低碳经济发展模式文献综述及外文文献资料

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标题: A practitioner's guide to a low-carbon economy: lessons from the UK

作者: Fankhauser, Samuel. 期刊: Climate Policy

卷: 13；期: 3；页: 345-362；年份: 2013

A practitioner's guide to a low-carbon economy: lessons from the UK Abstract

Practically all major GHG emitters now have climate change legislation on their statute books. Given what is at stake, and the complexity of the task at hand, it is important that policy makers learn from each other and establish a code of good low-carbon practice. The main lessons from the UK are distilled and presented. Carbon policy is considered for key sectors, such as electricity, buildings, and transport, and possible decarburization paths are also outlined. It is shown that the transition to a low-carbon economy is economically and technologically feasible. Achieving it is primarily a question of policy competence and political will. This in turn means that climate change action needs a strong legislative basis to give the reforms statutory legitimacy. Low-carbon policies will have to address a wide range of market, investment and behavioral failures. Putting a price on carbon is an essential starting point, but only one of many policy reforms.

Keywords: climate change policy; decarburization; green growth; low-carbon transition;

1. Introduction

More and more countries are taking action against climate

change. Nearly all major GHG emitters, including many emerging markets, now have climate change legislation on their statute books (Town- shend et ak, 2011). It is debatable whether these efforts - and any international agreement that might reinforce them - will be sufficient to limit climate change to an acceptable level. However, given what is at stake, and the complexity of the task at hand, it is important that policy makers learn from one another and establish a code of good low-carbon practice. This article attempts to distil the main lessons from the UK.

The climate change debate in the UK is fairly advanced, with a strong legal basis for climate action, ambitious targets, and sophisticated institutional arrangements (Fankhauser, Kennedy, & Skea, 2009). The UK also has a constantly evolving regulatory landscape, with occasional policy failures and U- turns, while a waning commitment among politicians and latent climate scepticism in parts of the press are putting the institutional framework increasingly to the test. As such, the UK is a good case from which to learn lessons.1

There is a rich analytical literature on many aspects of climate change policy. For example, much has been written about the relative merit of different policy options (Hepburn, 2006; Pizer, 2002), the design of emissions trading schemes (Fankhauser & Hepburn, 2010a, 2010b; Grüll & Taschini, 2011; Murray, Newell, & Pizer, 2009),

policy performance (Ellerman & Buchner, 2008; Ellerman, Convery, de Perthuis, & Alberola, 2010; Martin, Preux, & Wagner, 2009), and low-carbon innovation (Acemoglu, Aghion, Bursztyn, & Heinous, 2009; Aghion, Boulanger, & Cohen, 2011; Aghion, Dechezleprêtre, Heinous, Martin, & van Reenen, 2011; Dechezleprêtre, Glachant, Hascic, Johnstone, & Ménière, 2011;

Popp, 2002).

This article differs from the existing literature in that it takes an explicitly practical approach. While drawing on the analytical literature, it looks at the specific case of a country that wants to reduce its GHG emissions, in this case the UK. The policy ambition is much deeper than a marginal change in emissions, which is the concern of much of the literature. It is a comprehensive redesign of the modern economy. At the same time, the scope is narrower than that of the green growth literature, which includes wider notions of sustainable development besides low-carbon growth (Bowen & Fan- khauser, 2011). All decarburization efforts will face at least four challenges. First, a strong legal and institutional basis for low-carbon policy must be put in place (Section 2). Second, low-carbon objectives must be translated into a credible roadmap of sector, technology, and reform targets that can guide policy and determine whether the objectives are achievable (Section 3). Third, the necessary policies to implement the roadmap must be put in place (Section 4). Fourth, the wider socio-economic conse- quences of decarburization must be managed (Section 5). It is concluded in Section 6 that the low- carbon transition is achievable if these challenges are met and there is sufficient policy competence and political will.

2. Providing the legal and institutional basis

The starting point for economy-wide decarburization is a strong legislative basis. The fundamental reforms to energy, transport, industrial, agricultural, and fiscal policy that will follow will need statu- tory legitimacy. The adoption of a climate change law is also a way of forging the broad political con- sensus needed during implementation. It is striking how many of the climate change laws in major economies have been bipartisan

efforts (Townshend et ak, 2011). The UK Climate Change Act of 2008, for example, was passed near-unanimously.

Most climate change laws are unifying laws that bring together existing strands of regulation (e.g. on energy efficiency), express a long-term objective, and create a platform for subsequent action. The UK Climate Change Act calls for a cut in GHG emissions of at least 80%, relative to 1990, by 2050. This is based on an ambition to limit median global warming to 2°C and keep the risk of extreme climate change (of say 4°C) to a minimum. The Act also defines the mechanism through which the long- term target is to be met: a series of statutory, 5-year carbon budgets that set a binding ceiling for GHG emissions over that period. The UK has been subject to this economy-wide carbon constraint since 2008.

One of the key purposes of the legislation is to make a statement of intent that can subsequently guide policy delivery and reduce uncertainty for decision makers. Although action is required immedi- ately, building a low-carbon economy will take decades, a much longer term than policy makers can credibly commit. This creates problems for businesses, which will mistrust the long-term validity of the plan and hedge their behaviour. An important role of climate change legislation is to overcome

such time inconsistency problems and instil long-term credibility into the policy effort.

The issue is akin to the credibility of inflation targets (Kydland & Prescott, 1977; Barro & Gordon, 1983; Rogoff, 1985), and the institutional remedies that have been proposed for both problems bear some resemblance to one another. An independent institution, the Committee on Climate Change (CCC), was created to recommend and monitor carbon budgets,

in the belief that technocrats are more likely to take a long-term view than politicians. However, the carbon budgets are ultimately passed by Parlia- ment to give them statutory credibility. A judicial review is likely if the government systematically ignores the Committee's advice or if key policy decisions are inconsistent with carbon objectives.

