Reducing greenhouse-gas emissions will help to avert dangerous climate change, but it could also bring other benefits too. One major plus is the accompanying reduction in health-damaging air pollutants and precursor species, including particulate matter, nitrogen oxides and sulphur dioxide.
Until now little attention has been paid to these co-benefits when totting up the cost of climate-change mitigation, but new research shows that they could be substantial.
Gregory Nemet from the University of Wisconsin, US, and his colleagues surveyed previous studies and discovered that air-quality co-benefits are worth between $2 and $196 ($50 on average) for every tonne of carbon dioxide that is mopped up or not emitted in the first place. These values are similar to the estimated cost of climate-change mitigation measures, and show that climate-change mitigation could completely pay for itself. The findings are published in Environmental Research Letters.
"Co-benefits have the potential to offset all of the near-term costs of climate policy," Nemet told environmentalresearchweb. "They provide a very large effect and thus it's a very large mistake to ignore them."
So why is fresh air so valuable? The answer lies in the cost of cleaning up dirty air, and the problems that poor-quality air brings to society. Polluted air results in unhealthy people, animals and plants. This results in a direct cost to society, when people are unable to work, their life expectancy is reduced and they have a lower quality of life due to illness. What's more, the healthcare costs of looking after and treating these people can be high. The only way to avoid such problems is through expensive pollution controls; avoiding the air pollution in the first place is a much cheaper option.
Many developed countries have already learned this lesson the hard way and they have stringent air pollution restrictions in place. But for developing countries air pollution is still a big issue, meaning that they could be major beneficiaries of the air-quality co-benefits associated with climate-change mitigation measures. Developed countries still stand to gain too, with reduced pollution-control costs.
Nemet and colleagues argue that it is vital that air-quality co-benefits are included in policy debates, and added to the costing of climate-change policies. "Too much emphasis is placed on minimizing the costs of meeting pre-specified emission-reduction targets," he said. "If we were to have a fuller discussion of why we as a society adopt the emissions-reductions targets we do, that would open the door to a more inclusive discussion about these other benefits."
In addition the inclusion of air-quality co-benefits would ensure that we tackle the problem at source; placing more emphasis on reducing fossil-fuel emissions, and less on other approaches such as geo-engineering or avoiding deforestation. Difficult though it may be, it is time to put a value on fresh air.