Market Forces

PBS NewsHour: The economic options for combatting climate change

As greenhouse gases accumulate and global temperatures slowly rise, what can we do to insure against the catastrophes of climate change? Economics correspondent Paul Solman talks to the authors of Climate Shock.

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The holy grail of climate economics? A price on carbon.

(This blog post was co-authored with Dominic Watson and originally posted on EDF Voices.)

If there were a competition for the most important number in the world, the price on carbon would certainly be a strong contender.

The World Bank has been a long-time supporter of carbon pricing and its recent report, Decarbonizing Development, adds a strong voice to the chorus of climate policy experts, economists, and business leaders who champion the economic, social and environmental benefits of pricing pollution.

The report underscores the importance of getting the economics of climate change policies right so we can transition cost-effectively to a carbon-neutral economy.

Because we live in a world of ‘bottom-up’ climate policy, the authors rightfully say, this will require multi-pronged policy solutions, each tailored to a country’s particular economic and political conditions.

At the heart of this broader approach, however, lies the holy grail of climate economics: a price on carbon.

Markets bring results – fossil fuel subsidies don’t

Global temperatures must stay below the 2°C threshold for the world to avoid catastrophic climate change. This requires that net carbon emissions are reduced to zero by the middle to the end of the century.

A price on pollution has been shown time and time again to be the most cost-effective way to reduce emissions. By internalizing the cost of pollution to firms – meaning, making polluters pay for the right to emit carbon – they will have an incentive to reduce emissions and look for the cheapest emissions reduction options.

A tax on carbon, or a cap-and-trade system where permits – or allowances to emit carbon – are auctioned to firms, have the added benefit of bolstering government coffers. The additional revenue can be used to, for example, offset costs low-income households incur should power rates or costs on goods rise.

It can also be used to reduce taxes, including taxes on labor and capital that can affect social welfare and create market inefficiencies.

The World Bank reminds us that getting the price right will include removing costly subsidies on fossil fuels – now estimated at $548 billion worldwide. In addition to encouraging the overconsumption of fossil fuels, these subsidies have proven ineffective for helping the poor or for promoting competitiveness.

A mix of policies can boost clean energy

A comprehensive climate policy package should include a mix of additional policies to help address other market failures, the report notes. Policy makers can help boost innovation in clean technologies, for example, by supplementing a carbon price with temporary support for investments, targeted subsidies, performance standards and technology mandates.

Case in point: California’s AB 32 program, which guarantees emissions reductions through a market based cap-and-trade program while supplementing the cap with a range of statewide regulations.

Among other things, the legislation incentivizes utilities to invest in renewables and requires building, vehicle and appliance efficiency standards that help consumers save on their electricity bills.

Next: A global price on carbon

Some countries may choose to rely on such regulatory measures alone and opt out of market-based solutions for the time being. Such policies will certainly bring countries closer to meeting their emissions goals.

In the long-term, however, a carbon price must form the linchpin of any viable national emissions reduction plan.

And ultimately, if we’re to meet that net-zero carbon emissions goal in the most cost-effective way, all countries should face the same global carbon price.

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When dealing with global warming, the size of the risk matters

Shortly after September 11, 2001, Vice President Dick Cheney gave us what has since become known as the One Percent Doctrine: “If there’s a 1% chance that Pakistani scientists are helping al-Qaeda build or develop a nuclear weapon, we have to treat it as a certainty in terms of our response.”

It inspired at least one book, one war, and many a comparison to the “precautionary principle” familiar to most environmentalists. It’s also wrong.

One percent isn’t certainty. This doesn’t mean that we shouldn’t take the threat seriously, or that the precautionary principle is wrong, per se. We should, and it isn’t.

Probabilities matter.

Take strangelets as one extreme. They are particles with the potential to trigger a chain reaction that would reduce the Earth to a dense ball of strange matter before it explodes, all in fractions of a second.

That’s a high-impact event if there ever was one. It’s also low-probability. Really low probability.

At the upper bound, scientists put the chance of this occurring at somewhere between 0.002% and 0.0000000002% per year, and that’s a generous upper bound.

That’s not nothing, but it’s pretty close. Should we be spending more on avoiding their creation, or figuring out if they’re even theoretically possible in the first place? Sure. Should we weigh the potential costs against the social benefit that heavy-ion colliders at CERN and Brookhaven provide? Absolutely.

Should we “treat it as a certainty” that CERN or Brookhaven are going to cause planetary annihilation? Definitely not.