3. Defining a strategy for delivery

For the high-level objectives of the climate law to be credible they need to be backed up by a sound implementation strategy. The UK, EU, and many other jurisdictions have developed concrete decarbo- nization roadmaps for this purpose (CCC, 2010; DECC, 2011; EC, 2011). These are not blueprints that need to be implemented to the letter. The markets and private initiative will determine most of the details. However, they represent important strategies that will detennine the speed and direction of travel.

These roadmaps are underpinned by a fair amount of technical analysis, which ensures that the strat- egy is technologically and economically rational, as well as consistent with the ultimate emissions objective. Numerical simulation models are well suited to the calculation of the least-cost way of meeting a certain emissions target under given technology constraints. In the UK, both the CCC and the Department of Energy and Climate Change (DECC) have used such models to inform their low-carbon roadmaps. The model evidence used by the CCC, in particular, is quite detailed. Even so, model results are heavily complemented and qualified by professional judgement.

Least-cost optimization models (e.g. MARKAL) are used to determine the correct choice of technol- ogies as a function of their cost profiles (CCC, 2010), which are themselves derived from

detailed engin- eering studies (e.g. Mott McDonald, 2011). Least-cost models also inform the allocation of scarce resources among competing uses; e.g. in determining whether the limited supply of sustainable biomass should be used for electricity generation, heating, or transport (CCC, 2011a). Detailed models of the electricity market can simulate how the power sector will cope with a rising share of inter- mittent renewables and inflexible nuclear capacity (P?yry, 2011). Least-cost models provide estimates of the likely economic costs, although these bottom-up estimates should be complemented with general equilibrium or macro-econometric model mns (Barker et ak, 2007).

A key question that the roadmap should answer is about the speed of decarbonization: 'What is the most economically rational rate of bringing emissions down?' The anticipated fall in the cost of low- carbon technologies and the effect of discounting suggests that a slow start will be followed by steep emissions reductions later.2 However, progress in reducing technology costs is a function of cumulative

investment, not just the passage of time. Postponing low-carbon investment may therefore delay the point at which these technologies become cost-effective. Scientists can also point to the climate benefits of acting early: future climate change is determined by the sum total of emissions over time, and not their level in an arbitrary future year (Meinshausen et ak, 2009), so each year of delay imposes a social and environmental climate cost.

Moreover, there are limits to the speed at which emissions may be reduced cost-effectively later. As an illustration, if carbon-intensive capital has a lifetime of 25 years, the maximum annual emissions cut that can be achieved through the regular

investment cycle is 4%. To achieve this, all new invest- ment (in both replacement and expansionary capital) would have to be carbon-free. Going beyond 4% would require the premature scrapping of existing capital. This is expensive unless productivity improvements (e.g. through energy efficiency) are so high that an overall reduction in the capital stock is warranted. It is argued below that this is not the case.

The UK debate about the speed of reducing emissions has been heavily influenced by the particular time profile of investment needed in UK power sector. A large proportion of UK power plants are due for renewal in the 2020s. This creates both an opportunity and a need to decarbonize power generation early, as the investments made in the 2020s will determine electricity emissions for many decades to come. For these reasons, the CCC has recommended a swift pace of emission reductions in the power sector and an overall abatement path that is only slightly back-loaded (see Figure 1). This decarbonization path has profound implications not just for electricity generation, but for all emitting sectors.

3.1. Energy

The decarbonization of the electricity sector is at the core of the low-carbon transition in UK and all industrialized countries, for several reasons. First, power generation is a major source of GHG emissions (see Figure 1). Second, low-carbon power generation is well-understood and feasible. A number of low- carbon options are available, including renewable energy (wind, solar, biomass, hydro, and in time perhaps even marine), nuclear energy, and the as yet unproven carbon capture and storage (CCS). Although each of these options has its challenges - related to cost (off-shore wind, perhaps nuclear), public acceptability

(nuclear, onshore wind), and/or commercial availability (CCS, marine) - they provide an adequate technological basis and choice in low-carbon power generation. Third, decarbo- nized electricity has an important role to play in reducing emissions in other sectors, chief among them transport (through battery electric vehicles), residential heating (through ground source and air source heat pumps), and perhaps some parts of industry.

Any combination of renewables, nuclear, and CCS will succeed in bringing down the carbon inten- sity of power production. The choice is determined by cost, environmental considerations, and issues of system operation, and different countries make this choice differently. Germany, for example, has resisted nuclear energy, but invested heavily in solar energy. The UK has emphasized wind power over solar photovoltaics, and so far has accepted nuclear power. It is putting particular emphasis on off- shore wind, which is more expensive than onshore wind but raises fewer local

environmental concerns (Bassi, Bowen, & Bankh?user, 2012). The carbon intensity of electricity is required to fall by as much as 90% within 20 years, from over 500 gC02/kWh to 50 gC02/kWh, according to the timetable of the CCC (CCC, 2010). This tight target reduces the scope of intermediate technologies like gas, which might otherwise be attractive. Modern combined cycle gas turbines emit around 350 gC02/kWh, which is a considerable improvement on the current system average but too much in a truly low-carbon power sector. Unless fitted with CCS, future gas-fired power plants will therefore only be used spar- ingly, primarily as back-up capacity. This is a limited but important role. The combination of inter- mittent wind and baseload nuclear power creates challenges for load management,

as neither is particularly flexible in responding to short-term fluctuations in demand. Gas can provide that flexibility and balance supply and demand. However, electricity market arrangements in the UK do not currently reward a mode of operation in which a plant is predominantly idle. This will have to change.

