As international leaders meet in Glasgow to discuss cutting carbon emissions, Emeritus Professor Ralph Cooney argues that the world needs to face up to five big questions about its future energy needs.
The important role of the COP26 climate conference in Glasgow this week will be to convince nations that continue to be hesitant about or ignorant of the looming climate threat to set genuine zero carbon target dates - and then lock these targets down with binding legislation.
About 100 countries have already set zero carbon targets but only about a dozen nations have also locked in their target with legislation. Aotearoa is one nation that has done so. However, there are many well-informed observers in this country who feel that our current climate strategies and targets are far too timid.
Here are five questions relating to energy sources that we all need to consider seriously if we are to re-establish a liveable climate.
The Bill Gates question: Coal or Nuclear?
The three fastest-growing greenhouse gas-emitting economies, China, India and the US, must achieve a low carbon status by 2050-2060. If they fail to do so, then the combined zero carbon targets and strategies of the remainder of the world may not be sufficient to avoid a slowly emerging massive climate catastrophe.
It has been suggested by Bill Gates and others, that this dilemma includes a choice between new nuclear and coal. Nuclear power, despite its troubling history and unresolved waste issues, does not produce greenhouse gases.
China has committed to doubling the number of nuclear power stations (to 100) by 2030 to enable a shift away from coal. China is also a leader in the production of renewable technologies including electric cars and is developing a full range of renewable energy sources.
India, which is dependent on coal to continue its economic development, is seeking a "silver bullet" energy technology to shift away from coal. This involves the development of novel thorium reactors which involve a costly neutron accelerator but unlike uranium fission reactors, cannot lead to nuclear weapon development.
India has the largest thorium mineral resources on the planet and has an operating thorium reactor prototype. There are 32 other countries with an interest in the development of thorium reactors.
The Biden administration has reversed the previous position of the US on climate action but making this a reality is being vetoed by the deeply divided nature of government in the US at present. This is despite the recent Pew Research poll showing that two-thirds of the US population want the Government to do much more to curb climate change.
Finally, it should be noted that even a single large nuclear reactor would not be practical in Aotearoa because it would oversupply the national grid and hence raise major contingency issues.
Will small nuclear reactors play a role?
The development of safer Small Modular Reactors (SMRs) by private companies (Westinghouse, Rolls-Royce etc) in the US, Britain and Canada, will have the capacity to power a small town and seem likely to play a role in these countries.
SMRs are less likely to play a role in Aotearoa because we already have a high proportion of renewable energy. Nevertheless, it would be prudent for Aotearoa to better understand this new era of small nuclear.
For example, SMRs might provide contingency bridging power when drought impacts on our hydropower. Powering a city of almost 2 million (Auckland), for example, would require about a dozen of these SMRs.
Despite the improved safety claimed for these smaller SMRs, issues like capital costs and the risks of transporting nuclear fuel and waste across oceans would need to be carefully considered.
In a separate development, light atom fusion reactors, which have been in development for decades and which promise an almost endless supply of clean power are now thought to be approaching practicality.
Can we make solar energy cheaper?
A second challenge is the development of energy sources and energy storage. Even relatively mature technologies such as solar and wind energy continue to be refined.
The World Economic Forum (WEF) has recently reviewed the development of energy-optimised split hybrid photovoltaic panels, large floating islands of photovoltaics at sea and photovoltaic skins covering all exposed architectural surfaces of buildings.
These developments will ensure that the sharp reduction in cost of solar energy in recent years will continue for some time.
How do we resolve scarce elements for batteries and devices?
The rapidly expanding demand for more efficient power sources for electric vehicles, electric planes and electric vessels is being addressed by a major global research drive.
This research is mainly focused on new improved batteries, and faster-release novel super-capacitors which involve physical diffusion rather than reactions.
The dominant battery type for the new electric age is the lithium-ion battery, the future of which is limited by the global availability of the element lithium. Other electronic devices and processes, which are critical to the future of renewable energy, are also limited by component element availability.
There are substantial unexploited reserves of lithium (Australia and Chile), cobalt (Democratic Republic of Congo and Australia) and thorium (India, the US and Australia) which are likely to be important in the future given that both of these strategic elements are in limited economic supply at present.
In terms of the Circular Economy strategy being led by a group of about 100 major international companies, the development of technologies for recycling batteries (and electric vehicles) has started, but still has a distance to go.
Will we need geoengineering?
Reducing emissions by itself may not be sufficient to solve climate warming and geoengineering of the atmosphere will need to be re-evaluated.
Paul Crutzen, 1996 Nobel Prize winner in chemistry, developed a refined climate cooling model based on the 0.5C cooling caused by reflection of solar energy by sulphuric acid droplets formed during the Pinatubo eruption in 1991.
Crutzen developed quantitative models for injecting minute particles of sulphate into the upper atmosphere to induce cooling.
Geoengineering was omitted from the 2021 International Panel on Climate Change (IPCC) report, after being featured in previous reports.
Another practical process for reduction of carbon dioxide is sequestration which converts the atmospheric carbon dioxide into carbonate rock. This has recently been developed on a large industrial scale in Iceland.
However, the scale of the atmospheric carbon dioxide problem suggests that such sequestration, while valuable, may be limited to a supportive role.
Don't forget the cows
Finally, Aotearoa has its own unresolved climate issues: the agricultural methane reduction target is too timid and a focused national research programme in partnership with other dairy-producing countries should be adopted to explore and expand the range of innovative solutions.
Secondly, new safe agents for the reduction of nitrous oxide, which is a potent climate warming gas in our pastoral sectors, needs to be progressed via research.
These and other problems should be able to be resolved and new economic opportunities created if the innovative research genius of Aotearoa can be fully harnessed. This is an important leadership role for the Government.
Ralph Cooney is Emeritus Professor of chemistry and former dean of science at the University of Auckland and a former director of the Ministry of Business Innovation & Employment research programmes.