The Promise and Problems of Pricing Carbon

Friday, October 21st was a significant day for climate change policy worldwide and for the use of market-based approaches to environmental protection, but it went largely unnoticed across the country and around the world, outside, that is, of the State of California.  On that day, the California Air Resources Board voted unanimously to adopt formally the nation’s most comprehensive cap-and-trade system, intended to provide financial incentives to firms to reduce the state’s greenhouse gas (GHG) emissions, notably carbon dioxide (CO2) emissions, to their 1990 level by the year 2020, as part of the implementation of California’s Assembly Bill 32, the Global Warming Solutions Act of 2006.  Compliance will begin in 2013, eventually covering 85% of the state’s emissions.

This policy for the world’s eighth-largest economy is more ambitious than the much heralded (and much derided) Federal policy proposal – H.R. 2454, the Waxman-Markey bill – that was passed by the U.S. House of Representatives in June of 2009, and then died in the U.S. Senate the following year.  With a likely multi-year hiatus on significant climate policy action in Washington now in place, California’s system – which will probably link with similar cap-and-trade systems being developed in Ontario, Quebec, and possibly British Columbia – will itself become the focal point of what may evolve to be the “North American Climate Initiative.”

The Time is Ripe for Reflection

California’s formal adoption of its CO2 cap-and-trade system is an important milestone on the multinational path to carbon pricing policies, and signals that the time is ripe to reflect on the promise and problems of pricing carbon, which is the title of a new paper that Joe Aldy and I have written for a special issue of the Journal of Environment and Development edited by Thomas Sterner and Maria Damon on “Experience with Environmental Taxation” (“The Promise and Problems of Pricing Carbon:  Theory and Experience,” October 27, 2011).  [For anyone who is not familiar with my co-author, let me state for the record that Joseph Aldy is an Assistant Professor of Public Policy at the Harvard Kennedy School, having come to Cambridge, Massachusetts, from Washington, D.C., where he served, most recently, during 2009 and 2010, as Special Assistant to the President for Energy and Environment.  Before that, he was a Fellow at Resources for the Future, the Washington think tank.]

Why Price Carbon?

In a modern economy, nearly all aspects of economic activity affect greenhouse gas – in particular, CO2 – emissions.  Hence, for a climate change policy to be effective, it must affect decisions regarding these diverse activities.  This can be done in one of three ways:  mandating that businesses and individuals change their behavior; subsidizing businesses and individuals; or pricing the greenhouse gas externality.

As economists and virtually all other policy analysts now recognize, by internalizing the externalities associated with CO2 emissions, carbon pricing can promote cost-effective abatement, deliver powerful innovation incentives, and – for that matter – ameliorate rather than exacerbate government fiscal problems.  [See the concise and compelling argument made by Yale Professor William Nordhaus in his essay, “Energy:  Friend or Enemy?” in The New York Review of Books, October 27, 2011.]

By pricing CO2 emissions (or, more likely, by pricing the carbon content of the three fossil fuels – coal, petroleum, and natural gas), governments wisely defer to private firms and individuals to find and exploit the lowest cost ways to reduce emissions and invest in the development of new technologies, processes, and ideas that could further mitigate emissions.

Can Market-Based Instruments Really Work?

Market-based instruments have been used with considerable success in other environmental domains, as well as for pricing CO2 emissions.  The U.S. sulfur dioxide (SO2) cap-and-trade program cut U.S. power plant SO2 emissions more than 50 percent after 1990, and resulted in compliance costs one half of what they would have been under conventional regulatory mandates.

The success of the SO2 allowance trading program motivated the design and implementation of the European Union’s Emission Trading Scheme (EU ETS), the world’s largest cap-and-trade program, focused on cutting CO2 emissions from power plants and large manufacturing facilities throughout Europe.  The U.S. lead phase-down of gasoline in the 1980s, by reducing the lead content per gallon of fuel, served as an early, effective example of a tradable performance standard.  These and other positive experiences provide motivation for considering market-based instruments as potential approaches to mitigating GHG emissions.

What Policy Instruments Can be Used for Carbon Pricing?

In our paper, Joe Aldy and I critically examine the five generic policy instruments that could conceivably be employed by regional, national, or even sub-national governments for carbon pricing:  carbon taxes, cap-and-trade, emission reduction credits, clean energy standards, and fossil fuel subsidy reduction.  Having written about these approaches many times in previous essays at this blog, today I will simply direct the reader to those previous posts or, better yet, to the paper we’ve written for the Journal of Environment and Development.