Current electricity market arrangements create another obstacle to low-carbon investment. Power prices are presently determined competitively to reflect short-term operating costs. Low-carbon tech- nologies, such as nuclear and wind, typically have high capital costs and low operating costs. If they come to dominate the sector and set short-term marginal costs, market prices may fall to a level that is too low to recoup the upfront costs. In this case, further investment would stall.

Reform of the electricity market has therefore become an essential prerequisite for decarbonization. After decades of liberalization, the reforms will bring about an increased role for the state. State inter- vention will be aimed, in particular, at rectifying three market failures that would otherwise prevent low-carbon investment. First, the state can put a price on carbon to internalize the climate change externality. Ideally, this would happen through a carbon tax or a stringent emissions trading scheme. The reality in the UK is somewhat more complicated. The EU Emissions Trading Scheme (EU ETS) provides only a relatively weak price signal. The UK has thus legislated a unilateral carbon price floor to strengthen this signal. While this will motivate UK emitters to abate further, it will not reduce EU-wide emissions, which con- tinue to be set by the unchanged ETS cap (Fankhauser & Hepburn, 2010a, 2010b). The price instru- ments are complemented by a regulatory measure, an emissions

performance standard set at (a high) 450 gC02/kWh.

Second, the state can promote low-carbon (in particular renewable) energy and address market fail- ures related to technology development by using the classic instruments of either renewable energy obligations or feed-in tariffs (Section 4). The UK is moving from the former system to a variation of the latter, with the introduction of contracts for differences in low-carbon energy. Smaller-scale instal- lations benefit from a straight feed-in tariff. These demand-pull measures are complemented by a mod- erate supply-push from a new green investment bank, which will offer renewable energy investors improved access to finance. An investment subsidy is available for CCS pilots, although this process has been very slow.

Third, the state can focus on the need to ensure investment into back-up capacity, as discussed above. In the UK, this will be achieved through the introduction of capacity

payments. The economic merit and practical challenges of this policy mix are further discussed in Section 4.

3.2. Transport

Surface transport is the second most important source of GHG emissions in the UK after electricity (see Figure 1). Cars dominate transport emissions, although emissions from lorries, vans, and buses are also substantial. Rail accounts for no more than 2% of the transport total.

The strategy to reduce car emissions is two-pronged. In the short term, the emphasis is on reducing the carbon intensity of conventional cars through technological improvements and providing drivers with incentives to switch to more efficient cars. The UK has adopted an EU target to reduce the carbon intensity of new cars from current figure of around 145 g/km to 95 g/km

in 2020. There is a similar target for vans.

In the medium term, further efficiency improvements will have to come from new technologies (e.g. battery electric cars, plug-in electric vehicles, and perhaps fuel-cell-based vehicles). Biofuels will also play a role, with the limited amount of sustainable biofuel probably best targeted at heavy goods vehicles and aviation (where there are fewer alternatives). The CCC has calculated that 60% of new cars sold in 2030 will need to be electric (CCC, 2010), rising to 100% by 2035 for a fully electric car fleet in the late 2040s. These are very ambitious targets, which, if met, will have repercussions on elec- tricity demand and the country's refuelling infrastmcture.

In comparison to technology, the role of demand-side measures will be relatively modest and insuf- ficient to reverse the growth in driving-kilometres, although it will nevertheless be important. Changes in travel behaviour, such as eco-driving, better journey planning, car sharing, and modal shift, can have a significant effect, but alterning entrenched behaviour patterns will require persistent effort (as suggested in a recent UK pilot study on 'smarter choices'; CCC, 2010).

As in the power sector, a diverse set of policies are in place to encourage the transition. Arguably the most powerful - fuel duty - is primarily a fiscal measure; it accounts for almost 5% of total government income and is the most important source of indirect tax revenue after V AT (Adam & Browne, 2011). Fuel duty helps to correct a multitude of transport-related externalities. If the entire levy were treated as a carbon tax, the implicit tax rate would be over ￡200 per tC02 (Bowen & Rydge, 2011).

In addition, other vehicle-related taxes, such as excise duty or company car tax, are differentiated by carbon efficiency.

Electric cars are subsidized by up to ￡5000 per vehicle, while matched funding for recharging stations is provided under the Plug-In Places programme. These policies have been rela- tively effective. Since 2008, the carbon intensity of new cars in the UK has fallen by about 9%, although the uptake of electric cars is still very low.

3.3. Residential buildings and industry

The buildings and industrial sectors, when combined, account for over two-thirds of UK GHG emis- sions. A large part of these are indirect emissions from electricity use, which are assigned to the power sector in carbon accounts. However, both direct and indirect emissions are important from a demand-management perspective.

The initial focus for reducing residential and industry emissions is on energy efficiency. There is much debate about the potential of energy-efficiency measures that are available at low or zero econ- omic cost. In the UK, the CCC expects a 23% reduction in non-electric energy use in buildings and industry by 2020, relative to 2007, and a 13% reduction in electricity use (CCC, 2012).

Over the medium term, the focus may shift from energy efficiency to renewable heat. The CCC expects the share of renewable heat to rise from the current 1% of heat demand to 12% in 2020, much of it back-loaded, as renewable heat is still relatively expensive. From the late 2020s onwards, further decarbonization will require currently expensive options such as solid wall insulation and heat pumps. Additional measures in industry are difficult and will require new emissions reduction techniques. Options include industrial CCS, process innovation, and product substitution, none of which is as yet proven.

