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.


Cap-and-Trade versus the Alternatives for U.S. Climate Policy

Let’s credit Senator Lisa Murkowski (R-Alaska) for raising questions in the National Journal about the viability of cap-and-trade versus other approaches for the United States to employ in addressing CO2 and other greenhouse gas emissions linked with global climate change.

Senator Murkowski says that only one approach – cap-and-trade – has received significant attention in the Congress.  Let’s put aside for the moment the fact that most of the 1,428 pages of H.R. 2454 – the American Clean Energy and Security Act of 2009 (otherwise known as the Waxman-Markey bill) – are not about cap-and-trade at all, but about a host of other regulatory approaches (several of which are highly problematic, as I’ve discussed in a previous post).  We can also put aside the fact that both conventional regulatory approaches and carbon taxes have been discussed repeatedly in numerous House and Senate committees over the past decade, and received detailed attention from a succession of U.S. administrations.

So, let’s not quibble about the Senator’s claim that cap-and-trade is the only approach that has received serious attention.  Instead, let’s address the key substantive questions which Senator Murkowski raises, because they are important questions:  Is cap-and-trade the most effective way of addressing climate change?  And are there other approaches capable of achieving the same results at lower cost?  From my perspective, as a card-carrying environmental economist, these are indeed the key questions.

While political leaders in the European Union, Canada, Australia, New Zealand, Japan, and the United States (Congress) move toward cap-and-trade systems as their preferred approach for achieving meaningful reductions in emissions of CO2 and other greenhouse gases, many people – including some of my fellow economists — have been critical of the cap-and-trade approach in the climate context and have endorsed the use of carbon taxes.  The Senator is correct that we should reflect on the merits of that alternative approach.

But, first, what about conventional regulatory approaches, that is, performance standards and technology standards?

Conventional Regulatory Standards

In short, experience has shown that such standards cannot ensure achievement of emissions targets, create problematic unintended consequences, and are very costly for what they achieve.

Why can conventional standard not ensure achievement of reasonable emissions targets?  First, standards typically focus on new emissions sources, and do not address emissions from existing sources.  Think about greenhouse gas standards for new cars and new power plants, for example.  Second, standards cannot possibly address all types of new sources, given the ubiquity of energy generation and use (and hence CO2 emissions) in a modern economy.  Third, emissions depend upon many factors that cannot be addressed by standards, such as:  emissions from existing sources and unregulated new sources; how quickly the existing capital stock is replaced; the growth in the number of new emissions sources; and how intensively emissions-generating plants and equipment are utilized.

Next, what about those unintended consequences?  First, by reducing operating costs, energy-efficiency standards – for example — can cause more intensive use of regulated equipment (for example, air conditioners are run more often), leading to offsetting increases in emissions — the “rebound effect.”  Second, firms and households may delay replacing existing equipment if standards make new equipment more costly.  This is the well-known problem with vintage-differentiated regulations or “New Source Review.”  Third, standards may encourage counterproductive, unintended shifts among regulated activities (for example, from purchasing cars to purchasing SUVs under the CAFE program).  All of these unintended consequences result from the problematic incentives that standards can create, compared with the efficient incentives created by a cap-and-trade system (or a carbon-tax, for that matter).

If you favor a regulatory approach, then you may welcome what’s coming from EPA as a result of the Supreme Court ruling of a few years ago combined with the Administration’s endangerment finding.  For my part, I don’t welcome it; I worry about it, because the set of regulatory approaches that could be forthcoming will accomplish relatively little, do so at an unnecessarily high cost, and hence play into the hands of opponents of progressive climate policy.  (More about that in some other, future post.)

Putting a Price on Carbon

To virtually all participants in the policy world, it has become increasingly clear that the only approach that can do the job and do it cost-effectively is one which involves at its core putting a price on carbon.  That leaves cap-and-trade and carbon taxes.  Let me take these in turn.