Although it is natural to think and talk about carbon pricing using the future tense, a few carbon pricing regimes are already in place.

Regional, National, and Sub-National Experiences with Carbon Pricing

Explicit carbon pricing policy regimes currently in place include the European Union’s Emissions Trading Scheme (EU ETS); the Regional Greenhouse Gas Initiative in the northeast United States; New Zealand’s cap-and-trade system; the Kyoto Protocol’s Clean Development Mechanism; a number of northern European carbon tax policies; British Columbia’s carbon tax; and Alberta’s tradable carbon performance standard (similar to a clean energy standard).  We describe and assess all of these in our paper.

Also, the Japanese Voluntary Emissions Trading System has operated since 2006 (Japan is considering a compulsory emissions trading system), and Norway operated its own emissions trading system for several years before joining the EU ETS in 2008.  Legislation to establish cap-and-trade systems is under debate in Australia (combined with a carbon tax for an initial three-year period) and in the Canadian provinces of Ontario and Quebec.  And, of course, California is now committed to launching its own GHG cap-and-trade system.

International Coordination Will Be Needed

Of course, climate change is truly a global commons problem:  the location of greenhouse gas emissions has no effect on the global distribution of damages.  Hence, free-riding problems plague unilateral and multilateral approaches, because mitigation costs are likely to exceed direct benefits for virtually all countries.  Cost-effective international policies – insuring that countries get the most environmental benefit out of their mitigation investments – will help promote participation in an international climate policy regime.

In principle, internationally-employed market-based instruments can achieve overall cost effectiveness.  Three basic routes stand out.  First, countries could agree to apply the same tax on carbon (harmonized domestic taxes) or adopt a uniform international tax.  Second, the international policy community could establish a system of international tradable permits, – effectively a nation-state level cap-and-trade program.  In its simplest form, this represents the Kyoto Protocol’s Annex B emission targets and the Article 17 trading mechanism.  Third and most likely, a more decentralized system of internationally-linked domestic cap-and-trade programs could ensure internationally cost-effective emission mitigation.  We examine the merits and the problems associated with each of these means of international coordination in the paper.

What Lies in the Future?

In reality, political responses in most countries to proposals for market-based approaches to climate policy have been and will continue to be largely a function of issues and factors that transcend the scope of environmental and climate policy.  Because a truly meaningful climate policy – whether market-based or conventional in design – will have significant impacts on economic activity in a wide variety of sectors and in every region of a country, proposals for these policies inevitably bring forth significant opposition, particularly during difficult economic times.

In the United States, political polarization – which began some four decades ago, and accelerated during the economic downturn – has decimated what had long been the key political constituency in the Congress for environmental action, namely, the middle, including both moderate Republicans and moderate Democrats.  Whereas Congressional debates about environmental and energy policy had long featured regional politics, they are now fully and simply partisan.  In this political maelstrom, the failure of cap-and-trade climate policy in the U.S. Senate in 2010 was essentially collateral damage in a much larger political war.

It is possible that better economic times will reduce the pace – if not the direction – of political polarization.  It is also possible that the ongoing challenge of large budgetary deficits in many countries will increase the political feasibility of new sources of revenue.  When and if this happens, consumption taxes (as opposed to traditional taxes on income and investment) could receive heightened attention, and primary among these might be energy taxes, which can be significant climate policy instruments, depending upon their design.

That said, it is probably too soon to predict what the future will hold for the use of market-based policy instruments for climate change.  Perhaps the two decades we have experienced of relatively high receptivity in the United States, Europe, and other parts of the world to cap-and-trade and offset mechanisms will turn out to be no more than a relatively brief departure from a long-term trend of reliance on conventional means of regulation.  It is also possible, however, that the recent tarnishing of cap-and-trade in U.S. political dialogue will itself turn out to be a temporary departure from a long-term trend of increasing reliance on market-based environmental policy instruments.  It is much too soon to say.


A Wave of the Future: International Linkage of National Climate Change Policies

The latest rage in Washington policy discussions these days (that’s relevant to climate change) is renewed interest in renewable electricity standards, this time in the form of so-called “clean energy standards.”  I’ve written about this policy approach recently at this blog (Renewable Energy Standards: Less Effective, More Costly, but Politically Preferred to Cap-and-Trade?, January 11, 2011), and will do so again in the near future, but for today I want to turn to an important issue – for the long term – on the related topic of the international dimensions of climate change policy.