Energy-efficiency gains are notoriously elusive. There are a multitude of policy, market, and behav- ioural barriers, some of which are well understood, others less so. This is mirrored in the policy frame- work. No other aspect of UK low-carbon agenda has seen more policy experimentation, and nowhere else is the policy landscape more complex. Although regulatory measures dominate, there are price incentives in the form of a Climate Change Levy (a carbon-cum-energy tax) and the indirect effect of the EU ETS, the cost of both are passed through to end-users. Energy-intensive businesses can avoid the Climate Change Levy by entering into a voluntary Climate Change Agreement; around 50 sectors have already done so.

Renewable heat is subsidized through a renewable heat incentive. The service sector has its own mechanism, the CRC Energy Efficiency scheme, which relies on a combination of reputation effects (through a performance league table) and price incentives (through a carbon tax, later to be converted into a trading scheme). Residential energy efficiency has been promoted primarily through a succes- sion of supplier obligations (which commit energy utilities to certain energy savings or carbon emis- sions targets in their client base) and the much-vaunted Green Deal, which promises easier access to energy-efficiency finance by tying loans to the energy meter rather than householders. Despite this flurry of activity, progress in increasing residential and industrial energy efficiency has been mixed (CCC, 2012).

3.4. Agriculture

Agriculture accounts for perhaps 10% of UK GHG emissions, most in the form of methane (CH4) and nitrous oxide (N20) (CCC, 2012). There are accounting issues, however: agricultural and

land-use emis- sions are known with much less certainty than energy-related emissions. Similarly, low-GHG options for agriculture are less well understood than decarbonization in other sectors.

The available evidence suggests that there is scope to reduce emissions further, e.g. through increased feed efficiency and dietary changes in livestock, the deployment of anaerobic digestion systems, and better nutrient management for crops. However,

beyond

these

low-cost

measures,

deep

decarbonization maybe difficult. On the supply side, further action may engender ethical and environ- mental issues (e.g. related to animal welfare and the role of genetically modified food). On the demand side,

behavioural change with respect to diets is likely to be controversial (although it would have sub- stantial health benefits; see Ganten, Haines, & Souhami, 2010). It is therefore likely that agricultural emissions (together with sectors such as aviation) will account for an increasing fraction of the increas- ingly tighter carbon budgets over the longer term.

Although agriculture is one of the most highly regulated sectors in the UK economy, the policy approach to agricultural decarbonization has chiefly relied on voluntary action. Opportunities to reduce emissions through adjustments in existing policies, such as the EU Nitrates Directive or the Common Agricultural Policy, have not been taken up. Consequently, emissions have primarily been reduced as a result of unrelated policies and developments. Fertilizer-related emissions, for example, have fallen significantly as a consequence of higher prices and regulation. (A similar story holds for waste management, where methane emissions have

fallen sharply as a by-product of an aggressive landfill tax.)

4. Designing policies

As discussed in the previous section, policy measures to create a low-carbon economy are needed on three fronts (Stern, 2006). First, a price should be put on carbon to internalize the climate change externality. Second, low-carbon technology should be promoted by addressing externalities and market failures related to innovation. Third, carbon-efficient behaviour and investment should be encouraged, in particular to unlock the existing energy-efficiency potential.

Although the emphasis is often on the carbon price, all three sets of policies are equally important. As shown in the previous section (see also Bowen & Rydge, 2011), the UK has an elaborate low-carbon policy landscape. There are measures to put a price on carbon (e.g. the EU ETS, Climate Change Levy, carbon price support), to support new technologies (e.g. renewable energy obligations, renewable heat incentives, feed-in tariffs), to provide investor confidence (e.g. electricity market reforms), to change energy-efficiency behaviour (e.g. CRC Energy Efficiency Scheme, supplier obligations), and to facilitate access to finance (e.g. Green Deal, Green Investment Bank). Despite this complexity, which itself poses challenges, independent observers have expressed doubt that the UK policy environment is sufficient to meet the targets the country has set itself (CCC, 2010).

4.1. Putting a price on carbon

There are two generic ways of putting a price on carbon: taxation or an emissions trading scheme.3 There is a large body of literature, going back to Weitzman (1974), on the relative merits of the two options (see Hoel & Karp, 2001; Newell & Pizer, 2003). Most economists probably favour a carbon tax, although

where there are mandatory carbon constraints (as in the UK) the traditional Weitzman argu- ment would advocate quantity-based policies.4

In practice, policy makers have been swayed less by theoretical niceties than by political realities, and in most cases an emissions trading scheme is easier to implement than a carbon tax: it creates a valuable asset - emissions permits - which can be used to pacify industry. In the case of the EU ETS, the stock of permits is worth around euro20 billion a year, and handing them out for free has indeed been

sufficient to secure industry buy-in. However, there has also been a backlash against the windfall profits enjoyed by carbon 'fat cats' (Sandbag, 2011). Indeed, the European Commission has found it hard to reverse the practice of free allocation. This suggests that the use of free permits should be cur- tailed as much as possible from the outset, although some will be necessary to create consensus. The EU ETS has yielded a wealth of other practical lessons, including the need to manage price fluctuations (e.g. through an auction reserve price) and the importance of competent regulation (see Ellerman et ak, 2010; Fankhauser & Hepburn, 2010a, 2010b, for a review).

Even in the presence of an emissions trading scheme, most countries have complementary taxes that cover emissions outside the scheme, strengthen the price signal within it, address other externalities, or simply raise revenue. Levying taxes on top of a trading scheme will have a detrimental effect on the carbon permit price and reduce the gains from trade (Fankhauser & Hepburn, 2010a, 2010b), but there is merit in using the two instruments in parallel in different parts of the economy.

