Final thoughts

Having gained what small insights I have over the course of running this page, I remain fundamentally optimistic about the ability of human innovation, coupled with political impetus, to succeed in the challenge of ditching fossil fuels. Even as planet Earth nears a dangerous climate tipping-point, and with the now-tangible effects of anthropogenic climate change increasing in magnitude, encouraging news irrepressibly flows in from expected and unexpected places. It would appear that, despite recent high-profile setbacks, that the governments of the world, continually nudged by broad international consensus and successful international agreements, are getting a grip on the problem.

Recent high-profile setbacks...

I also remain, however, torn. On the one hand it would appear that a perfectly viable, practicable, established solution to the competing demands of reducing GHG emissions and increasing energy consumption has been there all along in the form of nuclear power. Eric Jeffs' compelling analysis emphasises the undeniable fact that nuclear power is the only established means of providing fossil-fuel-comparable generating capacity with zero GHG emissions. Yet on the other hand renewable energy sources, particularly wind and solar, seem to offer the potential for local zero-emissions energy production to meet local demand, satisfying the requirements of isolated populations in less developed jurisdictions and providing vitally-needed development opportunities (while also avoiding the perennially-tricky issue of nuclear waste management). In reality a combination approach is probably required. It would be foolish to disavow the golden opportunity presented by nuclear power, and just as nonsensical to arrest further development of new, innovative renewable energy sources, which can provide power where nuclear cannot yet reach.

Trump's energy plans: a brief update

Back in November, just after the U.S. presidential election delivered its surprise result, this page examined the likely consequences of Donald Trump’s plans for energy and climate change in the United States and around the world. With Mr. Trump's inauguration just over a fortnight away, this post will briefly examine what has happened since then in this regard.

A Trump campaign infographic with some colourful claims about Democrats' energy 'restrictions' (Source: Trump campaign)

One conclusion of the post was that most or all action on GHG emissions and climate change at the federal level could be expected to be cancelled or reversed. This prediction appears to have been borne out, not least by Mr. Trump’s cabinet appointments. His choice of Energy Secretary, former Texas Governor Rick Perry, is a firm advocate of continued oil drilling and has expressed sceptical views regarding anthropogenic climate change. The incoming head of the Environmental Protection Agency, Oklahoma Attorney General Scott Pruitt, is an even stronger climate sceptic, and is currently involved in a lawsuit against his new department which aims to scupper the Obama administration’s Clean Power Plan. One possible exception to the rule is Trump’s choice for Secretary of State – ExxonMobil chairman and CEO Rex Tillerson has repeatedly asserted that climate change is real and man-made, and endorsed action to combat it.

The original post also forecast that a lack of U.S. financial contributions could derail the Paris Agreement, reached at the 21^st Conference of Parties at Paris in 2015. This may ultimately depend upon the extent to which the new administration is able to extricate the U.S. from the commitments which its predecessor made at COP21, which it is of course too early to know. Assuming an absence of ongoing U.S. support, the success of the Paris and future agreements will depend on the remaining signatory countries. Within a day of Trump’s victory, countries restated their commitment to the Paris Agreement and to COP22, which was underway that same month in Marrakech. At the same conference, the then-Secretary General of the UN, Ban Ki-Moon, expressed his view that global climate action had become ‘unstoppable’ despite Mr. Trump’s pledges to the contrary.

A final prediction made in the post back in November was that, with the disappearance of federal direction, including the Clean Power Plan, states may take up the slack and introduce new action to reduce GHG emissions. In California, ambitious legislative targets mean that the state is on track to return to 1990 levels of GHG emissions by 2020, with a further 40% reduction by 2030. In the north-eastern U.S., several states have devised the Regional Greenhouse Gas Initiative, a unified cap-and-trade programme aiming to reduce emissions. However, other states continue to have no emissions-reduction strategy and have indeed been campaigning for the Supreme Court to throw out the CPP. With the election of Mr. Trump, they can likely abandon any and all efforts to reduce GHG emissions or invest in alternative energy sources, which may lead to significant increases in GHG emissions.