The Current State of Affairs

Despite the death in the U.S. Senate last year of serious consideration of an economy-wide cap-and-trade system for carbon dioxide (CO2) emissions – and the apparent political hiatus of such consideration at least until after the November 2012 elections – a major cap-and-trade system for greenhouse gas (GHG) emissions is in place in the European Union; similar systems are in place or under development in New Zealand, California, and several Canadian provinces; systems are being considered at the national level in Australia, Canada, and Japan; and a global emission reduction credit scheme – the Clean Development Mechanism (CDM) – has an enthusiastic and important constituency of supporters in the form of the world’s developing countries.

So, despite the fact that there has been an undeniable loss of momentum due to recent political developments in Australia, Japan, and the United States, it remains true that cap-and-trade is still the most likely domestic policy approach for CO2 emissions reductions throughout the industrialized world, given the rather unattractive set of available alternative approaches.  This makes it important to think about the possibility of linking these national and regional cap-and-trade systems in the future.  Such linking occurs when the government that maintains one system allows regulated entities to use allowances or credits from other systems to meet compliance obligations.

Thinking About Linkage

In 2007, with support from the International Emissions Trading Association (IETA) and the Electric Power Research Institute (EPRI), Judson Jaffe and I analyzed the opportunities and challenges presented by linking tradable permit systems.  Jaffe was then at Analysis Group in Boston, and is now at the U.S. Department of the Treasury.  We presented our findings at the thirteenth Conference of the Parties of the U.N. Framework Convention on Climate Change in Bali, Indonesia, in December, 2007.  In 2010, Matthew Ranson (a Ph.D. student in Public Policy at Harvard), Jaffe, and I expanded on these ideas in an article that was published in Ecology Law Quarterly, “Linking Tradable Permit Systems:  A Key Element of Emerging International Climate Policy.” In today’s blog post, I summarize the highlights of this complex, yet important topic.

First, for anyone new to this territory, let me review the basic facts.  Tradable permit systems fall into two categories:  cap-and-trade and emission reduction credits.  Under cap-and-trade (CAT), the total emissions of regulated sources are capped and the sources are required to hold allowances equal to their emissions.  Under a credit system, entities that voluntarily undertake emission reduction projects are awarded credits that can be sold to participants in cap-and-trade systems.

The Merits of Linking

By broadening markets for allowances and credits, linking increases the liquidity and improves the functioning of markets.  Linking can reduce the costs of the linked systems by making it possible to shift emission reductions across systems.  Just as allowance trading within a system allows higher-cost emission reductions to be replaced by lower-cost reductions, trading across systems allows higher-cost reductions in one system to be replaced by lower-cost reductions in another system.

Other Implications

Along with the cost savings it can offer, linking has other implications that warrant serious consideration.  Under some circumstances, linked systems collectively will not achieve the same level of emission reductions as they would absent linking.  This can result either from a link’s impact on emissions under the linked systems, or from its impact on emissions leakage from those systems.  Linking also has distributional impacts across and within systems.  And linking can reduce the control that a country has over the impacts of its tradable permit system.  In particular, when a domestic CAT system is linked with another CAT system, decisions by the government overseeing the other system can influence the domestic system’s allowance price, distributional impacts, and emissions.

By the way, linkage can also occur among a heterogeneous set of domestic policy instruments, including carbon taxes and various types of regulation, although the linking is more challenging under such circumstances.  On this, see “Linking Policies When Tastes Differ: Global Climate Policy in a Heterogeneous World,” a discussion paper by Gilbert Metcalf, Department of Economics, Tufts University,  and David Weisbach, University of Chicago Law School, for the Harvard Project on Climate Agreements.

Concerns About Linking

Importantly, trading brought about by unrestricted links between CAT systems will lead to the automatic propagation of certain design elements, including:  offset provisions and linkages with other systems; banking and borrowing of allowances across time; and safety-valve provisions.  If these provisions, sometimes characterized as cost-containment measures, are present in one of the linked systems, they will automatically be made available to participants in the other system.

In the near-term, some links will be more attractive and easier to establish than others.  Given the design-element propagation implications of two-way links between cap-and-trade systems, to facilitate such links it may be necessary to harmonize some design elements.  And in some cases, it may be necessary to establish broader international agreements governing aspects of the design of linked cap-and-trade systems beyond mutual recognition of allowances.

An Emerging De Facto International Climate Policy Architecture?