The most effective way of sending a carbon price signal

through taxation is a pure carbon (or carbon- equivalent) tax, probably levied upstream as this would be administratively easier. In practice, policy makers often opt for a combination of carbon and energy taxes, hoping to meet different objectives with one instrument, or responding to industry pressure. The result can be widely different carbon prices across sectors and therefore a potentially inefficient allocation of the abatement burden. Accord- ing to Mirrlees et ak (2011), the implicit carbon tax on UK transport and energy emissions ranges from zero to almost ￡250 per tC02.5 The potential for green taxes and green tax reform is discussed by the Green Fiscal Commission (2009).

4.2. Promoting low-carbon innovation

The central role of new technologies in decarbonization makes innovation policy a critical part of the low-carbon strategy. There are well-known externalities in research and innovation, most of them generic and not related to climate change. Countries have research and development (R&D) policies to address them, such as research grants, innovation prizes, patents, and tax credits, all of which are available to low-carbon innovators.

The question then is whether there are additional market failures involved in low-carbon inno- vation that require further intervention, or whether the combination of a carbon price (to correct the climate externality) and R&D support (to address innovation externalities) would be sufficient. Aghion, Boulanger et ak (2011) have suggested there is a need for further intervention and has found evidence of path dependence - e.g. in the automotive industry (Aghion, Dechezleprêtre, et ak, 2011) - which makes traditional high-carbon research more likely than low-carbon innovation. High-tech firms may also find it harder to

access finance because they create few tangible assets at the outset.

There are a number of market or system failures that prevent new technologies from moving along the innovation chain towards successful commercialization (Foxon et ah, 2005), including a well- documented 'valley of death' between demonstration and pre-commercial deployment (Gmbh, 2004). Policy intervention is therefore required,

including basic research, but also targeted measures to improve the risk/reward ratio for early-stage technologies (Foxon et ak, 2005).

Getting support for demonstration-stage technologies right is not easy, as the UK's experience on CCS shows. The government had committed to supporting up to four CCS demonstration projects but 'took too long to get to grips with the significant technical, commercial, and regulatory risks involved' (NAO 2012). As a consequence, not even the first pilot has yet materialized.

Most countries concentrate their clean-tech support on renewable energy, kipp (2007) has identified 40 jurisdictions (countries or subnational entities) with a feed-in tariff for renewables and a further 38 with tradable renewables certificate systems (sometimes called 'renewable obligations'). Both systems have advantages and disadvantages. Countries with feed-in tariffs, such as Germany, have generally been more successful in building up a renewable energy sector than those with renewable obligations, such as the UK (Butler & Neuhoff, 2007; Menanteau, Finon, & kamy, 2003). However, this may have been achieved at higher costs to consumers. Feed-in tariffs put less emphasis on competition to keep down rents than certificate

systems. Moreover, other factors, such as differences in planning regimes, which are notoriously difficult (Devine-Wright, 2010), may play an equally important role in explaining past performance.

4.3. Overcoming behavioural and managerial barriers Much has been written about the difference between actual and theoretical levels of energy efficiency. The reasons for the gap are well rehearsed and include knowledge gaps, asymmetric information (e.g. between landlords and tenants, shareholders and managers), hidden transaction costs, management issues, bounded rationality, and many others (de Canio, 1998; de Canio & Watkins, 1998; Martin, Mu?ls, de Preux, & Wagner, 2011; Sanstad & Howarth, 1994).

The policy measures to close the energy-efficiency gap are equally diverse, and often pre-date any concern about a low-carbon economy. These include price incentives, regulation (e.g. efficiency stan- dards for buildings and appliances), access to information (e.g. energy performance certificates for buildings), access to services and know-how (e.g. subsidized energy audits), and supplier obligations on energy companies.

Regulation is often the most effective way forward. However, there are examples of market-based instruments, such as trade in energy-savings (or 'white') certificates (Vine & Hamrin, 2008) and the UK CRC Energy Efficiency Scheme. The latter is an (overly) complex piece of regulation aimed at bring- ing energy efficiency to the attention of senior management. An intriguing feature is the use of reputa- tional incentives: participating firms are ranked in a publicly available league table. The idea is not new - the World Bank (1999) highlighted the role of public opinion as an 'informal regulator' over a decade ago - but it remains powerful

today. Particularly consumer-facing businesses are as concerned about their reputation as they are about costs.

The need for lifestyle and behaviour changes is not confined to energy use. Policy intervention may also be required to encourage the uptake of new technologies such

as electric cars or renewable heat. Typically, this has taken the form of financial incentives (e.g. the UK's renewable heat incentive or lower road taxes and subsidies for electric cars). Less well proven are the effects of public information and advertising campaigns, although for more difficult adjustments (e.g. in eating and driving habits), both may be important complements to price signals and increase their political acceptability.

4.4. Policy coordination

The full package of policies to price carbon, promote innovation, and overcome efficiency barriers needs to be assessed as a whole. Policies do not act in isolation but interact with one another, some- times reinforcing and sometimes offsetting each other. In principle, a combination of policies is the best way of tackling multiple market failures (Bennear & Stavins, 2007). However, there are exceptions. In the case of renewables the measures to promote low-carbon investment (e.g. a renewable energy obligation or a feed-in tariff) tend to reduce the price in, and thus the effectiveness of, emissions trading schemes (e.g. Morris, Reilly, & Paltsev, 2010; Unger & Ahlgren, 2005). Forcing renewable energy into the abatement mix alters the marginal emissions reduction activity, which then affects the carbon price. Fankhauser and Hepburn (2010a, 2010b) have found a similar effect in the interaction of carbon taxes and trading schemes. As Bowen and Rydge (2011) have observed, the weakened carbon price signal could have a detrimental effect on

energy efficiency, R&D, and low-carbon investment decisions.