Sustainable transport

One of the greatest challenges to be addressed in reducing global emissions of GHGs, while maintaining (and increasing) energy supplies, is that of implementing sustainable transport solutions. The issue of GHG emissions from the transport sector was briefly addressed by this page in November (‘Costa Rica: clean power superstar?’), where it was noted that emissions from the transport sector account for 70% of that country’s total GHG emissions. Globally, as of 2010, the transport sector consumed 2,200 Mtoe, or around 19% of total global energy supply (WEC, 2011). In terms of GHG emissions, as of 2013 the transport sector was responsible for emitting 7.5 billion tonnes of CO2 in 2013, representing 23.4% of total global CO2 emissions (up from 22.7% in 2010) (IEA, 2015a). It is therefore imperative that new low or zero-emissions means of powering the global transport sector are found, which allow GHG emissions to be dramatically reduced without compromising the ability of global transport systems to efficiently and reliably conduct ever-increasing volumes of passenger traffic and freight. The transport sector consists of four main components: rail, shipping, road and aviation. All are currently overwhelmingly dependent on traditional fossil-fuel propulsion methods. This post will examine each in turn, and assess the various means of low-or-zero-emissions propulsion by which each could most practicably be made more sustainable.

Rail

According to the International Energy Agency (2015a), as of 2013, rail transport accounted for just 2% of total energy used in the transport sector and only 3.5% of CO2 emissions from transport, yet provides 6.4% of global passenger transport and 8.7% of freight transport. It is widely accepted that the most effective means of reducing GHG emissions (and increasing energy efficiency) in rail transport is electrification, which is already a well-established means of rail propulsion, fuelling 36.4% of global rail transport (compared to 57% fuelled by oil products). Electric trains emit 20-35% less CO2 per passenger mile than their diesel counterparts (DfT, 2009). This advantage will be enhanced as more electricity is generated from renewable sources – already 8.7% of total global rail transport is powered by renewable means (IEA, 2015a). Electrification of rail systems coupled with increasing zero-emissions generating capacity has the potential to practically eliminate CO2 emissions from rail transport, already highly efficient in terms of energy consumption per passenger/freight mile, and make rail a formidable component of future sustainable transport systems.

However, rail electrification is a potentially demanding means of reducing GHG emissions from transport. Installation of the necessary infrastructure requires capital expenditure in the order of billions of pounds, which may make large-scale electrification an impossibility in less economically prosperous jurisdictions (Keen and Phillpotts, 2010). One possible solution (employed by the UK’s Network Rail to facilitate its own programme of electrification) is to introduce hybrid rolling stock which can operate on diesel power until electric infrastructure is completed, and subsequently operate as an electric locomotive. This could allow the staggered introduction of electric infrastructure, reducing the financial burden and easing the process.

Shipping

As of 2013, global maritime navigation was responsible for 9.4% of total energy consumption in the transport sector, translating into 10.2% of CO2 emissions from transport (IEA, 2015a). According to a report by the European Commission, by 2050 CO2 emissions from global shipping are forecast to increase by 50-250%. Numerous measures have been proposed which could dramatically reduce emissions from global shipping by up to 75% through operational changes and the application of existing technologies – these measures include streamlining ships through hull coating and cleaning, recovery of waste heat, optimisation of trim and ballast, engine tuning, autopilot upgrades and intelligent routing based on weather conditions. By far the most significant reduction in CO2 emissions could be achieved through simply reducing operational speed. However, this must surely represent an unacceptable compromise, given the crucial economic role of shipping in global freight transport – as of 2013, 82.2% of global freight transport was conducted by sea (IEA, 2015a). Rather than simply mitigating emissions from shipping by compromising speed, what is arguably required is a new means of zero-emissions propulsion. Jeffs (2012) argues that nuclear power could provide an established and highly effective means of powering ships – a great number of nuclear powered vessels (predominantly submarines) are presently in service with the navies of several countries, and nuclear propulsion in civilian or merchant vessels is by no means unprecedented. Nuclear-powered ships are capable of speeds easily equivalent to their diesel counterparts, and moreover can sail for thousands more miles without the need to refuel. Converting existing ships to nuclear power, and installing the necessary refuelling infrastructure in ports around the world, would of course represent a Herculean overhaul requiring billions of pounds of investment. Yet nuclear propulsion could represent the only means by which global shipping may continue to expand and conduct growing volumes of international freight while achieving the dramatic reductions in GHG emissions which are urgently required.