Whereas some two-way links between cap-and-trade systems may thus take more time to establish, in the near-term one-way links between cap-and-trade and credit systems likely will be more attractive and easier to establish.  A one-way link with a credit system may offer a cap-and-trade system greater cost savings than a two-way link with another cap-and-trade system.  Also, such one-way links can only reduce allowance prices in the cap-and-trade system, giving a government greater control over its system than if it established a two-way link with another cap-and-trade system.  The additionality problem is an important concern associated with such links, but it can be managed – to some degree – through the criteria established for awarding or recognizing credits.

Most important, if emerging cap-and-trade systems link with a common credit system, such as the CDM, this will create indirect links among the cap-and-trade systems.  Through the indirect links that they create, such one-way linkages can achieve much of the near-term cost savings and risk diversification that direct two-way links among cap-and-trade systems would achieve.  And they can do this without requiring the same foundation that likely would be needed to establish direct two-way links, such as harmonization of cost-containment measures.  Such linkage may well emerge as part of the de facto post-Kyoto international climate policy architecture, and is fully consistent with the bottom-up, decentralized approach of the Cancun Agreements.


For much more detailed discussions, here are some publications available on the web that describe various aspects of linkage:

Jaffe, Judson, Matthew Ranson, and Robert Stavins.  “Linking Tradable Permit Systems:  A Key Element of Emerging International Climate Policy Architecture.” Ecology Law Quarterly 36(2010):789-808.

Jaffe, Judson, and Robert Stavins.  “Linkage of Tradable Permit Systems in International Climate Policy Architecture.” The Harvard Project on International Climate Agreements, Discussion Paper 08-07, Cambridge, Massachusetts, September, 2008.

Jaffe, Judson, and Robert Stavins. Linking a U.S. Cap-and-Trade System for Greenhouse Gas Emissions: Opportunities, Implications, and Challenges. Washington, D.C.: AEI-Brookings Joint Center for Regulatory Studies, January 2008.

Jaffe, Judson, and Robert Stavins.  Linking Tradable Permit Systems for Greenhouse Gas Emissions: Opportunities, Implications, and Challenges. Prepared for the International Emissions Trading Association, Geneva, Switzerland. November, 2007.

Also, this issue of linkage among tradable permit systems has come up previously in a number of my essays at this blog:

AB 32, RGGI, and Climate Change: The National Context of State Policies for a Global Commons Problem

The Real Options for U.S. Climate Policy

What Hath Copenhagen Wrought? A Preliminary Assessment of the Copenhagen Accord

Only Private Sector Can Meet Finance Demands of Developing Countries

Approaching Copenhagen with a Portfolio of Domestic Commitments

Worried About International Competitiveness? Another Look at the Waxman-Markey Cap-and-Trade Proposal


The Real Options for U.S. Climate Policy

The time has not yet come to throw in the towel regarding the possible enactment in 2010 of meaningful economy-wide climate change policy (such as that found in the Waxman-Markey legislation passed by the U.S. House of Representatives in June, 2009, or the more recent Kerry-Lieberman proposal in the Senate).  Meaningful action of some kind is still possible, or at least conceivable.  But with debates regarding national climate change policy becoming more acrimonious in Washington as midterm elections approach, it is important to ask, what are the real options for climate policy in the United States – not only in 2010, but in 2011 and beyond.  That’s the purpose of this essay.

Federal Policy Options

Let’s begin my considering Federal policy options under two distinct categories:  pricing instruments and other approaches.  Carbon-pricing instruments could take the form of caps on the quantity of emissions (cap-and-trade, cap-and-dividend, or baseline-and-credit), or approaches that directly put carbon prices in place (carbon taxes or subsidies).  Beyond pricing instruments, the other approaches include regulation under the Clean Air Act, energy policies not targeted exclusively at climate change, public nuisance litigation, and NIMBY and other public interventions to block permits for new fossil-fuel related investments.  I will discuss each of these in turn.

Quantity-Based Carbon Pricing

I’ve frequently written about cap-and-trade in the past (See, for example:  Here We Go Again: A Closer Look at the Kerry-Lieberman Cap-and-Trade Proposal; Eyes on the Prize:  Federal Climate Policy Should Preempt State and Regional Initiatives; Any Hope for Meaningful U.S. Climate Policy? You be the Judge; Confusion in the Senate Regarding Allowance Allocation?; Cap-and-Trade versus the Alternatives for U.S. Climate Policy; Can Countries Cut Carbon Emissions Without Hurting Economic Growth?; Cap-and-Trade: A Fly in the Ointment? Not Really; National Climate Change Policy: A Quick Look Back at Waxman-Markey and the Road Ahead; Worried About International Competitiveness? Another Look at the Waxman-Markey Cap-and-Trade Proposal; The Wonderful Politics of Cap-and-Trade: A Closer Look at Waxman-Markey; The Making of a Conventional Wisdom), and so I will be very brief on this instrument in this essay.