New low-carbon measures also interact with existing policies. For example, two of the most powerful GHG taxes in UK were not introduced with climate change in mind. The fuel duty on petrol was pri- marily a revenue-raising measure, although it also corrects for local externalities (Newbery, 2005), while the landfill tax was primarily intended to modernize waste management, and the powerful impact it has had on UK methane emissions has been coincidental.

The interaction effect is not always positive. The distributional decision to charge a lower rate of V AT on energy means energy consumption in the UK is essentially subsidized compared with other goods (Bowen & Rydge, 2011; Mirrlees et al., 2011).

5. Addressing wider socio-economic effects

Like all change, the transition to a low-carbon economy will create both winners and losers. Policy makers are understandably nervous about any negative socio-economic effects, but are trying to maxi- mize positive spill-overs.

5.1. Competitiveness and jobs

One of the main concerns of policy makers is the effect of decarbonization measures on economic com- petitiveness, particularly if they are more progressive than those of the main trading partners. Indeed, this has become a major source of tension in the UK between business-oriented ministers and those that promote action on climate change. Loss of competitiveness has an environmental corollary in carbon leakage: if economic activity relocates, emissions will move abroad too (e.g. Babiker, 2005).6 Two factors have to converge for competitiveness to be an issue. First, the decarbonization costs in an industry must be

high relative to its output. Second, affected sectors must be subject to international competition. Competitiveness will not

be an issue if only one of these factors is present. The financial sector, for example, is fiercely competitive, but carbon compliance is not a big cost factor. In power gen- eration, decarbonization costs are high, but there is not much international trade. Competitiveness effects are thus not an issue in either sector.

The number of sectors in which the two factors converge is (at least in the UK) relatively small, and they do not account for a large share of employment and gross domestic product (GDP), although they can be important locally. Solutions can therefore be targeted and tailor-made. Among the most vulner- able sectors are steel, basic metals, refined products, and other chemicals. Aluminium production is affected indirectly as it is a large consumer of electricity (Carbon Tmst, 2008).

The currently preferred solution to help these sectors is to offer them free emission allowances if they are subject to a carbon trading scheme. The economic logic of such a lump-sum transfer is unclear, as it only affects long-term location decisions, and not how intensively a plant is run in the short term. In a similar vein, the UK offers firms a discount from the Climate Change Levy if they agree voluntary stan- dards. These climate change agreements have been found to be relatively weak (Martin et al., 2009). If they were not, competitiveness would still be an issue.

Unfortunately, superior alternatives to free permits have often been difficult to implement. The best solution would be a set of international standards for the relevant sectors, but this may be as hard to agree as an overarching climate treaty. Border

adjustments, such as a carbon tax on imports, can be jus- tified economically (e.g. Pigouvian taxes levied at consumer or intermediary level; see Ismer & Neuhoff, 2007). However, their application in practice would almost certainly be difficult. Although it is likely that they are consistent with World Trade Organization rules, they would inevitably be con- tested in a lengthy and costly legal battle.

Another corollary to the competitiveness debate is the discussion on low-carbon jobs. Policy makers make much of the potential for green jobs because low-carbon electricity generation, for example, tends to use more labour than traditional electric power. However, this would be the wrong perspective to take (Fankhauser, Sehlleier, & Stern, 2008). The high labour input into renewable energy is a reflec- tion of the still high costs of renewables and translates into a low level of labour productivity (and hence wages). This will change as renewables become more cost-competitive. In the meantime the right question for policy makers to ask is not about the number of jobs created, but rather about their attractiveness and the ease with which skills can be transferred into these sectors. Rigidities are likely and may require policy intervention.

5.2. Fiscal balance

In economically difficult times, policy makers wonder about the fiscal effects of climate policy. Although it is right to embed low-carbon policy into the broader macro-economic debate, the tran- sition to a low-carbon economy is about long-term structural change and cuts across the business cycle.

Low-carbon policies can be adjusted to fiscal realities without compromising the carbon targets. During the economic crisis of 2009, the case was made for low-carbon investment to

provide a Keyne- sian 'green fiscal stimulus' to the economy (Bowen &

Stern, 2010; Zenghelis, 2011). The UK was one of many countries that responded, devoting 15% of its then-stimulus package to green causes (HSBC, 2009), although less than this was probably spent in the end.

Subsequently, when concern over the UK's budget deficit initiated a phase of fiscal austerity, pre- viously revenue-neutral carbon policies became revenue-raising. The move towards permit auctioning in the EU ETS was serendipitous, but the Government's decision not to recycle the revenue from the CRC Energy Efficiency Scheme was deliberate. EU ETS auctioning could net the UK Exchequer over ￡2 billion a year between 2013 and 2020 (Cooper & Gmbh, 2011), while the CRC is expected to raise ￡1 billion a year. Internationally, Nordhaus (2010) has long called for a carbon tax as a means to address fiscal imbalances in the US.

5.3. Fuel poverty

In the UK, most of the cost of power sector decarbonization - including the cost of renewable obli- gations, supplier obligations, and the EU ETS - are passed on to consumers through higher electricity prices. This is economically correct as electricity prices should reflect the full cost of electricity, includ- ing any externalities. However, higher energy bills raise concern about the distributional consequences of climate policy. The CCC (CCC, 2011b) has estimated that low-carbon policies and investments will add perhaps 10% to the typical UK fuel (gas and electricity) bill between 2010 and 2020. This is on top of an anticipated rise in international fuel prices, which could have a similar effect on bills.