Road

In terms of both energy consumption (74.9%) and CO2 emissions (73.5%) from global transport, road transport is by a large majority the most significant contributor (IEA, 2015a). The vast majority of global road transport is conducted by light-duty vehicle (LDV) transport, which includes private cars, and is responsible for 52% of total energy consumption from the entire transport sector (IEA, 2016a). Furthermore, ownership of private cars is growing, especially in the industrialising/recently-industrialised world, where growing incomes are allowing increasing numbers of people to liberate themselves from dependence upon public transport and purchase their own vehicles (Vasconcellos, 1997a; 1997b). By 2050, private car ownership in developing countries is expected to increase by 430-557% compared to 2010 – a modest increase of 36-41% is also forecast in developed countries (WEC, 2010).

It is therefore imperative that the near-total dependence of road vehicle transport on oil-based fuels is dramatically reduced through the large-scale employment of new emissions-free propulsion methods. The most widely-established alternative to traditional internal combustion engine (ICE) power is electric power. As of 2015 there are over 1.26 million electric vehicles (EVs) in use, with global EV numbers having grown at an astonishing rate since 2005, when just hundreds of EVs existed, and even since 2014, in which time the global EV stock has roughly doubled (IEA, 2016b). Strong international policy support coupled with technological advances have made EVs less expensive and more practical in terms of performance and range, although costs remain high and EVs can still only travel a limited distance before having to charge for long periods. One solution to this is the development of EVs in which exhausted batteries can be swapped instantaneously for fully-charged replacements at designated charging points along the highway, in exactly the same way as ICE cars must stop and refuel at petrol stations (Gabay et al. 2011). A further zero-emissions option which could complement electric vehicles are hydrogen fuel cell electric vehicles (FCEVs), which use chemical energy stored within hydrogen fuel to power electric motors to provide propulsion. FCEV technology is far from well-established and there are very few FCEVs in service at present. The technology is also currently highly expensive. Nevertheless, an advantage of FCEVs over traditional electric vehicles is their increased range and ability to refuel quickly, without requiring several hours of stationary charging. In terms of performance FCEVs are essentially equivalent to ICE vehicles. Hydrogen fuel, meanwhile, is abundant and easily accessible, and can indeed be distilled from water, with reserves forecast to suffice for practically indefinite FCEV operation (IEA, 2015b).

While EVs (potentially complemented by FCEVs) may represent the long-term solution to global road transport emissions, a more immediate fix may be available in the form of biofuel. It is estimated that by 2050, biofuels could account for 27% of total global transport fuel, contributing to a significant reduction in CO2 emissions (IEA, 2011). Biofuel may represent a more practical short-to-medium-term means of reducing emissions from road transport than EV technology – commercial deployment could be achieved with relatively little overhaul of existing infrastructure. Existing diesel engines can even in some cases be cheaply converted to run on bio-diesel.

Aviation

Globally, air transport is responsible for 10.3% of energy consumption and produces 10.6% of CO2 emissions from the transport sector. As of 2013, 11.4% of global passenger traffic was conducted by air, along with just 0.8% of global freight (IEA, 2015a). In the UK alone, air traffic is predicted to increase by around 150% by 2050 (Sustainable Aviation, 2016). In terms of propulsion, global aviation is entirely dependent on traditional oil-based fuel, and barring a major technological breakthrough is almost certain to remain so for the foreseeable future. Reductions in CO2 emissions from aviation are consequently focused on improving the fuel-efficiency of aircraft. It is estimated that by 2050, aviation fuel-efficiency could be improved by around 39% from 2010 levels. Modifications in aircraft design will improve aerodynamic performance, reducing fuel consumption, while the use of sustainable fuels (such as biofuel) may contribute to GHG emissions reductions. New highly-efficient engine designs will allow performance to be maintained while reducing fuel consumption. Intelligent management of operational procedures may also improve fuel efficiency. Further ahead, it is even possible that hydrogen fuel cell technology may allow the operation of zero-emissions commercial aircraft, although such developments are in the very early stages of testing (Sustainable Aviation, 2016).