A Quick Reminder about Cap-and-Trade

In brief, there are four principal merits of the cap-and-trade approach to achieving significant reductions of carbon dioxide (CO2) emissions.  First, this approach achieves overall targets at minimum aggregate cost, that is, it is cost-effective, both in the short term by allocating responsibility among sources, and in the long term, by providing price signals that will drive technological innovation and diffusion of carbon-friendly technologies.  Second, the allowance allocation under a cap-and-trade system can be used to build a constituency of political support across sectors and geographic areas without driving up the cost of the program or reducing its environmental performance.  Third, we have significant experience in the United States with the use of this approach, including during the 1980s to phase out leaded gasoline from the marketplace, and since the 1990s to cut acid rain by 50 percent.  Fourth, and of great importance, a domestic cap-and-trade system can be linked directly and cost-effectively with cap-and-trade systems and emission-reduction-credit systems in other parts of the world to keep costs down domestically.

Three principal concerns have been voiced about cap-and-trade systems in U.S. debates.  First, while a cap-and-trade system constrains the quantity of emissions, the costs of control are left uncertain (although such cost uncertainty can be limited — if not eliminated — through the use of safety valves, price collars, or related mechanisms).  Second, in the wake of concerns regarding the roll that financial markets played in the global recession, there have been many fears about the possibilities of market manipulation in a cap-and-trade system.  A third concern – in a political context – is that this cost-effective approach to environmental protection, pioneered by the Republican administration of President George H. W. Bush, has – ironically — been demonized by conservatives in current debates.

That said, a variety of pending design issues will need to be addressed in the development of any cap-and-trade system, including:  ambition, scope (suddenly important because of a renewed focus in Washington on the possibility of a utility-only cap), point of regulation in the economy, allowance allocation, the role of offsets, cost-containment mechanisms, international competition protection, and regulatory oversight.  (I’ve written about all of these design issues in previous essays at this blog and elsewhere.)

A Design-Change for Cap-and-Trade?

Does the current political climate call for a design change — or at least a name change — for cap-and-trade?   Both stepwise and sectoral approaches are being considered.  A stepwise approach of beginning with one or a few sectors of the economy and subsequently expanding gradually to an economy-wide program was embodied in both the Waxman-Markey legislation and in the Kerry-Lieberman proposal.  Under a sectoral approach, cap-and-trade would be used for some sectors, but other approaches would be used for other parts of the economy.  To some degree, the Kerry-Lieberman proposal embodies this approach.  The current focus in Washington is on the possibility of using cap-and-trade for the electricity sector only.

Although the politics may argue for a stepwise or sectoral approach, it should be recognized that neither is likely to be cost-effective, because it is highly unlikely that marginal abatement costs will be equated across all sectors of the economy without the use of a single (implicit) price on carbon.

So the potential approach now receiving much attention in Washington of employing a cap-and-trade system in the electricity sector only would — in all likelihood — achieve less in terms of overall emissions reductions, and would not be cost-effective (due to the exclusion of other sectors).  However, it is at least conceivable that will prove to be the best among politically-feasible paths to a better future policy.  That is, of course, a political — not an economic — question.

A Populist Approach?

Populism has emerged as a major theme in recent electoral politics in the United States, both from the left and from the right.  What might be characterized as a populist approach would be a cap-and-trade system with 100% of the allowances auctioned and the auction revenue returned directly “to the people.”  Although this is a standard variant of cap-and-trade design, contemporary politics — with its demonization of the phrase “cap-and-trade” — might well argue for a name change:  how about “cap-and-dividend?”

This approach is embodied in the CLEAR Act of Senators Maria Cantwell (D-Washington) and Susan Collins (R-Maine).  The merits of this approach include its simplicity, appearance of fairness, and related appeal to the populist mood.  Concerns, however, include the proposal’s relatively modest environmental achievements (according to an analysis by the World Resources Institute), its overall cost due to restrictions on trading, and its apparent political infeasibility, given its lack of visible support in the Congress.

