Green Parties are often at the forefront of political support for Citizen’s Basic Income: but is this rational? At the heart of the Green Party’s concerns is protection of the environment, which in today’s context means reducing carbon dioxide emissions in order to control climate change. So the question to be asked is this: Is there a connection between Citizen’s Basic Income and reducing carbon emissions?
The answer to that is not simple. A Citizen’s Basic Income could have all manner of different effects depending on the details of the particular Citizen’s Basic Income scheme: that is, the levels at which it would be paid, and the ways in which it would be funded. For instance, to implement any change that would reduce inequality might increase carbon emissions.
We have to say ‘might’ here because the effects of reducing inequality could be ambiguous. High inequality fuels status competition and therefore consumption, so to reduce inequality could reduce consumption and therefore reduce carbon emissions. However, poorer households have a greater propensity to consume products the production of which raises carbon emissions, whereas wealthier people have a greater propensity to consume cultural and other goods that produce lower carbon emissions. This means that if household incomes were to become equal then carbon emissions would rise.  Where the balance would fall between these two opposite tendencies will be difficult to say until inequality is reduced and we find out.
But of course it would not be the Citizen’s Basic Income itself that would increase carbon emissions as inequality fell: it would be the inequality-reducing funding mechanism that would do so.
On the other hand, the Belgian Green Party proposes that a Citizen’s Basic Income should be partially funded by ‘higher taxes on consumption, cars, pollution, and financial revenues, and less on labour’. This would reduce carbon emissions. But again – it would not be the Citizen’s Basic Income that would reduce carbon emissions: it would be the funding mechanism.
There are many good arguments for Citizen’s Basic Income, but reducing carbon emissions is not one of them. The connection is different. The reduction of carbon emissions must be one of the tests for a Citizen’s Basic Income scheme. It must function as a constraint, not as a reason.
 Kate Raworth, Doughnut Economics: Seven ways to think like a 21st –century economist, London: Random House, 2017, p. 172; Lutz Sager, Income Inequality and Carbon Consumption: Evidence from environmental Engel curves, Grantham Research Institute on Climate Change and the Environment, 2017