Move from strangelets to asteroids, and from a worst-case scenario with the highest imaginable impact, but a very low probability, to one with significantly higher probability, but arguably much lower impact.

Asteroids come in all shapes and sizes. There’s the 20-meter wide one that unexpectedly exploded above the Russian city of Chelyabinsk in 2013, injuring mored than 1,400 people. And then there are 10-kilometer, civilization-ending asteroids.

Size matters.

No one would ask for more 20-meter asteroids, but they’re not going to change life on Earth as we know it. We’d expect a 10-kilometer asteroid, of the type that likely killed the dinosaurs 65 million years ago, once every 50-100 million years. (And no, that does not mean we are ‘due’ for one. That’s an entirely different statistical fallacy.)

Luckily, asteroids are a surmountable problem. Given $2 to $3 billion and 10 years, a National Academy study estimates that we could test an actual asteroid-deflection technology. It’s not quite as exciting as Bruce Willis in Armageddon, but a nuclear standoff collision is indeed one of the options frequently discussed in this context.

That’s the cost side of the ledger. The benefits for a sufficiently large asteroid would include not destroying civilization. So yes, let’s invest the money. Period.

Somewhere between strangelets and asteroids rests another high-impact event. Unchecked climate change is bound to have enormous consequences for the planet and humans alike. That much we know.

What we don’t know — at least not with certainty — could make things even worse. The last time concentrations of carbon dioxide stood where they are today, sea levels were up to 20 meters higher than today. Camels lived in Canada. Meanwhile global average surface temperatures were only 1 to 2.5 degrees Celsius (1.8 to 4.5 degrees Fahrenheit) above today’s levels.

Now imagine what the world would like with temperature of 6 degrees Celsius (11 degrees Fahrenheit) higher. There’s no other way of putting it than to suggest this would be hell on Earth.

And based on a number of conservative assumptions, my co-author Martin L. Weitzman and I calculate in Climate Shock that there might well be a 10% chance of an eventual temperature increase of this magnitude happening without a major course correction.

That’s both high-impact and high-probability.

Mr. Cheney was wrong in equating 1% to certainty. But he would have been just as wrong if he had said: “One percent is basically zero. We should just cross our fingers and hope that luck is on our side.”

So what to do? In short, risk management.

We insure our homes against fires and floods, our families against loss of life, and we should insure our planet against the risk of global catastrophe. To do so, we need to act — rationally, deliberately, and soon. Our insurance premium: put a price on carbon.

Instead of pricing carbon, governments right now even pay businesses and individuals to pump more carbon dioxide into the atmosphere due to various energy subsidies, increasing the risk of a global catastrophe. This is crazy and shortsighted, and the opposite of good risk management.

All of that is based on pretty much the only law we have in economics, the Law of Demand: price goes up, demand goes down.

It works beautifully, because incentives matter.

Gernot Wagner serves as lead senior economist at the Environmental Defense Fund and is co-author, with Harvard’s Martin Weitzman, of Climate Shock (Princeton, March 2015). This op-ed first appeared on Mashable.com.

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Big Rigs: Will the Climate Benefit from Switching Diesel Trucks to Natural Gas?

Originally posted on EDF’s Energy Exchange.

16058670001_80994ae935_zThe surge in natural gas production that has reshaped the American energy landscape has many in the commercial transportation sector considering whether to start shifting their heavy-duty vehicle fleets from diesel to natural gas fuel. Many are looking to an advantage in carbon dioxide emissions to justify the higher cost and reduced fuel efficiency of a natural gas vehicle.

But in fact, a study published today in Environmental Science & Technology finds that while there are pathways for natural gas trucks to achieve climate benefits, reductions in potent heat trapping methane emissions across the natural gas value chain are necessary, along with engine efficiency improvements. If these steps are not taken, switching truck fleets from diesel to natural gas could actually increase warming for decades.

Methane, the main ingredient in natural gas, has 84 times more warming power than CO2 over a 20-year timeframe. Reducing emissions throughout the natural gas value chain is an important opportunity to reduce our overall greenhouse footprint.

Growing Body of Research

The new study examines several different types of engine technologies, and both liquefied and compressed natural gas fuels, and concludes that a conversion from diesel could lead to greater warming over the next 50 to 90 years before providing benefits to the climate.

These results align with an earlier paper published by EDF scientists in 2012 in the Proceedings of the National Academy of Sciences (PNAS), but reach these conclusions through updated and more detailed data, as well as analysis tackling a wider scope of vehicle sizes, engine technologies, and fuel types.