Conclusions

This has been an extremely overlong post so conclusions will be brief. In short, given the significant contribution of global transport systems to total energy consumption, profound  changes to traditional propulsion methods must take place over the course of the 21^st century in order to significantly reduce GHG emissions from transport. Solutions range from the radical and extremely complex (i.e. nuclear shipping) to the established and easily practicable (i.e. rail electrification). The most practicable solutions should be implemented as a matter of urgency, yet all other options must be seriously considered and innovative solutions applied in order to satisfy ever-increasing passenger and freight demand while achieving material reductions in GHG emissions over the course of the coming decades.

The Impossible Dream

In 1920, The Observatory journal published an article by Arthur Eddington entitled ‘The internal constitution of the stars’. In his paper, Eddington proposed, for the first time, that stars derive their immense energy from the internal fusion of atomic nuclei (Eddington, 1920). Only under the enormous gravitational pressure within the star’s core can the nuclei come close enough for the strong nuclear force attracting them together overcome the much wider-ranging electrostatic force pushing them apart, allowing them to fuse into a single larger nucleus in an exothermic reaction, releasing the energy which the star radiates (nuclear fusion can be understood as the opposite of nuclear fission, in which energy is released by splitting one large atomic nucleus into two smaller daughter nuclei). Understanding of the process by which this occurs was further developed throughout the 1920s and 1930s by Atkinson and Houtermans (1929) and by Bethe (1939).

It was of course soon realised that if a controlled and sustained fusion reaction could be replicated on Earth, it could provide a nearly-limitless source of low-cost power. Throughout the 1940s and 1950s experimental fusion devices were tested in Britain, France, Germany, the United States and the Soviet Union. In 1968, Soviet scientists developed the tokamak device, which magnetically confines the particles used as fuel in the fusion reaction, and remains the principal type of device used to achieve fusion power in modern experiments (Highfield et al. 2009).

Achieving electricity production by nuclear fusion on a commercial scale could, in short, provide a practically limitless source of low-cost and zero-emissions electricity sufficient to replace all present forms of fossil-fuel, nuclear fission, renewable and other sources of power (Kirk, 2016). Of the two hydrogen isotopes which constitute the only fuel required for fusion reactions (deuterium and tritium), deuterium is easily (and routinely) distilled from any kind of water, while tritium is produced from lithium, of which proven terrestrial reserves are estimated to be sufficient for over 1,000 years of fusion power – furthermore, lithium can be extracted from ocean water, where it is estimated that reserves would be sufficient to meet global fusion energy requirements for six million years (ITER, 2016). The sole emission of deuterium-tritium nuclear fusion is helium, meaning that fusion power could eliminate emissions of CO2 and other GHGs, of any other pollutants associated with fossil-fuel power, and of radioactive waste produced by nuclear fission which remains hazardous for tens of thousands of years (Kirk, 2016). In addition, environmental damage associated with fossil and nuclear fuel extraction would be eliminated due to the straightforward and environmentally benign process of extracting deuterium and tritium from ocean water.

If the eternal supply of bountiful, clean power from ocean water seems too good to be true, it might be. Although research into nuclear fusion has yielded impressive and encouraging results, commercial-scale application remains a very long way away. The record for the longest sustained plasma duration is held by the French Tore Supra tokamak at 6 minutes and 30 seconds (ITER, 2016), while the current record for power output is held by the Joint European Torus (JET) in the UK, at 16.1 MW representing ~70% of input power (Cowley, 2010) – in short, a fusion reaction presently requires more energy to initiate and sustain that it can produce. In the near future, the ITER project (an international collaboration between the European Union, the United States, China, India, Japan, Korea and Russia) aims to produce 500 MW of power from an input of 50 MW, and dramatically increase the duration over which the plasma can be contained and the fusion reaction sustained (ITER, 2016). The most significant challenge in achieving sustained fusion reactions which produce meaningful amounts of power is the magnetic confinement of hydrogen plasma at hundreds of millions of degrees Kelvin – the very short duration of current fusion experiments is in large part due to the difficulty of magnetically containing the plasma over long periods (Kirk, 2016; MIT, 2016). The ITER project hopes to use an advanced combination of magnetic fields operating in tandem to successfully achieve longer confinement durations (ITER, 2016).