Other Trading Mechanisms

In addition to cap-and-trade, the other major type of tradable permit system is an emission-reduction-credit system, or baseline-and-credit system.  Because such approaches lack caps, they raise some well-known concerns, in particular the necessity of comparing actual emissions with what emissions would have been in the absence of the policy.  In such a system, the latter is fundamentally unobserved and unobservable.  This is the problem of “additionality,” which comes up in spades in the case of the Clean Development Mechanism (CDM), but also in the context of most other offset programs.

A related trading mechanism is found in the Clean Energy Standards approach, embodied in Senator Richard Lugar’s (R-Indiana) legislative proposal.  This mechanism is similar to a Renewable Portfolio Standard (RPS), but allows for a broader set of qualified sources;  not only renewables, but also nuclear power, fossil fuel power with carbon capture and storage (CCS), and – in principle — efficient natural gas.  If the clean energy credits are denominated in units of carbon free megawatt hours and are tradable, then the merits of this approach include the flexibility that is provided through trading.  The concerns include the lack of an emissions cap, and the difficulty of expanding this approach to other sectors or linking it with a cap-and-trade system.  However, if the clean energy credits are denominated in emissions per megawatt hour, then the program can more easily be converted to or linked with a cap-and-trade system.

Direct Carbon Pricing

A carbon tax system would be similar in design to an upstream cap-and-trade approach.  There is some real interest in this approach, mainly from academics, and there is also what I would characterize as “strategic interest,” principally from those who recognize that once the focus is on carbon taxes rather than other instruments, political debates will inevitably result in less ambitious targets or, in fact, no policy at all.

Carbon Taxes in Brief

Having said this, the merits of a carbon tax approach compared with cap-and-trade include the fact that cost uncertainty is eliminated with the tax approach (although, of course, there is quantity uncertainty, that is, no emissions cap).  And, I mentioned earlier, the cost uncertainty inherent in a cap-and-trade system can be reduced, if not eliminated, with cost-containment mechanisms such as a price collar.

Another merit of the carbon tax approach is that it would generate substantial revenues (as would a cap-and-trade system in which the allowances are auctioned).  These revenues can be used – in principle – for a variety of worthwhile public purposes, including reducing distortionary taxes, which would serve to lower the overall social cost of the policy.  Third, the tax approach is (at least perceived to be) much simpler than the allowance market that would be generated by a cap-and-trade scheme.

Major concerns regarding carbon taxes are fourfold.  First, despite their social cost-effectiveness, pollution taxes can be more costly to the regulated sector than even a non-cost-effective command-and-control instrument.  Second, unlike cap-and-trade, the tax approach lacks a benign mechanism for building political constituency, and is likely to lead to requests for tax exemptions, and hence a less ambitious policy and possibly a more costly one.  Third, although it is not impossible to link such as system internationally (for purposes of cost containment), it is more challenging to do so than with the quantity based cap-and-trade alternative.  A fourth and final concern is the apparent political infeasibility of this approach, at least currently in the United States.

In this regard, it is important to note that what has frequently been interpreted as hostility to cap-and-trade in the U.S. Senate is actually – on closer inspection — broader hostility to the very notion of carbon pricing (or any climate change policy).  Surely, the political reception to a carbon tax would be even less enthusiastic than the reception that has greeted recent cap-and-trade proposals.

Subsidies:  The Good, the Bad, and the Ugly

If it’s so politically difficult to tax “bad behavior,” how about subsidizing “good behavior?”  The mirror image of a tax is indeed a subsidy, and two potential price-based approaches to achieving greenhouse gas emission reductions are the use of climate-friendly subsidies and the elimination of problematic subsidies that exacerbate the climate problem.

In thinking about climate-friendly subsidies, we should first keep in mind that the Obama economic stimulus package enacted by the Congress includes significant subsidies (and tax credits) for renewables and efficiency upgrades — to the tune of about $80 billion.  A major problem has been that the administration (in particular, the Department of Energy) has been finding it difficult to spend the money fast enough.  Also, some would consider subsidies for biofuels, such as ethanol, as falling within this category of climate-friendly subsidies, but clearly that is a matter of considerable controversy.

Principal among the problematic subsidies – and hence major candidates for reduction or elimination – are subsidies for the development and use of fossil fuels.  According to the Environmental Law Institute, U.S. fossil-fuel subsidies and tax breaks currently amount to $8-$10 billon per year.  At the global level, the International Energy Agency has estimated that such fossil-fuel subsidies now amount to $550 billion annually!  President Obama proposed at the G20 meeting in Pittsburgh in November, 2009, that such subsidies be phased out around the world, and there seemed at the time to be broad-based support for this proposal.  However, it should not be surprising that less than a year later, it now appears that the commitment may be watered down somewhat at the G20 meeting in Toronto this June.

