Greenhouse gas emissions remain on a steadily rising path despite policymakers' best efforts, an OECD report has warned. Nuclear was noted as a major mitigating technology, while governments were urged to avoid 'lock-in' to carbon-emitting generation.
The OECD study considered climate change, biodiversity, fresh water and the health impact of pollution. In the chapter on climate change, the body run by the governments of the world's more developed nations asked whether "current pledges are enough to limit average temperature increase to 2ºC." For this, atmospheric concentrations of CO2 need to be kept below 450 parts per million (ppm).
It was noted that energy-related carbon dioxide emissions reached a high of 30.6 billion tonnes in 2010 - the major share of the overall global total of 48.4 billion tonnes that year.
Under a baseline scenario, that assumed current pledges were kept by the governments of the world but no new ones made, total annual emissions in 2050 could be some 80.8 billion tonnes, with 52.8 billion coming from energy. While all seb-sectors of energy are set to expand significantly, the most dramatic growth is expected in power generation where emissions could grow from today's 13.0 billion tonnes to 27.5 billion tonnes as an 80% growth in demand is met.
This baseline scenario sees carbon concentrations reach 685 ppm in 2050 with an expected average temperature increase of between 3 and 6ºC.
The OECD called for more urgent action to be made for lasting reductions and on a quick scehdule. The world is becoming "locked in more strongly every year" to a high carbon future, it said, because some 80% of the emissions predicted for 2020 will come from power stations already operating or being built now. The only way to reverse this 'lock-in' will be to shut down the plants early or, potentially, retrofit carbon capture and storage equipment.
It is cost-effective to deploy the low-carbon power generation tools available now, said the report. The extra cost of fast action for lasting emissions reductions would reduce global GDP growth from 3.5% to 3.3% per year, and by 2050 this would have amounted to 5.5% of GDP. However, "delayed or only moderate action," such as the implementing the pledges made in Copenhagen and Cancun, or "waiting for better technologies to come onstream," would increase the total end cost by 50%.
Some of the key policy steps proposed in the report were to set clear and credible emissions targets, put a price on carbon and thereby deploy market mechanisms to incentivise change, and to reform fossil fuel support policies. Another was to begin serious work on adaptation to climate change effects that may now be inevitable.
Nuclear energy's role in all this was little discussed, and of the three energy mix scenarios put forward, one was based on the idea that no new reactors might be built after 2020, leaving a dwindling fleet. Another did consider the case that CCS proved impossible, giving nuclear a greater share, although renewables were assumed to make up about half of supply in most cases.
However, the baseline scenario of current policies saw a gradual increase of nuclear capacity from today's 382.9 GWe to 988.0 GWe in 2050, markedly different from the phase out scenario.
Researched and written
by World Nuclear News