Climate change 2013: IPCC report no. 5 & the nuclear debate renewed

Climate Change 2013: The Physical Science Basis

At the end of September this year, the Intergovernmental Panel on Climate Change released their latest summary on the scientific, technical and socio-economic aspects of climate change.  The first document of the 5th IPCC assessment report (AR5) , to use its full catchy title, is called:

The IPCC Work Group 1 Fifth Assessment Report Summary for Policy Makers – Climate Change 2013: The Physical Science Basis

Headline statements from the technical summary can be found here, making it easy for those of us who aren’t across the technical details of climate science and modelling, and/or are too lazy to try (it’s only 2 pages long!). Some of the major statements in this document include:

  • Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.

  • The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence). Over the period 1901 to 2010, global mean sea level rose by 0.19 [0.17 to 0.21] m.

  • Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped. This represents a substantial multi-century climate change commitment created by past, present and future emissions of CO2.

These statements confirm in no uncertain terms the unequivocal threat of climate change to our home planet. The report also challenges any remaining sceptics by concluding that it is extremely likely that human influence has been the dominant cause of observed warming since 1950, with the level of confidence having increased since the fourth IPCC assessment report.

Another recent challenge to climate change sceptics came in the form of an open letter from the international scientific community written in 2011. Signatories to the letter include Professors and Doctors from universities and research organisations across Australia, NZ, Fiji, Canada and the US including: Australian National University, University of Western Australia, University of New South Wales, University of Melbourne, University of Adelaide, University of Queensland, Monash University, Macquarie University, Curtin University, CSIRO (post-retirement), Victoria University of Wellington, the American Physical Society, University of Ottawa, University of the South Pacific and the Great Barrier Reef Marine Park Authority.

It doesn’t mess about, with the first two sentences telling us that:

“The overwhelming scientific evidence tells us that human greenhouse gas emissions are resulting in climate changes that cannot be explained by natural causes. Climate change is real, we are causing it, and it is happening right now.”

The letter then continues to condemn online sceptics and the media:

“Aided by a pervasive media culture that often considers peer-reviewed scientific evidence to be in need of “balance” by internet bloggers, this has enabled so-called “sceptics” to find a captive audience while largely escaping scrutiny.”

And concludes with a responsibility-laden statement that:

“The individuals who deny the balance of scientific evidence on climate change will impose a heavy future burden on Australians if their unsupported opinions are given undue credence.”

While Australia is looking set to become the very first country in the world to dismantle a carbon pricing mechanismover 30 countries have introduced a market-based mechanism with a legal limit on carbon pollution via an emissions trading scheme. This includes the European Union (nation-based), US (state-based: California), South Korea, Japan and China (state-based).

However, the question of whether economic mechanisms will be enough to keep the world’s temperature from rising more than 2C over pre-industrial levels has resurrected a the debate over a controversial option which some had probably thought would never again seen the light of day: the use of nuclear power.

Scientists at The Conversation state that wind turbines and solar panels combined currently deliver only around 3% of total electricity consumption in Australia and that the contribution of renewable energy has decreased over time – from 19% in 1960 (mostly due to the use of hydropower) to 9% today. Recently, four top climate and energy scientists (Dr James Hansen, Dr Ken Caldeira, Dr Kerry Emanuel and Dr Tom Wigley) called on world leaders to support development of safer nuclear power systems arguing in an open letter that:

“As climate and energy scientists concerned with global climate change, we are writing to urge you to advocate the development and deployment of safer nuclear energy systems…….. Renewables like wind and solar and biomass will certainly play roles in a future energy economy, but those energy sources cannot scale up fast enough to deliver cheap and reliable power at the scale the global economy requires………While there will be no single technological silver bullet, the time has come for those who take the threat of global warming seriously to embrace the development and deployment of safer nuclear power systems as one among several technologies that will be essential to any credible effort to develop an energy system that does not rely on using the atmosphere as a waste dump.”

Another source of information challenging the traditional environmental position on nuclear power and assisting to reignite the nuclear power debate is Pandora’s Promise. It is a 2013 documentary directed by Robert Stone which argues that nuclear power is actually a relatively safe and clean energy source which can help mitigate the serious problem of anthropogenic global warming.

However, some argue that the film hypes the promise of advanced nuclear technology, over-stating the positives and under-playing the negatives including the possible future use of the latest technology, ‘fast reactors‘. These reactors could potentially provide a sustainable source of energy while reducing the total radiotoxicity of nuclear waste and dramatically reducing the waste’s lifetime. But some scientists argue that they are inherently more unstable and dangerous than reactors currently utilising low-enriched uranium, and also require fuels made from plutonium or “highly enriched” uranium that can be used to make nuclear weapons.

The ultimate question in this debate may be: Do the risks associated with the use of nuclear power outweigh the risks and current health effects of coal-fired power?

Recent research suggest that coal and gas are far more harmful than nuclear power, with coal-fired power generation currently contributing to approximately 1.3 million death per year .

NASA: Mean net deaths prevented annually by nuclear power between 1971-2009 for various countries/regions. (Source:

In addition, the consequences of human-induced climate change as a result of fossil fuel burning are expected to have multiple direct and indirect impacts on our lives, as stated many times over by the IPCC.

Given that it is widely understood that climate change and its consequences are STILL increasingly critical issues on a global scale, is it time for environmentalists to separate themselves from the anti-nuclear movement and encourage the wider community to embrace nuclear power as a major source of energy generation?