Let’s step back from the debate regarding the details of the Waxman-Markey House bill or the new Senate proposal by Senators Boxer and Kerry, and think about the essence of the cap-and-trade approach.  (For some of those details, however, please see my previous posts, where I have commented on various aspects of Waxman-Markey and described a proposal I developed for The Hamilton Project of an up-stream, economy-wide CO2 cap-and-trade system to cost-effectively achieve meaningful greenhouse gas emissions reductions.)

Here are the basics.  First, aggregate emissions from regulated sources are capped, and the cap is enforced through a requirement for affected firms to hold emissions allowances.  Importantly, allowance trading minimizes costs of meeting the cap.  It does this because allowances migrate to the highest-valued uses, covering emissions that are the most costly to reduce.  So, the emission reductions undertaken are those that are least costly to achieve.  In essence, the uniform market price of allowances creates incentives for all covered sources to reduce all emissions, and do so cost-effectively.

A cap-and-trade system can be more environmentally-effective and more cost-effective than standards.  First, in terms of environmental-effectiveness, a cap-and-trade system can ensure achievement of emissions targets.  Cap-and-trade allows policymakers to set specific overall emissions targets.  And a well-enforced system guarantees achievement of those targets, because emissions will not exceed available allowances.  An economy-wide, upstream cap-and-trade system on the carbon content of fossil fuels can cover all fossil-fuel-related CO2 emissions without needing to regulate each emissions source individually.

In terms of cost-effectiveness, a well-designed cap-and-trade system minimizes emission reduction costs.  Unlike NOx, SO2, and other pollutants, GHG emission reductions have the same effect no matter how, where, or when they are achieved.  This makes the climate change problem unique in the degree to which compliance flexibility can be used to lower costs without compromising environmental integrity.  Hence, a cap-and-trade system can minimize costs while still meeting environmental objectives by offering three forms of flexibility: what flexibility; where flexibility; and when flexibility.

In regard to “what flexibility,” many types of actions offer low-cost emission reductions, and a cap-and-trade system allows emission reductions through whatever measures are least costly.  By contrast, standards can target only certain identified emission reduction measures, leaving other cost-effective opportunities untapped.  Furthermore, predictions of what measures are cost-effective may be wrong.

In regard to “where flexibility,” the costs of emission reductions vary widely across industries, across facilities, and even across users of the same equipment.  A cap-and-trade system exploits this variation in costs by achieving reductions wherever they are least costly.  By contrast, standards would only be cost-effective if they accounted for all of the variation in costs across sectors, technologies, and regulated entities — but it is completely infeasible for standards to do this.  Emission reduction costs across sectors and technologies change over time, making the flexibility offered by a cap-and-trade system even more valuable.  Also, lower-cost opportunities to reduce emissions may exist in other countries.  Importantly, a cap-and-trade system creates a common currency (emissions allowances) that makes it possible to link with other systems.

A cap-and-trade system also minimizes costs through “when flexibility.”  Costs can be reduced through flexibility in the timing of emission reductions by avoiding:  premature retirement of capital stock or lock-in of existing technologies; and unnecessarily costly reductions in one year due to unusual circumstances when less-costly offsetting reductions can be achieved in other years.  A cap-and-trade can incorporate “when flexibility”
without compromising cumulative emissions targets through: allowance banking and borrowing; and multi-year compliance periods.

Beyond such “static cost-effectiveness,” cap-and-trade creates incentives for technology innovation, and thereby lowers long-run costs.  By rewarding any means of reducing emissions, a cap-and-trade system provides broad incentives for any innovations that lower the cost of achieving emissions targets.  Although standards may encourage development of lower cost means of meeting the standards’ specific requirements, they do not encourage efforts to exceed those standards.

Several cap-and-trade systems have been successful at achieving environmental goals and cost savings:  the phase-out of leaded gasoline in the 1980s; the phase-out of ozone depleting substances; and the Clean Air Act amendments of 1990 SO2 allowance trading program to cut acid rain by 50%.  Perceived shortcomings in other cap-and-trade systems reflect design choices, not problems with the policy instrument itself.  This applies both to California’s RECLAIM program, and the pilot phase of the EU Emissions Trading Scheme (which is operating successfully in its real, Kyoto phase).