The merit of trying to use climate-friendly subsidies is based on the fact that subsidies affect relative prices, much like taxes do, but are much more politically attractive, since politicians prefer to give out benefits rather than costs to their constituents.  And eliminating problematic subsidies can be economically efficient.

But a major concern of using climate-friendly subsidies is that the funds go not only to marginal units that otherwise would not be taking specific actions, but also to infra-marginal units that are pleased to accept the funds, but whose behavior is unaffected by them.  This means that this approach is relatively costly to the government (and to society at large) for what is accomplished.  And a concern of removing fossil fuel subsidies – particularly in the current political climate of worries about oil imports – is that this can work against so-called “energy security” (some have therefore suggested the addition of an “oil import fee”).

Climate Change Regulation under the Clean Air Act

Regulations of various kinds may soon be forthcoming – and in some cases, will definitely be forthcoming – as a result of the U.S. Supreme Court decision in Massachusetts v. EPA and the Obama administration’s subsequent “endangerment finding” that emissions of carbon dioxide and other greenhouse gases endanger public health and welfare.  This triggered mobile source standards earlier this year, the promulgation of which identified carbon dioxide as a pollutant under the Clean Air Act, thereby initiating a process of using the Clean Air Act for stationary sources as well.

Those new standards are scheduled to begin on January 1, 2011, with or without the so-called “tailoring rule” that would exempt smaller sources.  Among the possible types of regulation that could be forthcoming for stationary sources under the Clean Air Act include:  new source performance standards; performance standards for existing sources (Section 111(d)); and New Source Review with Best Available Control Technology standards under Section 165.

The merits that have been suggested of such regulatory action are that it would be effective in some sectors, and that the threat of such regulation will spur Congress to take action with a more sensible approach, namely, an economy wide cap-and-trade system.

However, regulatory action on carbon dioxide under the Clean Air Act will accomplish relatively little and do so at relatively high cost, compared with carbon pricing.  Also, it is not clear that this threat will force the hand of Congress.  Indeed it is reasonable to ask whether this is a credible threat, or will instead turn out to be counter-productive (when stories about the implementation of inflexible, high-cost regulatory approaches lend ammunition to the staunchest opponents of climate policy).

Furthermore, there is the question of possible preemption.  Although Senator Lisa Murkowski’s (R-Alaska) resolution was defeated in the Senate, Senator Jay Rockefeller’s (D-West Virginia) proposal of a two-year delay of Clean Air Act regulatory action is still pending; and depending upon the outcome of the November elections, there may be a series of further Congressional actions to tie the hands of EPA in this regard.

Regulation of Conventional Pollutants under the Clean Air Act

It’s also possible that air pollution policies for non-greenhouse gas pollutants, the emissions of some of which are highly correlated with CO2 emissions, may play an important role.  For example, the three-pollutant legislation co-sponsored by Senator Thomas Carper (D-Delaware) and Senator Lamar Alexander (R-Tennessee), focused on SOx, NOx, and mercury, could have profound impacts on the construction and operation of coal-fired electricity plants, without any direct CO2 requirements.  Beyond this, there are also possibilities of policies for the non-CO2 greenhouse gases.

Important, Unanswered Questions

An important pending question regarding EPA’s use of the Clean Air Act is whether EPA may legally create CO2 cap-and-trade or offset markets under existing Clean Air Act authority.  The answer appears to be “probably yes.”  There is positive precedent from EPA’s emissions trading program of the 1970s, and it’s a leaded gasoline phase-down of the 1980s, although recent court decisions regarding the Bush administration’s Clean Air Interstate Rule may cause concern in this regard.

The more important question, however, may turn out to be whether EPA can politically create significant CO2 markets in the face of Congressional opposition.  The answer to this is considerably less clear.

Energy Policies Not Targeted Exclusively at Climate Change

The “positive politics” generated by the Gulf oil spill, combined with the “negative politics” of addressing climate change explicitly, may well increase the likelihood of so-called “energy-only” legislation being enacted this year.  Senator Jeff Bingaman’s (D-New Mexico) bill from the Environment and Natural Resources Committee and perhaps Senator Richard Lugar’s bill will feature centrally in any bipartisan initiative.

The possible components of such an approach which would be relevant in the context of climate change include:  a national renewable electricity standard; Federal financing for clean energy projects: energy efficiency measures (building, appliance, and industrial efficiency standards; home retrofit subsidies; and smart grid standards, subsidies, and dynamic pricing policies); and new Federal electricity-transmission siting authority.