So how much store should we really set by the development of fusion power? The UK government’s Atomic Energy Authority (UKAEA) states that ‘nuclear fusion… could play a big part in our sustainable energy future’, and it is the stated aim of the organisation to keep the UK at the very forefront of fusion research globally, and to design the world’s first nuclear fusion power plant in the UK (UKAEA, 2016). However, despite general optimism regarding the prospect of achieving commercial-scale fusion power production within the next century or two, the need to dramatically reduce global GHG emissions while increasing energy supply is far more urgent than that (as I sought to illustrate in my first post to this blog). Nuclear fusion remains very much a matter of continued scientific research, and more generally UK energy policy is increasingly focused on developing new nuclear fission generating capacity in order to reduce GHG emissions while maintaining energy security using established and proven zero-emissions technology (GOV.UK, 2015).  In the short-to-medium term, it undoubtedly makes sense for policy and research focus to concentrate firmly on established means of low-emissions electricity production, such as renewables or nuclear fission.

However, in the longer-term, it is argued that the very continuation of human progress and growth is dependent upon the successful application of fusion power. Lee and Saw (2011) argue that even if the ambitious goal of commercial fusion power by the end of the 21^st century is achieved, during the second half of the century humanity will be plagued by energy shortage, stifling human progress. They further argue that in the total absence of fusion power, chronic shortfalls in global energy supply will ultimately result in ‘a severe downturn unavoidably in the fortunes of Mankind with world population shrinking below 5 billion and eventually even lower’ (p.398). In summary, the urgency of the need to address GHG emissions and increasing demand for energy means that in the short term, the development and application of established means of low-emissions energy production must be prioritised – however, in the longer-term, fusion power should provide the means for continued human population growth and technological progress into the 22^nd century and well beyond.

The role of public opinion

In previous posts to this page, I have mainly focused on the relative merits of different methods of sustainable energy production from an objective point of view, based on effective delivery of adequate generating capacity and minimisation of environmental impact.

However, in democracies in particular, government policy is often dictated not through rational scientific consideration, but is decided in large part to appease public opinion. Energy policy, often a high-profile and controversial matter, is no different. Public opinion (often propelled, amplified and escalated by the media; see Gamson and Modigliani, 1989) has frequently proved a significant obstacle to the development of sound energy strategies. Indeed, this page has already examined the likely impact of the results of the 2016 United States presidential election on that country's energy policy - arguably a prime example of an objectively reasonable energy programme being rejected by a dissatisfied electorate who would much rather see their fossil-fuel-extraction jobs return. Jeffs (2012), who's book this page reviewed back in November, places the blame for the lack of new global nuclear power development squarely at the feet of 'green anti-nuclear fanatics' (p.122), whom Jeffs accuses of using fear-mongering and misinformation to manipulate public opinion and cement opposition to nuclear power.

