A ‘Fair Share’ Approach to Individual Carbon Emissions

16 September 2019  |  BY Daniel Burkett, UNSW  |  Do My Actions Make a Difference?


A lot has been said about the moral obligations of states, sub-state actors (such as local governments), and industries to curb their carbon emissions. It might seem that this would entail a similar obligation for us, as individuals, to address our own personal emissions. But how might we argue for this?

Causing Harm

One of the simplest ways to point out the moral wrongness of an action is to show that it causes harm. This is based on the principle that (all other things being equal) we have a moral obligation not to perform an act that causes harm to others. In order to use this as a basis for the moral wrongness of our excessive personal carbon emissions, we have to show that some human or animal is directly harmed—or harmed more—by those emissions. This, however, does not appear to be the case. Suppose I go for a frivolous Sunday drive in my gas-guzzling SUV. If harm is what matters, then my personal carbon emissions on that particular drive do not make climate change worse: No human or animal suffers more from the effects of climate change than they already would have. To use a vivid illustration provided by Walter Sinnott-Armstrong, going for a Sunday joyride in a gas-guzzler—like any high-emission individual activity—is like pouring a quart of water into a river that is already going to flood downstream due to extreme rains.


An alternative approach is to claim that excessive individual emissions are unfair because they amount to “free-riding”. Free-riding occurs when someone takes advantage of a good without paying, while relying for the existence of that good on others’ willingness to pay. If I evade my taxes, but then make use of the public services for which those taxes pay (roads, schools, healthcare, etc.) I am free-riding, and therefore engaging in behaviour that is unfair, and—for this reason—morally wrong. Does this better describe what’s going on when we produce excessive individual emissions? It seems not. The ‘good’ that is achieved by reducing individual emissions—thus mitigating the worst effects of climate change—is the eventual return to a more balanced climate system. But this will take many years to achieve. So, while a gas-guzzling joyrider may fail to share the burden of a particular collective action, she does not unfairly enjoy the benefits of that collective action, because those benefits will only occur long after she is gone.

Taking More Than Your Fair Share

An alternative approach is to see emittable carbon as a scarce communal resource.  In order to avoid the most catastrophic effects of climate change, the global temperature increase must be kept below a certain level. Doing this will require that our total carbon emissions are capped. After taking historical emissions into account, we are left with a remaining—finite—carbon budget representing the total carbon emissions we can create while avoiding catastrophic climate change. Once we recognise these emissions as a scarce communal resource we must, by necessity, engage in rationing. It then becomes a simple case of looking to whether or not any individual is emitting more than their ‘fair share’ of those emissions. It’s precisely the same approach we might take when there is a scarcity of food, water, or medical supplies. When such resources are rationed, the immorality of taking more than your fair share isn’t based on the fact that you might be harming  others (though you might be), or that you are free-riding (though this may be the case), but merely in the fact that you are exceeding your own fair allocation.

Our Fair Share of Carbon Emissions

So how do our actual carbon emission levels match with our ‘fair share’ allocation? In 2015, nearly all countries agreed to limit the global average temperature rise to no more than 2°C compared to preindustrial levels—the maximum global temperature rise we can tolerate while avoiding the most catastrophic effect of climate changes. The attainment of this target requires that our emissions peak around 2020, drop 50% by 2045, and fall below zero by 2075. CarbonBrief.org provides a breakdown of individual carbon budgets based on this timeline. On their analysis, a child born in Australia in 2014 will have a lifetime carbon budget of approximately 458 tonnes of CO2, or—using their estimated 85-year lifespan—5.39 tonnes of CO2 per year in order to keep to the 2°C target.

How does this compare to our actual individual emissions? In 2014 (the most recent year for which full data is available) the carbon emissions per capita in Australia was 15.37 tonnes of CO2 per person—almost triple the proposed ‘fair share’ above. Assuming this trend continues, this means that an individual born in 2014 will have used up their lifetime ‘fair share’ of carbon emissions before their thirtieth birthday. In Late 2018, the IPCC issued a new report, revising the necessary maximum temperature to 1.5°C —not 2°C. This will massively reduce the total carbon budget we have available to divide among individuals. In order to meet this new target, an individual born in Australia in 2014 will only have a lifetime budget of 249 tonnes of CO2, or 2.92 tonnes of CO2 per year. At current rates, an individual will use up this lifetime budget before even leaving high school.

While some portion of these per capita carbon emissions will come from sources outside of our control (such as those created by industry), the portion over which we do have control is significant. The average Australian household uses 7227kWh of electricity per year – or roughly 2691kWh per person. That’s 0.83 tonnes of CO2.* If you eat a meat-filled diet, then the food you consume in a year exhausts about 2.6 tonnes of your carbon budget. Australians drive an average of 15,530km per year – that’s around 2.85 tonnes of CO2 in an average petrol-powered sedan.* Thus, the average Australian will still be consuming more than double their fair share of emittable carbon on the basis of their power, food, and transport emissions alone (6.28 tonnes of CO2 expended versus a 2.92 tonne budget). Even those who eat entirely vegan fare (reducing their emissions by 1.5 tonnes of CO2 per year*) and travel exclusively by bus (reducing their emissions by 1.28 tonnes of CO2 per year*) still come in over budget (at 3.5 tonnes of CO2 expended). If you opt to have a child, then any hope of remaining under-budget is entirely forfeit.

Does this mean that we should severely reduce our food consumption, abandon motorised transport, and give up on having children? Not necessarily. What it does mean is that we need to seriously reconsider how we live, how we consume, how we travel, and – yes – even how we reproduce. It’s no longer enough to say that, in the grand scheme of things, our personal carbon emissions make no difference. Nor is it acceptable to claim that we are already doing our part by washing our clothes in cold water (a reduction of 0.247 tonnes of CO2 per year), recycling (reducing our emissions by 0.2125 tonnes of CO2 per year), or upgrading our lightbulbs (a reduction of 0.10 tonnes of CO2 per year). While such measures are important, they must be coupled with far greater behavioural adaptations. Because the upshot is simple: Each of us in the developed world is currently producing far more than our fair share of carbon emissions. In this way, we are treating other members of our global community unfairly and, for this reason, are in breach of our moral obligations regarding how we should treat others.

*Figures calculated via Carbon Footprint.


Cullity, Garrett (2015). “Acts, Omissions, Emissions”, in Jeremy Moss (ed.), Climate Change and Justice (Cambridge, UK: Cambridge University Press), pp. 148-164.

International Panel on Climate Change (2018). Global Warming of 1.5°. <https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Full_Report_High_Res.pdf>.

Sinnott-Armstrong, Walter (2005). “It’s Not My Fault: Global Warming and individual Moral Obligations”, in Walter Sinnott-Armstrong & R. B. Howarth (eds.), Perspectives on Climate Change: Science, Economics, Politics, Ethics. Advances in the Economics of Environmental Resources (Amsterdam: Elsevier), Vol. V, pp. 285-307.

United Nations (2015). United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement <https://unfccc.int/sites/default/files/english_paris_agreement.pdf>.

Wynes, Seth & Kimberley A Nicholas (2017). “The Climate Mitigation Gap: Education and Government Recommendations Miss the Most Effective Individual Actions”, Environmental Research Letters 12.