining your current output. That way you can slowly wean yourself onto more environmentally sound methods of travel. Or if you’re determined, you could set them all to 83 kilograms from day one and see how well you can reform your ways.