In evaluating options for sustainable future energy production, it is therefore obligatory to examine the state of public opinion regarding different means of energy production, and the public's priorities for government energy policy. This reality is, of course, widely understood, and as such a large volume of literature and research on the matter exists. Such analyses very often focus on nuclear power. Studies conducted based on polling conducted during the latter decades of the 20th century, and the beginning of the 21st century, have revealed a stark division in terms of public opinion on the issue of nuclear power in the United States, with many supporters and many opposed; however, the latter three decades of the 20th century saw a definite inversion of public attitudes, from majority support for further development of nuclear power in the mid-1970s to definite majority opposition during the 1990s (Rosa and Dunlap, 1994). Prevailing public opposition to nuclear power has continued into the 2000s and 2010s, although it has become a more closely-fought debate (Funk and Rainie, 2015). In the United Kingdom, support for nuclear power is stronger, with one study showing 46% in favour with 25% opposed (Chambers, 2013), while in France (which generates around 70% of its electricity from nuclear power), public opinion is also relatively favourable at 36% to 14% opposed (WNN, 2013). Globally, however, public support for nuclear power is low and declining (see Figure 1) - this is perhaps reflected in the fact that in Belgium, Germany, Spain and Switzerland, nuclear power is in the process of being permanently phased-out (Fertl, 2011; Kanter, 2011; Simpson and Fairlie, 2016), while at least 15 major countries have no nuclear generating capacity and no plans to install any (The Economist, 2011).

Figure 1. (from Black, 2011)

For other forms of renewable energy, public opinion is much less divided. Funk and Rainie (2015) found that 60% of U.S. respondents believe that developing renewable energy sources should be a priority, compared with 30% who believe that fossil-fuel development should continue. Globally, 71% believe that their country 'could almost entirely replace coal and nuclear energy within 20 years by becoming highly energy-efficient and focusing on generating energy from the Sun and wind', while just 22% believe that new reactors should be built (Black, 2011).

So, what may be the implications of these findings for energy policy? Is it the case that national energy strategies must answer primarily to public opinion, which is not only often irrational but also varies unpredictably over time? Studies and experience present a mixed picture. Governments have been shown to dramatically alter national energy policy in response to public opinion, such as those (above) which have abandoned nuclear energy - in the U.K., meanwhile, then-Prime Minister David Cameron pledged in 2014 to halt the development of on-shore wind farms, claiming that the public were 'fed up' with them (BBC, 2014). However, this picture is not as clear as it appears - a 2016 study actually found that 71% of U.K. respondents supported on-shore wind farms (RenewableUK, 2016). This may, therefore, be a case of a government wishing to appear to respond to public opinion (or at least being selective in referring to popular attitudes), while in fact developing an energy strategy grounded in more rational motivations. It has been further suggested that there is a simple explanation for the apparently frequent relationship between public opinion and government energy policy; far from public opinion dictating energy policy, it is suggested that energy policy dictates public opinion (Boehmer-Christiansen, 1990). Finally, Kovaks and Eng (2010) found that while people do take an interest in how the electricity they consume is generated, their primary concern (and therefore priority in terms of energy strategy) is the domestic cost of energy.

This impression of the role of public opinion in energy policy should be instructive. Governments must of course respect the voice of the public on any matter, not just from an ethical perspective, but for the simple, practical reason that they rely on democratic support to remain in power. However, governments should also not underestimate their ability to a) act against the tide of public opinion, hich may ultimately result in increasing sympathy for their approach, and b) encourage the dissemination of information of information about the costs and benefits of different sources of energy (from sources which the public trust - see Kovaks and Eng, 2010), based on public priorities, to manipulate public opinion and inspire more supportive attitudes.

Costa Rica: 'clean power superstar'?

In the past year or so, a number of media reports have appeared which usually look something like this:

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Indeed, there appears to be somewhat of a media consensus that this small Central American country is (as described in the EcoWatch article) a 'clean power superstar'. There is indeed justification for this praise. Costa Rica does undoubtedly generate the vast majority of its electricity from renewable sources (Nandwani, 2006). Moreover, the country's per capita emissions of carbon dioxide are just 1.6 metric tonnes, well below those of other Latin American countries at comparable levels of development (UNDP, 2015) such as Mexico (3.9 tonnes) and Cuba (3.5 tonnes) (World Bank, 2016). Accordingly, Costa Rica is one of only five countries credited by the Climate Action Tracker as taking 'sufficient' measures to fulfil its contribution to keeping global temperature increase below 2 degrees C. This classification is supported by the Costa Rican government's undoubted will to take action regarding GHG emissions, having published a National Climate Change Strategy in 2008 which aims for carbon neutrality by 2021 (though Costa Rica's more recent Intended Nationally Determined Contribution, submitted to the United Nations Framework Convention on Climate Change [UNFCCC] in 2015, was far less ambitious, postponing the goal of carbon neutrality until 2085).

