In 2011 burning of fossil fuels provided 83% of mankind s energy resource while nuclear electric power provided 9%, and renewable energy 8% (1).

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1 Hierarchy of Global Energy Sources and Related Risks John Bushell January 2015 Abstract This paper reviews future energy resource options required to provide mankind with the energy to sustain a growing human population demanding increasing living standards. It examines three options: 1 Assuming that anthropogenic (manmade) global warming is occurring as presently predicted by 97% of the world s climate scientists; 2 Assuming that global warming is not occurring at all but that the currently observed global warming is a short-term phenomenon; 3 Assuming that global warming is occurring and that methods of sequestering or otherwise absorbing carbon dioxide are practical and cost-effective. Present Energy Supply When the first Industrial Revolution (fossil fuels) started in England in 1750 the world s human population was 700 million. Global population is currently exceeds 7 billion and is forecast by the United Nations to reach 9 billion by In 2011 burning of fossil fuels provided 83% of mankind s energy resource while nuclear electric power provided 9%, and renewable energy 8% (1). To support this population mankind presently needs primary energy and agricultural activities that produce 65% and 35% respectively of greenhouse gas (GHG) emissions. Continuing GHG emissions in a business as usual scenario has the potential to render our planet uninhabitable (see Climate Science, below). Primary energy is raw energy before conversion to useful energy (eg: through burning coal, creating steam and running an electricity generator, or building and operating a hydro-electricity plant (2). Chief sources and relative percentages of anthropogenic GHG emissions are as follows: Energy Emissions Electricity Generation 24% Industry 14% Transportation 14% Buildings 8% Other energy related 5% Non-Energy Emissions Land Use 18% Agriculture 14% Waste 3% Total 100% 1

2 This paper addresses the options to reduce Energy Emissions listed above to levels that will reduce GHG emissions to levels that will preserve the habitability of the planet. Critical GHGs are carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O). Methane degrades into CO 2 and water up to 12 years after its release to atmosphere. A third of CO 2 emissions remains in the atmosphere for 100 years, a fifth remains in the atmosphere for 1000 years after its release to atmosphere (3). The most pervasive GHG is water vapour that, in the form of clouds, both shield the earth from the sun s radiation and also traps heat generated by solar radiation. In 2010 mankind emitted 50.1 Billion tonnes CO 2 equivalent of greenhouse gasses, an average of 7.2 tonnes CO 2 equivalent per person (t CO 2 e. /pp) (4) (5). On a national basis the major emitters of GHGs in 2010 were just those countries that have developed advanced economies powered by the fossil fuel industry, including the following average per capita emissions: Australia 28 tonnes CO 2 equivalent per person United States of America 21.6 tonnes CO 2 equivalent per person Canada 21.3 tonnes CO 2 equivalent per person Developing countries by contrast: China 8.3 tonnes CO 2 equivalent per person India 2.26 tonnes CO 2 equivalent per person Future Energy Demand In 2004, burning of fossil fuels produced 374 exajoules (EJ) of primary energy at a cost of 26 Billion tonnes of CO 2 released to the atmosphere. If we including non-fossil fuel energy sources a total of 469 EJ of energy was produced in that year (6). Global energy demand in 2014 was approximately 500 EJ. Global demand for primary energy in 2030 is expected to be between 650 EJ to 890 EJ, a range of 30% to 78% increase over the 2014 demand (7). Climate Science The current (2013) situation is that, when compared with the Holocene (last 10,000 years) average, the present average atmospheric concentration of CO 2 is parts per million (116 parts per million, or 41% higher than at any time in the last 15 million years) and average atmospheric temperature is 0.8 C above (plus 5.3%) the Holocene average (8). The European Union has set a target of a maximum of 2 C average atmospheric temperature above the Holocene average which infers a CO 2 concentration of 450 parts per million (60% above the Holocene average). Since the 1997 Kyoto Protocol obtained consensus to reduce manmade GHGs by 80% by 2050, global emissions have increased and there is general climate science agreement that unless there is a concentrated effort to reduce these emissions this target temperature will be exceeded. Based on the volcano-induced CO 2 increase between 2

