Monthly Archives: January 2014


Co-benefits of climate action worth at least £85 billion in UK

Wide-ranging review finds benefits dominated by lifestyle change

A wide-ranging review has found that meeting carbon targets in the UK will provide at least £85 billion in health and environmental co-benefits up to 2030.

The report considered the impacts of action to meet the UK’s fourth carbon budget, for the period 2023-27. This is a step on the path towards cutting carbon emissions by 80% by 2050 (from 1990 levels). After an extensive review of existing studies and literature, the consultants identified a wide range of both positive and negative impacts, which were quantified where possible.

The results are quite surprising. As expected, positive impacts (co-benefits) include the air quality benefits of reduced fossil fuel combustion. The health benefit of reduced exposure to fine particle (PM2.5) pollution was estimated as around £1 billion per year in 2030. Yet even greater benefits arise from a shift to healthier lifestyles. The health benefits of walking and cycling instead of driving are estimated as £2.3 billion in 2030, reflecting the importance of active lifestyles in reducing chronic illnesses such as heart disease and diabetes. There are even greater benefits through cutting traffic congestion, saving £8.4 billion in lost time.

Some negative impacts were also identified, including waste disposal and accident risk for nuclear power. The total impacts that were quantified reached around £13 billion per year by 2030, with a net present value of £85 billion over the period 2008 to 2030 (at an annual discount rate of 3.5%). However, the researchers stress that this is an incomplete estimate as not all impacts could be quantified.

An extra scenario in which consumption of meat and dairy produce was halved was also evaluated. This produced health benefits worth an estimated £11 billion per year in 2030, through reducing the intake of saturated fat, though the authors note that there is considerable uncertainty attached to this estimate.

Forster, D., Korkeala, O., Warmington, J., Holland, M. and Smith, A. (2013) Review of the impacts of carbon budget measures on human health and the environment. Report to the Committee on Climate Change. Harwell, Oxfordshire, UK: Ricardo-AEA and EMRC.



Climate policy boosts energy security

Low carbon scenarios increase diversity and reduce energy trade

A new study shows that climate action improves energy security, as energy demand declines and low carbon renewable and nuclear energy displaces imported oil and gas.

Jessica Jewell of IIASA and her co-authors found that under a baseline scenario, global energy trade soars from 100 exajoules (EJ) per year today to 400 EJ in 2100. Over-reliance on imported energy could expose many countries to risk of supply disruption or price shocks, especially as oil and gas exports will continue to be dominated by a small number of countries. But under a range of low-carbon scenarios energy trade is much lower, varying from 40 to 240 EJ/yr in 2100. This is partly due to lower energy demand, and partly to replacement of imported fossil fuels with locally produced renewable and nuclear energy. In the baseline scenario, the proportion of the global primary energy supply that is traded remains at around 20%, but in the scenarios with unlimited penetration of renewables it falls to as little as 3%.

There are interesting differences between the 42 different low carbon scenarios. All are taken from the Global Energy Assessment, and all restrict future temperature rise to 2oC over pre-industrial levels. However, the greatest energy security benefits arise in the scenarios that focus on energy efficiency rather than energy supply. These scenarios see energy demand fall steeply, reducing the need to import energy and making the economy less sensitive to global energy price fluctuations.

The lowest energy trade occurs in a high efficiency scenario in which there is a significant switch to electric and hydrogen vehicles, and no restriction on the uptake of renewable or nuclear energy. Interestingly, restrictions on the uptake of carbon capture and storage (CCS) tend to improve energy security, as this forces a move away from fossil fuels.

The most striking impacts are seen in global oil trade. Under the baseline, this rises from around 80 EJ/yr today to a staggering 180 EJ in 2100 – a major security risk, given that the transport sector is almost totally dependent on oil. Yet in all the low carbon scenarios, oil trade plummets dramatically to under 10 EJ/yr by 2100. Trade in gas and coal is also lower in the low carbon scenarios than in the baseline, with the exception of a few scenarios where the use of renewables is restricted.

Trade in biofuels increases in all scenarios, including the baseline, yet it remains at well under half the volume of oil traded at present. In some scenarios, however, trade in hydrogen becomes comparable with present day oil trade by the end of the century. But both biofuels and hydrogen are exported from a greater range of countries than oil and gas, meaning that supply risks are lower. The exception to this is a few scenarios that restrict nuclear energy, as this limits the number of countries that can generate enough electricity to produce hydrogen, e.g. by electrolysis of seawater.

The paper concludes that low carbon scenarios generally lead to lower energy trade and higher energy diversity, especially where the focus is on reducing energy demand, though in some scenarios a high penetration of solar power by the end of the century does reduce the diversity of the electricity supply mix.

Areas for future study could include analysis of other aspects of energy security that were not included in the model, such as resource depletion (for oil and gas), ageing infrastructure and spare electricity generation capacity.

Energy security under de-carbonization scenarios: An assessment framework and evaluation under different technology and policy choices. Jessica Jewell, Aleh Cherp and Keywan Riahi. Energy Policy. 65 (2014) 743-760.