It would initially appear, therefore, that Costa Rica is indeed a 'superstar' in terms of renewable energy production and limiting GHG emissions. This provokes the idea that Costa Rica's approach to energy production could potentially represent an example for other countries to follow to meet their own emissions reduction targets. However, we should be cautious before prescribing global solutions based on what appears successful in one instance alone. When it comes to producing electricity from renewable sources, Costa Rica has some significant geographical advantages. Due to its tropical latitude, the country has extremely high summer rainfall, allowing large-scale hydro-power production. Volcanoes are also relatively abundant within Costa Rica's territory, making large-scale geothermal power possible (Nandwani, 2006). A further caveat is that Costa Rica simply requires less energy than many other countries, with a small population (under 5 million) and no large-scale industry to power (Fendt, 2016). Moreover, despite very low GHG emissions from electricity production, growing ownership of private cars constitutes a significant challenge for Costa Rica in terms of achieving carbon neutrality - emissions from the transport sector already account for nearly 70% of the country's total GHG emissions (Pratt, 2010). For all the country's successes with regard to the renewable production of electricity, huge changes must be made within Costa Rica's transport sector if emissions targets are to be met. Costa Rica must demonstrate how an effective, low-emissions transport network can be developed before it can truly be called a 'clean power superstar'.

It is doubtful that many other countries can use the example set by Costa Rica to guide them in reducing their own GHG emissions. Most other countries do not have the geographical advantages enjoyed by Costa Rica, and often require far higher generating capacity to sustain larger populations and more developed industry. Yet the country's overall attitude towards an active focus on renewable energy, and seriously ambitious emissions targets, should provide an example to other countries. With a focus on appropriate methods of low-carbon energy production, even countries with very high energy use can achieve impressive results. In the 3rd quarter of 2016, the UK generated over 50% of its electricity from low-emissions sources, of which nearly half (46%) was generated from nuclear power or renewables, which produce zero GHG emissions (Watts, 2016). France, meanwhile, currently generates around 78% of its electricity from emissions-free nuclear power. In summary, it is beyond doubt that the means exist for any country to effect dramatic reductions in GHG emissions while maintaining sufficient generating capacity. However, significant challenges remain in other sectors of energy production, not least that of transport.

US elections - what does President Trump mean for energy in the United States?

"Some country is going to be the clean energy superpower of the 21st century". That was the prediction of Democratic presidential nominee Hillary Clinton, in her first debate standoff with Republican Donald Trump back in September.

Fast-forward to the results of the 2016 election, and it looks unlikely that that country will be the United States. President-elect Trump has repeatedly dismissed anthropogenic climate change as an 'expensive hoax', 'nonsense' and 'bulls**t', and has made explicitly clear that he plans to reverse the Obama administration's commitments to investing in renewable energy and reducing GHG emissions, which Trump regards as a pointless and destructive influence on the American economy and jobs. So just how dramatic an impact is Trump's imminent presidency likely to have on energy production and climate change policy in the United States?

First, some context. The total energy consumption of the United States in 2015 was 1763.8 million tonnes of oil equivalent (Mtoe), representing a remarkable 30.87% of total global energy consumption (5712.89 Mtoe) (BP, 2016). Of this total consumption, 33% was generated by coal power, 33% by natural gas, 20% by nuclear power, 6% by hydroelectric power, 7% by other renewable energy sources and 1% by petroleum (USEIA, 2016). In 2013 (the most recent year for which data is available), the United States was responsible for CO2 emissions totalling 1414.28 million metric tonnes of carbon (MtC), representing 14.47% of total global emissions (~9776 MtC) (CDIAC, 2013). The huge proportion of total global energy consumption, and of CO2 emissions, for which the United States is responsible, means that changes in energy policy in the United States are likely to have profound global impacts.