Other Legal Mechanisms

Even without action by the Congress or by the Administration, legal action on climate policy is likely to take place within the judicial realmPublic nuisance litigation will no doubt continue, with a diverse set of lawsuits being filed across the country in pursuit of injunctive relief and/or damages.  Due to recent court decisions, the pace, the promise, and the problems of this approach remain uncertain.

Beyond the well-defined area of public nuisance litigation, other interventions which are intended to block permits for new fossil energy investments, including both power plants and transmission lines will continue.  Some of these interventions will be of the conventional NIMBY character, but others will no doubt be more strategic.

Does the Road to National Climate Policy Need to Go through Washington?

With political stalemate in Washington, attention may increasingly turn to regional, state, and even local policies intended to address climate change.  The Regional Greenhouse Gas Initiative (RGGI) in the Northeast has created a cap-and-trade system among electricity generators.  More striking, California’s Global Warming Solutions Act (Assembly Bill 32, or AB 32) will likely lead to the creation of a very ambitious set of climate initiatives, including a statewide cap-and-trade system (unless it’s stopped by ballot initiative or a new Governor, depending on the outcome of the November 2010 elections).  The California system is likely to be linked with systems in other states and Canadian provinces under the Western Climate Initiative.

These sub-national policies will interact in a variety of ways – some good, some bad — with Federal policy when and if Federal policy is enacted.  As Professor Lawrence Goulder (Stanford University) and I have written in a new paper for the National Bureau of Economic Research (NBER), some of these interactions could be problematic, such as the interaction between a Federal cap-and-trade system and a more ambitious cap-and-trade system in California under AB 32, while other interactions would be benign, such as RGGI becoming somewhat irrelevant in the face of a Federal cap-and-trade system that was both more stringent and broader in scope.

An important question is whether there can be sensible sub-national policies even in the presence of an economy-wide Federal carbon-pricing regime?  The answer is surely yes, partly because other market failures will continue to exist that are not addressed by carbon pricing.  A prime example is the principal-agent problem of insufficient energy-efficiency investments in renter-occupied properties, even in the face of high energy prices.  This is a problem that is best addressed at the state or even local level, such as through building codes and zoning.

In the meantime, in the absence of meaningful Federal action, sub-national climate policies could well become the core of national action.  Problems will no doubt arise, including legal obstacles such as possible Federal preemption or litigation associated with the so-called Dormant Commerce Clause.  Also, even a large portfolio of state and regional policies will not be comprehensive of the entire nation, that is, not truly national in scope.  And even if they are nationally comprehensive, with different policies of different stringency in different parts of the country, carbon shadow-prices will by no means be equivalent, and so overall policy objectives will be achieved at excessive social cost.

Is there a solution, if only a partial one?  Yes, state and regional carbon markets can be linked.  Such linkage occurs as a result of bilateral recognition of allowances, which results in reduced costs, price volatility, leakage, and market power.  Such bottom-up linkage of state and regional cap-and-trade systems may be an important part or perhaps the core of future of U.S. climate policy, at least until there is meaningful action at the Federal level.  In the meantime, it is at least conceivable that linkage of state-level cap-and-trade systems across the United States will become the de facto post-2012 national climate policy architecture.

The Path Ahead

Conventional politics clearly disfavors market-based (pricing) environmental policy approaches that render costs obvious or at least somewhat transparent, despite the fact that the costs of these same policies are actually less than those of alternative approaches.  Instead, conventional politics favors approaches to environmental protection that render costs less obvious (or better yet invisible), such as renewable portfolio standards, and — for that matter — all sorts of command-and-control performance and technology standards.

But carbon pricing will be necessary to address the diverse economy-wide sources of CO2 emissions effectively and at sensible cost, whether the carbon pricing comes about through an economy-wide Federal cap-and-trade system or through a Federal carbon tax.  It is inconceivable that truly meaningful reductions in CO2 emissions could be achieved through purely regulatory approaches, and it remains true that whatever would be achieved, would be accomplished at excessively high cost.

So, although it is true – as I have sought to explain in this essay – that there are a diverse set of options for future climate policy in the United States, the best available alternative to an economy-wide cap-and-trade system enacted in 2010 may be an economy-wide cap-and-trade system enacted in 2011.  But ultimately, the question of what is the best alternative this year to an economy-wide cap-and-trade system is a political, not an economic question.