Switching to clean energy would pay for itself almost immediately. Photo: Flickr.com/epSos.de/CC BY
Significant co-benefits can be realised for health, ecosystems and the economy by linking climate change policies with those for air pollution control and energy security.
Reducing our reliance on fossil fuels is necessary to stop global climate change. But it will also cut air pollution, thereby improving the protection of health and ecosystems, and it can improve energy security. The co-benefits of climate policy are getting increasing attention, not least since they also bring significant financial savings. Four examples of recent scientific studies on this topic are summarised below.
Switching to clean energy would pay for itself almost immediately, according to a study1 published recently in Nature Climate Change. This is because actions to reduce greenhouse gas emissions often also reduce co-emitted air pollutants, thus bringing co-benefits for air quality and human health. So reducing the burning of fossil fuels will cut air pollution, save lives and therefore money.
The co-benefits of global greenhouse gas (GHG) reductions on air quality and human health were simulated using a global atmospheric model and consistent future scenarios, and by including two mechanisms: reductions in co-emitted air pollutants, and the effects on air quality of slowing climate change.
Relative to the reference scenario, the GHG reduction scenario results in significant lowering in the concentrations of health-damaging particulate matter (PM2.5) and ozone. The global health co-benefits of GHG mitigation result in an estimated 0.5 million avoided premature deaths in 2030, increasing to 1.3 million in 2050, and to 2.2 million in 2100.
From estimates of how much society values a human life, it is deduced that investing in alternative energy supplies should be worth the cost. The global average marginal co-benefits of avoided mortality are US$50–380 per tonne of carbon dioxide (CO2), which exceed the marginal abatement costs for CO2 in 2030 and 2050, and are within the low range of costs in 2100. East Asian co-benefits are 10–70 times the marginal cost in 2030.
Note that the co-benefits are likely to be underestimated because some health impacts are not included, such as mortality to people younger than 30 years of age and morbidity effects of air pollutants. Moreover, reduced air pollution damage to ecosystems is not accounted for.
Overall, the conclusion offers a strong incentive to countries to start cutting back on fossil fuels as soon as possible, not least as the co-benefits of avoided air pollution mortality alone can justify substantial reductions in GHG emissions. Air quality and health co-benefits, especially as they are mainly local and near-term, can therefore provide strong additional motivation for transitioning to a low-carbon future.
Another study2, published in Climatic Change, points to the benefits of better integration between policies on climate change mitigation, air pollution control and energy security. Here, an integrated assessment model of the global energy system was used to develop and analyse different energy futures up to 2030.
It was shown that an early introduction of climate change mitigation measures, such as renewable energy sources and energy efficiency, would reduce both GHG emissions and air pollutant emissions and related health impacts. Although a strong climate policy could lead to increased spending, these costs could be partly offset by lower costs for air pollution control. According to the study, overall savings could amount to USD100–500 billion a year by 2030, i.e. almost half the level of today’s investments in the global energy system.
Improving energy efficiency and focussing on regionally sourced renewables will also benefit energy security by leading to lower imports of fuel, making countries less reliant on foreign supplies. Moreover, it will result in a more diverse energy mix and improve the resilience of national or regional energy systems. The study suggests that early spending on climate measures could save up to USD130 billion a year by 2030 that would otherwise had to have been invested in measures to achieve energy security.
Published in Global Environmental Change, the third study3 examines scenarios of outdoor and household air pollution and related health impacts in 2030, given different sets of policies on air pollution, climate change and access to clean cooking fuels.
It is estimated that up to 80 per cent of the global population is still exposed to levels of air pollution that far exceed the recommended air quality guideline established by the World Health Organisation (WHO) of no more than 10 micrograms per cubic metre (μg/m3) as an annual mean for PM2.5.
In developing countries, like those in South Asia and Africa, emissions from cooking stoves account for more than half of the PM emissions, and recent research has been looking into the public health and climate co-benefits of improved access to modern cooking fuels and stoves in developing countries.
From the scenario analysis it was found that by 2030 implementation of all current and planned air pollution legislation would be inadequate to meet the WHO guideline, with global population-weighted anthropogenic PM2.5 concentrations rising to 34 μg/m3, compared to 26 μg/m3 in 2005.
However, significant health improvements would result under scenarios where current and planned air pollution legislation are coupled with increased clean energy access for households. Even greater health improvements were seen under scenarios combining more stringent air pollution controls with enhanced energy access and climate change measures.
It was found that the direct costs of air pollution control are significantly reduced in the combined scenarios, as the fuel shifts and efficiency improvements resulting from climate policy measures limit the need for end-of-pipe technologies.
It is concluded that the greatest improvements in global air quality are achieved through a combination of stringent pollution control policies, climate change policies and improved energy access.
Conducted as part of the EU Climate Cost project, the fourth study4 assessed the impacts on air pollution of international climate change policies consistent with meeting the target of limiting global warming to below 2°C. To achieve this target, global CO2 emissions were reduced by 80 per cent by 2050.
As a result of the lower fossil fuel use in the climate scenario, emissions of air pollutants also came down – by 2050 the emissions of SO2, NOx and PM2.5 fell by 70, 60 and 30 per cent respectively, compared to the baseline scenario. These reductions would in turn cut global air pollution control costs by 54 per cent, equivalent to a cost saving of about €250 billion per year in 2050. Around one third of these financial benefits would occur in China
Specifically for the EU, energy efficiency improvements and phasing out of fossil fuel use needed to meet the climate target would halve air pollution control costs to about €35 billion per year in 2050.
In addition, the anticipated reductions in air pollutant emissions from climate policy measures would bring significant health and ecosystem benefits. For example in China, current ambient concentrations of PM are responsible for a loss in the average life expectancy of about 40 months. In the climate policy scenario, this figure would be halved by 2050.
1Co-benefits of mitigating global greenhouse gas emissions for future air quality and human health. J. J. West, S. J. Smith, R. A. Silva, V. Naik, Y. Zhang, Z. Adelman, M. M. Fry, S. Anenberg, L. W. Horowitz & J-F Lamarque. In Nature Climate Change 3 (September 2013) pp. 885–889.
2Climate policies can help resolve energy security and air pollution challenges. D. L. McCollum, V. Krey, K. Riahi, P. Kolp, A. Grubler, M. Makowski, N. Nakicenovic. In Climatic Change 119 (July 2013) pp. 479–494.
3Better air for better health: Forging synergies in policies for energy access, climate change and air pollution. S. Rao, S. Pachauri, F. Dentener, P. Kinney, Z. Klimont, K. Riahi, W. Schoepp. In Global Environmental Change Vol. 23, (October 2013) pp. 1122–1130.
4Co-benefits of post-2012 global climate mitigation politics. P. Rafaj, W. Schoepp, P. Russ, C. Heyes, M. Amann. In Mitigation and Adaptation Strategies for Global Change Vol. 18 (August 2013) pp. 801–824.