Calculate the human impact of your everyday decisions

Carbon calculators are everywhere but miss reporting on the human impact of climate change, which could drastically change how we think about making consumption choices

Wherever you look there seems to be a carbon calculator these days. Your favorite environmental organization websites will have them. You’ll encounter them in news outlets. We even see them in online stores, flight selectors and more. They have become a formal part of curricula in teaching children about sustainability.

There can be little doubt these tools have been useful for awareness about climate change, and still are. But they all seem to miss an important part of the narrative. The climate related lives lost due to our product consumption choices.

By framing the problem in terms of carbon emissions, we abstract the real impacts of climate change on people. It’s impact on us, our families, our communities. Those we care about. We miss communicating perhaps one of the strongest insights that might help us realize how our consumption patterns are impacting the world around us, and by extension our motivation to change.

At the Better Planet Laboratory at the University of Colorado, Boulder, we support change through the way we communicate, educate and raise awareness about climate change. And we believe in putting humans at the center.

The idea of calculating the human impact of climate change in the scientific community is not overtly new — there are many studies that have attempted to work out how many people will be negatively impacted through negative health impacts associated with climate change, including those who will have a reduced life expectancy because of climate impacts.

There have also been studies which work out the emissions associated with particular products, or services we consume, called Life Cycle Assessments. In these studies scientists are work out the different types of emissions for each step of a product or service creation to consumption or waste cycle.

But what has been missing is the link between these two fields of science, in a way that is easy to understand. It is this gap that got us thinking. Could we bridge this science together? So we started an experiment.

The result is what we call the Human Impact Calculator, a prototype algorithm that can tell you the how many minutes or seconds you are likely to take off someone else’s life due to emissions related to life choices, for example, the meals you eat, the mode of transport you take, or even the flight choices you make.

As part of a campaign to both raise awareness about the human impacts of climate change, but also understand how the public might respond to this new kind of tool, we have created a simple version for you to try out today. Give it a try and let us know what you think.

What you may have noticed is different products can have very different impacts. Take international flights for example — some flights are worse for the environment and also carry a greater human toll too.

There are some important things to note about these estimates. There are a wide range of estimates on climate impacts in the literature, so we have picked the central estimates of integrated deaths over 2020–2100, as a middle ground, and baseline warming of 2.4 °C by the end of the century, to which your emissions would surpass. These are likely underestimates. Like all other carbon calculators, we have also converted emissions into CO2 equivalents integrated over a 100 year lifetime — more fine tuned estimates require studies to map the lifetime of different species of greenhouse gas emissions and warming potentials for each product consumed, and for us to map those contributions to the emissions budgets against time dependent mortality. But we don’t use the full product life cycle impacts for items where this is problematic to avoid overestimating due to shorter lived species. If you are interested in the nitty gritty, stay tuned for a paper explaining more.

More than anything though, we hope that this starts a conversation. And we hope will lead to others to think creatively about how carbon calculators could be improved to include additional metrics surrounding human impacts and climate justice more broadly. If you have any feedback on this experimental project, we’d love to hear from you.