The rise in energy costs has been seized upon by the (climate-sceptic) popular press, but in reality the instruments to deal with fuel poverty are both known and available. In particular, the successful uptake of basic energy-efficiency options would offset not just the cost effect of green policies but also that of higher fuel prices (CCC, 2011b). Other measures to address fuel poverty include direct income support (e.g. through the existing winter fuel allowance) and block tariffs (an option the UK has not adopted). Neither is perfectly targeted at the fuel poor: winter fuel allowance in the UK is available to all pensioners, whether or not they are fuel poor, while a block tariff would not reach the many poor families who live in houses with above-average energy needs (e.g. large families or the elderly).

The UK defines 'fuel poverty' as spending in excess of 10% of income to obtain a defined level of energy services. This is a relatively crude way of assessing the distributional incidence of low-carbon policies. A more complete assessment would capture both energy use and the indirect effect of higher energy prices on the entire consumption basket (Gough, Abdallah, Johnson, Ryan-Collins, & Smith, 2011). It would also factor in any adjustments in consumption patterns that households might make. For example, many people insulate their homes to enjoy more comfort rather than to reduce bills. Bowen and Rydge (2011) have reported that this 'rebound effect' is particularly pronounced in low-income households.

6. Conclusions

There is much interest in low-carbon and more generally green growth, with a substantial academic literature and an emerging cottage industry in low-carbon growth plans. However, as yet there is little guidance on how a low-carbon growth

strategy might look in concrete policy terms. How the transformation to a low-carbon economy might be achieved in practice has been examined here. Drawing lessons primarily from the UK, the legal prerequisites and policy challenges for low-carbon growth have been explored.

High-level lessons of this kind are not a substitute for detailed policy analysis, but they can never- theless provide useful insights for low-carbon policies in Europe and elsewhere. Five lessons for the low-carbon transition can be adduced.

First, the low-carbon transition needs a solid legal basis. Given its long-term nature, decarbonization policy is prone to time inconsistency problems. Governments will be tempted to postpone difficult measures to the future, particularly in economically hard times. The UK stmcture, with a clear long- term commitment (enshrined in law) and statutory short-term targets that have been recommended and are monitored by an independent body, holds some promise in this respect.

The framework passed its first test in 2011, when a stringent carbon budget for 2023-2027 was adopted, despite opposition in business and finance circles. It is a safe conjecture that the 2023- 2027 budget would look very different if the government had been able to set it alone. However, further and sterner tests will no doubt follow, as carbon budgets get tighter and political commitment begins to wane. The fourth carbon budget, in particular, is subj ect to a review in 2014, shortly before the next general election.

Second, decarbonization requires more than just putting a price on carbon. To achieve low-carbon growth, policy makers must address a complex web of market, investment, and behavioural barriers. This can only be done through a mix of

policies; some of them are generic, and probably already in place (e.g. on local pollution), but many will have to be adjusted or strengthened (e.g. on energy effi- ciency or low-carbon innovation). This raises issues of coordination between the different policy measures. The UK experience shows that the policy landscape can easily become very complex. Third, the low-carbon economy is likely to be a highly electrified economy. Practically, all decarbo- nization strategies have a low-carbon power sector at the core of their plans. Electric power is central because it accounts for a large fraction of total GHG emissions and because clean electricity may be a cost-effective way of decarbonizing other parts of the economy. It is risky to try to pick technology winners, and other solutions (e.g. based on bioenergy) are clearly possible, but the current indication is that the decarbonization of road transport, residential heating, and perhaps parts of industry will be based on low-carbon electricity.

Fourth, the low-carbon transition is primarily a revolution of production, not consumption. Decar- bonization requires a combination of technological (supply-side) innovation and behavioural (demand-side) adjustments. Both will have to be stimulated by policy. Their relative importance varies by sector. Demand-side measures are essential, particularly in energy, but the low-carbon strat- egies discussed in this article suggest that technology will be the dominant factor. Behavioural change plays an important but complementary role, including by ensuring the uptake and acceptance of new technologies such as electric cars.

Fifth, the transition to a low-carbon economy is feasible. It is a matter of policy

competence and pol- itical will, rather than economic impacts or technological feasibility. A credible roadmap for

decarbo- nization has been outlined, one based on known technological solutions and complemented with realistic behavioural adjustments in high-emitting sectors such as electric power, transport, and resi- dential buildings. Reducing emissions in some sectors will be hard, and more research is still needed, in particular in the sectors of aviation, agriculture, and some parts of industry. Indeed, these sectors will take up an increasing share of the remaining emissions headroom.

Moving to a low-carbon economy will not be easy. Neither policy competence nor political will can be taken for granted. Decarbonization will also not be costless. The literature on mitigation costs, as well as its findings (e.g. Edenhofer et al., 2010), remain valid, suggesting that even well-implemented reforms have a cost. But this cost is small relative to the expected trend improvements in income and productivity.