3 50 to 60 million years ago (which was much slower than the present rate of increase in this gas) even this plus 2 C scenario implies a sea level rise of many metres (9). Burning all fossil fuels would produce a different, practically uninhabitable, planet. (10) This action would release some 13,000 billion tonnes of carbon into the atmosphere which could increase CO 2 by 8 to 16 times and could raise global mean temperatures over land by 20 C and over 30 C at the poles. However, global warming of between 10 C to 12 C which can occur below 4.8 times the present CO 2 concentration, could result in a wet bulb temperature (allowing for humidity) in excess of 35 C across most of the planet. Such a temperature produces intolerable conditions for humans (and most animals) because they are unable to cool themselves (11). There is a general, scientifically agreed, target of a maximum of 350 parts per million CO 2 concentration in the atmosphere. The Potsdam Institute for Climate Impact advised in 2009 that 18 billion tonnes of CO 2 equivalent is the maximum steady state GHG emissions per year that mankind can afford; this is equal to 2 tonnes CO 2 equivalent per person per year (tco 2 e. /pp /py) on an assumed global population of 9 billion people (12). The Institute also advised in 2009 that the maximum amount of GHG emissions that mankind could afford to emit before this steady state needs to be achieved was 1 billion tonnes CO 2 equivalent in coupled with an expected average atmospheric warming of 2 C (13). However, in November 2012 since GHG emissions are still increasing the same Institute, together with the World Bank advised that this limit has been revised down to half a billion tonnes if average warming of 4 C is to be avoided (14). From an average anthropogenic GHG emission of 7.2 tco 2 e. /pp /py (p2) to 2 tco 2 e. /pp /py requires an 80% reduction in anthropogenic GHG emissions to be achieved. Since the lower figure will need to be achieved in the future when even more energy will be demanded by a population requiring an improved standard of living (as noted on page 2) the practical reduction from today s emissions intensity will be even greater than 80%. If zero emissions per unit of electricity generated or distance moved by the major users of fossil fuels, energy generation and transport about 38% reduction could be achieved and that still leaves over 42% of GHG emissions to be achieved from the other anthropogenic GHG emissions listed on page 1. Thus emissions reduction needs to be commenced across all sectors of the economy with the large volume / least-cost sectors being addressed first. Even if a significant decline in anthropogenic GHG emissions is achieved there is considerable uncertainty regarding the commencement of and subsequent sustained reduction in total atmospheric GHGs. This uncertainly is mainly related to the clearing of soot and other fossil fuel contaminate particles from the atmosphere (thus admitting more sunlight and heat) and the geographic distribution of ocean heat uptake (15). The challenge to reduce GHG emissions is therefore all encompassing and delay will only result in further, possibly irreversible, damage to Earth s environment. Options for Reducing GHGs To address the dramatic reductions in GHG emissions required we need to understand the comparable GHG emissions by various energy sources when generating electricity. Table 1 shows the range of comparable GHG emissions for differing electricity generation methods (all 3

4 emissions are measured in CO 2 equivalent). Note that within each fuel source there may be a range of emissions depending on the method of conversion of the fuel, the age and effectiveness of maintenance and operation of the plant. Table 1: Ranges of GHG Emissions per kwh Electricity Production (17) Minimum (kg CO 2 -equiv. /kwh) Maximum (kg CO 2 equiv. /kwh) Lignite (Brown Coal) Hard Coal Oil Industrial Gas Natural Gas Wood Cogeneration Photovoltaic Power Wind Power Nuclear Power Hydro-electric Power Data sourced from European and country specific sources, using a global warming potential of 100 years. Includes the full life cycle of electricity production, construction, operation, decommissioning. The performance of biofuels in reducing GHGs is highly variable and depends on a number of factors. For example: Indirect land use change from US corn ethanol expansion range from small, but not negligible, to several times greater than the life-cycle emissions from gasoline. Biofuels can achieve a 10% - 60% reduction in GHG emissions over the lifecycle when compared with coal electricity generation - but they still produce greenhouse gases when burnt (18). Survivability and Sustainability Achieving significant GHG emissions reductions quickly is therefore urgent and it is evident that the current business as usual primary energy generation scenario is untenable. In developing an acceptable energy generation plan are therefore two critical objectives to be addressed: Survivability and Sustainability. Survivability means avoiding a highly damaging average atmospheric warming in excess of 2 C and associated ocean warming, acidification and excessive sea level rise. Sustainability means the need bring global atmospheric (manmade) GHG emissions to a maximum of 350 parts per million (currently believed to allow a maximum budget of 18 Billion tonnes CO 2 equivalent per annum manmade GHG emissions) once this target has been achieved (16) (16.1). 4

5 Sustainability has received much attention in the popular press and in many scientific papers. However the evidence to date is that, on current projections, we may fail to achieve the first critical objective, survival, for millions of humans. The lifestyles of many others are likely to be negatively affected as dwindling access to food growing and housing resources result in increased conflict and costs necessary just to survive. Table 2 classifies existing and potential primary energy sources by the two critical objectives: Survivability and Sustainability. Table 2 also classifies known and anticipated energy resources by the: The estimated quantity of primary energy available in exajoules (EJ) is also shown either in total or per year (p.y.) in the case of renewable resources; The amount of greenhouse gas emissions produced; The currently known approximate resource life. It should be noted that there is considerable variation in the estimation of potential energy from all the sources quoted in Table 2. For example, there is considerable variation in estimates of remaining fossil fuel resources and reserves. The possible quantum of unconventional fossil fuel resources is separately identified in Table 2. The unsubsidised price of energy production will also impact on the quantum of a particular type of energy produced and consumed. This is particularly applicable to unconventional energy extraction costs and environmental damage as these are under constant review as the industries develop. By the same token the estimate for geothermal energy may be optimistic when practical heat extraction has to be implemented as there is a wide variety in the quantity of extractable energy available, it is subject to low heat flow through rock strata and eventual exhaustion in some areas (20). It is important to note that by no means all of the energy noted in Table 2 can be extracted and used. Some resources will be in such small quantities that it will be impossible to detect them, some will be impossible to extract and some, even with improved technology will be uneconomic to extract and utilise. Similarly with renewable energy an are may have good insolation for, say, 10 months per year an a monsoon for 2 months which severely restricts the efficacy of renewable energy equipment. Note that in Table 2, energy is classified initially by SOURCE and then by the Medium through which the energy is delivered. 5