In summary, compared with conventional standards, a cap-and-trade system can be more environmentally-effective and more cost-effective.  As with any policy instrument, however, careful design is important.

Taxing Carbon

As I mentioned, it is clear that the only approach that can do the job and do it cost-effectively is one that involves putting a price on carbon.  So, what about the other carbon-pricing approach — a carbon tax?

I am by no means opposed to the notion of a carbon tax, having written about such approaches for more than twenty years.  Indeed, both cap-and-trade and carbon taxes are good approaches to the problem; they have many similarities, some tradeoffs, and a few key differences.   I am opposed, however, to the confused and misleading straw-man arguments that have sometimes been used against cap-and-trade by carbon-tax proponents.

While there are tradeoffs between these two principal market-based instruments targeting CO2 emissions — a cap-and-trade system and a carbon tax – the best (and most likely) approach for the short to medium term in the United States is a cap-and-trade system.  I say this based on three criteria:  environmental effectiveness, cost effectiveness, and distributional equity.  So, my position is not capitulation to politics.  On the other hand, sound assessments of environmental effectiveness, cost effectiveness, and distributional equity should surely be made in the real-world political context.

The key merits of the cap-and-trade approach I have described above are, first, the program can provide cost-effectiveness, while achieving meaningful reductions in greenhouse gas emissions levels.  Second, it offers an easy means of compensating for the inevitably unequal burdens imposed by a climate policy.  Third, it provides a straightforward means to harmonize with other countries’ climate policies.  Fourth, it avoids the current political aversion in the United States to taxes.  Fifth, it is unlikely to be degraded – in terms of its environmental performance and cost effectiveness – by political forces. And sixth, this approach has a history of successful adoption and implementation in this country over the past two decades.

Having said this, there are some real differences between taxes and cap-and-trade that need to be recognized.  First, environmental effectiveness:  a tax does not guarantee achievement of an emissions target, but it does provides greater certainty regarding costs.  This is a fundamental tradeoff.  Taxes provide automatic temporal flexibility, which needs to be built into a cap-and-trade system through provision for banking, borrowing, and possibly a cost-containment mechanism.  On the other hand, political economy forces strongly point to less severe targets if carbon taxes are used, rather than cap-and-trade – this is not a tradeoff, and this is why environmental NGOs are opposed to the carbon-tax approach.

In principle, both carbon taxes and cap-and-trade can achieve cost-effective reductions, and – depending upon design — the distributional consequences of the two approaches can be the same.  But the key difference is that political pressures on a carbon tax system will most likely lead to exemptions of sectors and firms, which reduces environmental effectiveness and drives up costs, as some low-cost emission reduction opportunities are left off the table.  But political pressures on a cap-and-trade system lead to different allocations of allowances, which affect distribution, but not environmental effectives, and not cost-effectiveness.

Proponents of carbon taxes worry about the propensity of political processes under a cap-and-trade system to compensate sectors through free allowance allocations, but a carbon tax is sensitive to the same political pressures, and may be expected to succumb in ways that are ultimately more harmful:  reducing environmental achievement and driving up costs.

The Bottom Line

The Hamilton Project staff concluded in an overview paper (which I highly recommend) that a well-designed carbon tax and a well-designed cap-and-trade system would have similar economic effects.  Hence, they said, the two primary questions to use in deciding between them should be:  which is more politically feasible; and which is more likely to be well-designed?

The answer to the first question is obvious; and I have argued here that given real-world political forces, the answer to the second question also favors cap-and-trade.  In other words, it is important to identify and design policy that will be “optimal in Washington,” not just from the perspective of Cambridge, New Haven, or Berkeley.

In “policy heaven,” the optimal instrument to address climate-change emissions may well be a carbon tax (largely because of its simplicity), but in the real world in which policy is developed and implemented, cap-and-trade is the best approach if one is serious about addressing the threat of climate change with meaningful, effective, and cost-effective policies.