二、文献综述

低碳经济发展模式文献综述 摘要

气候变化已成为当今国际社会的热点和焦点问题,应对气候变化的全球实践催生了低碳经济的理念和发展模式, 低碳经济将推动人类生产和消费方式的重大转变,促进相关领域国际协调机制的改革和创新。目前, 低碳经济受到了国内外学术界的普遍关注, 这一领域的研究取得了重要进展。本文从低碳经济的内涵、特征和发展动因入手,对相关研究成果进行综述, 以现有文献为基础,着重分析低碳经济发展模式、全球机制以及低碳发展模式对中国经济增长的影响,探讨未来低碳经济研究的方向和重点。

关键词: 低碳经济; 气候变化; 碳市场; 文献综述 引言

以“先污染后治理、先开发后保护”为特征的增长方式主导了发达国家的工业化和现代化进程。在要素配置全球化程度不断提高的条

件下,传统的工业化和经济增长方式在世界范围内扩散, 很多发展中国家工业化延续了“高投入、高消耗、高污染”的老路, 经济增长的资源约束和环境污染加剧, 可持续发展等全球性问题日益突出。尽管关于人类生产活动对气候的影响以及全球气候变暖的程度、机理等问题仍存在重大争议,但进入21世纪, 气候变化已成为人类经济和社会发展面临的共同挑战。为应对气候变化,世界各国迫切需要改变对化石能源的依赖, 实现生产和生活方式向低碳化转型。国际金融危机爆发后, 发达国家抓住“气候变暖”、“低碳经济”等概念, 加强政策刺激和国际协调力度, 试图在这些领域占得先机, 以主宰新兴战略性领域的全球治理。目前, 低碳经济不仅已成为各国应对气候变化、转变增长方式的共识, 而且也是国内外学术研究的热点, 相关研究成果非常丰富。本文从低碳经济的内涵、特征和发展动因入手, 着重对低碳经济发展模式、交易方式、全球机制以及低碳模式对中国经济增长的影响等方面的研究成果进行梳理, 分析现有研究存在的问题,探讨这一领域未来的研究方向。

一、低碳经济的内涵、特征及发展动因

低碳经济概念出现于上世纪末、本世纪初, 莱斯特·R.布朗在其《生态经济革命:拯救地球和经济的五大步骤》(1999)一书中描绘了低碳经济概念的雏

形。2003年, 英国政府发布的能源白皮书《我们能源的未来:创建低碳经济》首次在官方文件中提出了低碳经济概念, 将低碳经济阐述为通过更少的自然资源消耗和环境污染获得更多的经济产出。迄今为止, 学术界并未形成低碳经济的统一概念。一些学者将低碳经济视为一种经济形态或发展模式,如庄贵阳把低碳经济定义为“人文发展水平和碳生产力(单位碳排放的经济产出)同时达到一定水平的经济形态,旨在实现控制温室气体排放的全球共同愿景。向低碳经济转型的过程就是低碳发展的过程”。鲍健强等也认为, “表面上低碳经济是为减少温室气体排放所做出的努力, 但实质上, 低碳经济是经济发展方式、能源消费方式、人类生活方式的一次新变革, 它将全方位地改造建立在化石燃料(能源)基础之上的现代工业文明,转向生态经济和生态文明”;另一类观点则将低碳经济从理念上升为规则制度。如李俊峰、马玲娟指出:“它

似乎是一个技术问题,或者经济发展模式问题。然而笔者认为, 它的背后是和联合国宪章、关贸总协定一样,是规制世界发展新格局的又一个新的联合国宪章,一个国家低碳经济战略的制定,可能会像工业革命一样,关乎一个经济体在未来世界经济格局中的地位”。随着相关研究的深入, 低碳经济已不再是一个单一的概念,而成为由碳足迹、低碳能源、低碳技术、低碳产业、低碳生产生活方式、低碳城市和低碳社会等一系列新名词支撑的体系。尽管对低碳经济概念的阐述不尽相同,但以低消耗、低排放、高产出的增长模式为核心,涵盖了从原料开采、加工、使用和消费的各个过程, 特别是低碳技术的开发和应用、低碳产品的生产和消费, 以及低碳能源开发和利用的低碳经济内涵被普遍接受(张世秋, 2008)。

二、低碳经济发展模式:技术与政策

低碳经济的发展模式即运用低碳经济理论组织经济活动, 用低碳技术改造生产和生活方式, 从而实现经济发展的低碳化。付允等(2008)从宏观、中观和微观三个层次论证了低碳经济发展模式是以低碳发展为发展方向, 以节能减排为发展方式, 以碳中和技术为发展方法的绿色经济发展模式;朱四海(2009)则从人为碳通量、碳预算、低碳技术、能源结构四个方面构建低碳经济发展模式。从其发展动因出发,可以很好地理解低碳经济发展模式:当气候变化、资源约束上升为影响经济社会发展的重要因素时, 世界各国必然寻求突破资源约束、实现低碳排放与经济增长双赢的低碳经济发展模式, 而这一新型模式的实践是以技术和制度创新为支撑的。

1低碳技术开发应用及其对低碳经济发展模式的作用

广义的低碳技术涵盖了电力、交通、建筑、冶金、化工、石化等部门和能源等领域开发利用的减排技术,也可分类为温室气体的捕集技术、温室气体的埋存技术、低碳或零碳新能源技术(付永等,2008)。近年来, 各国不断加大低碳技术的研发, 并更加注重其经济性。IEA、IPCC、OECD等国际机构对涉及电力、工业、建筑和交通这四个重要部门的核心低碳技术的概念、特征、成本收益、技术现状、工业应用和商业项目、产业链、减排潜力、现存困难等问题等进行了深入研究,制定出

同减排情景下技术路线图, 着重强调碳捕获与封存技术(CCS, Carbon Capture＆Storage)、新型生物质能、太阳能、核电技术以及智能电网等绿色技术的应用。其中, CCS技术因其本身的复杂性、减排潜力大以及对生产方式、产业结构和国际竞争力的影响突出, 成为学者们关注的重点, 相关研究主要集中在CCS的技术经济分析、该技术在产业和国家层面的应用以及CCS商业化、规模化发展的障碍等方面。尽管CCS技术在降低整体减排成本、提高减排灵活性等方面的潜力巨大,（完整内容请到）但现阶段