Worldwide annual CO2 emissions are about 35 billion tons and rising. So what difference does it make if I ride my bike to work every day to avoid 5 tons of emissions this year, or if decide not to make that family trip to Hawaii because of the 20 tons of CO2 it will emit? Even if I do make these sacrifices to reduce my carbon footprint, China’s emissions are increasing so fast that they will cancel my reductions out by a factor of millions. I might as well just live my life and hope that our governments deal with the problem, or that a new technology comes along just in time to save the day. And even if the Earth’s atmosphere becomes unlivable, there is nothing that I could have done about it.
Even for people deeply concerned about climate change, these attitudes are widespread and rational. Why make a personal sacrifice when its effect on overall climate is negligible? Even though my children and I would benefit from a cleaner atmosphere, we, and a billion other families, will get that benefit regardless of whether or not I personally “green up my act.”
Similar calculations are made by individuals, companies, industries, and countries the world over, and represent a major barrier to action on climate change. No one wants to sacrifice unless everyone else is sacrificing, and many would prefer to be a “free rider” on sacrifices made by others. Economists and social scientists refer to the refusal of individuals to give up a small individual benefit for a large collective benefit as a “collective action problem” or the “tragedy of the commons.”
Because of the widespread belief that the collective action problem makes voluntary approaches to carbon reduction impractical (or that focus on individual voluntary action will reduce pressure for institutional change), much of the focus on addressing carbon emissions has been on achieving global-level climate accords or national-level actions such as a federal carbon tax. These supra-national or national-level efforts promised to avoid the collective action problem by imposing binding quotas and restrictions by ensuring that the sacrifice is borne by all. Unfortunately, international climate negotiations and national carbon taxes have borne little fruit (in large part because of collective action problems occurring at the national and international levels.)