b'Education matters Education mattersfollowing is a very high level review ofare at least 5%, it is useful to consider the this excellent USA-centric course. flow of energy throughout the economy starting from primary energy sources As a precursor, I invite the reader toto the consumption by industries and consider the following three questions: end-users. For the USA, this flow is very complex. First addressed by Bridges (1) By how many times does the(1973), the energy flow across the USA in anthropogenic carbon flux exceed2018 has been visualised in Figure 2. The the sum of all the analogous naturalmain purpose of Figure 2 is to illustrate processes? the complexity rather than detailed (a) 10 times(b) 100 times(c) 1000 times analysis, and for motivated readers, an (2) Which of the following is closestinteractive version of Figure 2 (https://bit.to the half-life of CO 2in thely/3hHLoow) may be more instructive.troposphere? Each of the energy markets identified Marina Pervukhina(a) 1 year(b) 100 years(c) 1000 years in Figure 2 are discussed along with Associate Editor for Educationthe associated difference in prices for Marina.Pervukhina@csiro.au (3) What fraction of land (as a percentage of the total surface of the Earth)both fossil energy and renewables. Such would be required to run a futureeconomics terms such as levelised cost, Education about environmentallyenergy system using biofuelsthe cost of use of a single alternative friendly energy options technology only? throughout a powerplant lifespan, and (a) 5%(b) 20%(c) 50% cost of mitigation, the cost associated It seems that energy is never far fromwith the choice of cleaner energy source, the news, and at the time of writing twoare discussed in detail.The overarching goal of the course is stories were competing for attention. Theto audit energy resources available atAir pollution, climate change and land first of these (Australian Broadcastingthe current technological stage. Thefootprint are the main environmental Commission, 2021) concerns a Federallist of the energy alternatives containsimpacts of energy production. Air Government decision to support a newfossil energy, renewable energy (hydro,pollutants emitted from industrial gas-fired power station in Kurri Kurri inwind, biomass, and solar photovoltaic),activities such as lead, nitrogen oxides, NSW. At AUD$600M, this is a significantand alternative sources of energy. Thesulphur dioxide, carbon monoxide, ozone, investment. The second of the twoappraisal criteria include the price of theand particulate matter cause various major energy-related stories concernsenergy produced using this alternative,severe impacts on human health. The the release of the International Energyand associated environmental impacts,course explains how (USA) governmental Agencys (IEA) Net Zero by 2050 report.and the land footprint. Figure 1 comparesregulations have helped to reduce the (International Energy Agency, 2021). Athe power potential of different low- amount of these harmful pollutants in the headline finding of this report was that ifcarbon options for electricity productionatmosphere over the last few decades.global CO 2emissions are to be reducedunder various land-use constraints.to zero by 2050, consistent with effortsThe course contrasts the successful story to limit the long-term increase in averageAs energy is a commodity business andof pollutants reduction locally (in the global temperatures to 1.5 C, then theenergy inputs to developed economiesUSA and some other countries) with the energy industry would need to move towards renewable sources. Prima facie, these two stories would seem to be at odds, because the requirement for net-zero emissions means a reduction in the use of fossil fuels to around 20% of their current levels. How then to reconcile the rhetoric as scientific problems rapidly expand into economic and social domains?One route to such reconciliation is through education. Harvard Universitys edX course Energy within environmental constraints (https://bit.ly/3u5gDwp), one of a number of online education options introduced in Preview 210, may provide motivated readers with the background with which to ask the right questions and, in so doing, properly consider theFigure 1.Comparison of power potential for different low-carbon electricity production options. consequences of different choices. TheSource:HarvardX course Energy within environmental constraints (https://bit.ly/3u5gDwp)JUNE 2021 PREVIEW 36'