Under present plans, the United States Environmental Protection Agency (EPA) estimates that its Clean Power Plan (CPP), which requires states to reduce CO2 emissions from electricity production, will result in a 32% reduction from 2005 levels in CO2 emissions by 2030. (Jones and Martin, 2016). Mr. Trump, however, has firmly indicated that he will seek to abandon President Obama's Climate Action Plan, of which the Clean Air Act (which contains the CPP) is a key component. Without the CPP, the EPA estimates that by 2030, US CO2 emissions from the power sector will total around 1,900 million metric tonnes of CO2 (MtCO2) (Jones and Martin, 2016) (note that in contrast to the CDIAC figures which are given in million metric tonnes of carbon, projections from the EPA are given in million metric tonnes of carbon dioxide, resulting in a higher figure). The 2030 emissions estimate without CPP represents only a 20.83% reduction from 2005 levels in CO2 emissions - President-elect Trump's aim of scrapping the CPP would therefore result in the United States producing significantly higher CO2 emissions during the next decades.

However, the impending about-face in federal climate policy under Mr. Trump will not mean a total abandonment of the pursuit of emissions reductions in the United States. Energy policy in the US is largely dictated at the level of individual states - as of 2016, 34 states (along with the District of Columbia) have enacted climate action plans, with 20 states (and D.C.) introducing GHG emissions reduction targets and 29 states, D.C. and two US territories implementing Renewable Portfolio Standards (RPS), which specify that a certain proportion of energy must be generated through renewable means by a given date (CSS, 2016).

It is possible, therefore, that the domestic impact on climate policy of a Trump administration will be limited. However, the international impact may be more significant. Mr. Trump has explicitly pledged to revoke the United States' commitment to the 2015 Paris Climate Conference (21st Conference of Parties; COP21). The Paris agreement mandates not only that parties take measures to reduce domestic GHG emissions (i.e. the CPP), but also that:

'Developed country Parties shall provide financial resources to assist Developing country Parties with respect to both mitigation and adaptation... developed country Parties should continue to take the lead in mobilising climate finance'.

- from Article 9 of the Paris Agreement, 2015

This commitment from wealthier countries to provide financial support to less developed countries in developing emissions mitigation strategies was instrumental in persuading poorer countries to sign up to the agreement, including huge emitters such as India (Le Page, 2016). Without US financial support, it is possible that some less developed countries will renege on their recent climate commitments, and likely that many will be unwilling to implement the intensified future mitigation strategies required if global warming is to be limited to below 1.5 degrees C (the target agreed at COP21).

In summary, during Trump's presidency, any action on climate change and GHG emissions at the federal level can be expected to be cancelled or reversed, including international agreements - due to the high contribution of the US to global emissions, and the importance of the US in terms of funding GHG mitigation measured internationally, this is likely to have a significant impact on global emissions over the coming years. However, domestically at least, Mr. Trump's power to enact changes is relatively limited and so impacts may be less severe - but a lack of federal legislation and impetus towards emissions reductions may cause some states to soften their own approaches towards action on climate change, causing further increases in future GHG emissions.

References:
BP (2016), Energy Charting Tool (http://tools.bp.com/energy-charting-tool.aspx#/st/primary_energy/dt/consumption/unit/MTOE/country/CA/MX/US/view/map/; 09/11/2016)
Carbon Dioxide Information Analysis Centre (CDIAC) (2013), Global fossil fuel CO2 emissions (http://cdiac.ornl.gov/trends/emis/top2013.tot; 09/11/2016)
Center for Sustainable Systems (CSS), University of Michigan (2016), Climate Change: Policy and Mitigation Factsheet, Ann Arbor: CSS (link: http://css.snre.umich.edu/sites/default/files/Climate_Change_Policy_and_Mitigation_Factsheet_CSS05-20.pdf)
21st Conference of the Parties (COP21) (2015), Paris Agreement (http://unfccc.int/files/meetings/paris_nov_2015/application/pdf/paris_agreement_english_.pdf; 09/11/2016)
Jones and Martin (2016), Effects of the Clean Power Plan, Washington D.C.: United States Energy Information Administration (USEIA) (link: http://www.eia.gov/forecasts/aeo/section_issues.cfm#cpp)
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