Pathway to Positive Climate Benefits

By examining a range of assumptions, the new study finds there are indeed pathways for heavy duty natural gas vehicles to achieve climate benefits, provided methane emissions across the value chain are reduced both upstream and at the vehicle level.

Improvements in fuel efficiency could help ensure these vehicles are climate friendly. Today’s natural gas truck engines are typically five to fifteen percent less efficient than diesel engines. Consuming more fuel for each mile traveled reduces the relative CO2 savings. If that efficiency gap can be closed, natural gas trucks will fare that much better compared to diesel.

Upcoming Policy Opportunities

While emissions in the natural gas value chain are a serious challenge, they also represent an opportunity to achieve significant, cost-effective reductions in overall greenhouse gas emissions. Several policy mechanisms are in play that could improve the climate prospects of natural gas trucks. These include recently announced federal upstream methane regulations and upcoming federal fuel efficiency and greenhouse gas standards for heavy trucks.

More information is needed to estimate with confidence the current climate footprint of trucks, and to get a better understanding of methane loss along the natural gas value chain. Significant research is underway to update estimates of methane emissions across the U.S. natural gas system, including the ambitious scientific research effort to publish 16 field studies launched by EDF and its partners.

Advancing Understanding

The paper released today is distinct from this ongoing effort and does not use any data from those studies, but it serves complementary purposes: First, it emphasizes the importance of gathering more and better data on methane loss; second, one of its major contributions is the various “sensitivity analyses” it presents.

These ranges of potential results are designed to understand the implications of changing underlying assumptions about methane emissions and efficiency. Our new paper creates a framework to evaluate the climate impacts of a fuel switch to natural gas in the trucking sector as we gain better data on the magnitude and distribution of leakage and as both leakage and vehicle efficiency evolve due to policy changes and market dynamics.

Policymakers wishing to address climate change should use caution before promoting fuel switching to natural gas in the trucking sector until we are more certain about the magnitude of methane loss and have acted sufficiently to reduce emissions and improve natural gas engine efficiency.

For more detail on the paper released today, please see our Frequently Asked Questions.

Image Source: Flickr/TruckPR

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Fossil fuels haven’t lost the race, yet. Here’s the full story.

Source: Flickr/Nick HumphriesA recent Bloomberg New Energy Finance article made a splash saying that fossil fuels “just lost the race against renewables.” It included a striking chart, depicting changes in power capacity additions with very clear diverging trends.

Although this would be a delightful turn of events, we should be wary of putting the cart before the horse.

What may be lost on many readers is the fact that Bloomberg bases its story on power capacity, rather than actual power generation. Read More »

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New Climate-Economic Thinking

By Gernot Wagner and Martin L. Weitzman

Each ton of carbon dioxide emitted into the atmosphere today causes about $40 worth of damages. So at least says standard economic thinking.

A lot goes into calculating that number. You might call it the mother of all benefit-cost analyses. It’s bean-counting on a global scale, extending out decades and centuries. And it’s a process that requires assumptions every step along the way.

The resulting $40 figure should be taken for what it is: the central case presented by the U.S. Government Interagency Working Group on Social Cost of Carbon when using its preferred 3% discount rate for all future climate damages. But it is by no means the full story.

Choose a different discount rate, get a different number. Yale economist Bill Nordhaus uses a discount rate of slightly above 4%. His resulting price is closer to $20 per ton of carbon dioxide. The Stern Review on the Economics of Climate Change uses 1.4%. The resulting price per ton is over $80.

And the discount rate is not the only assumption that makes this kind of a difference. In Climate Shock, we present the latest thinking on why and how we should worry about the right price for each ton of carbon dioxide, and other greenhouse gases, emitted into the atmosphere. There are so many uncertainties at every step—from economic projections to emissions, from emissions to concentrations, from concentrations to temperatures, and back to economics in form of climate damages—that pointing to one single, final number is false precision, misleading, or worse.

Of course, that does not mean that we shouldn’t attempt to make this calculation in the first place. The alternative to calculating the cost of carbon is to use a big fat zero in government benefit-cost calculations. That’s clearly wrong.

Most everything we know about what goes into calculating the $40 figure leads us to believe that $40 is the lower bound for sensible policy action. Most everything we know that is left out would push the number higher still, perhaps much higher.

It’s not over ’til the fat tail zings

As just one example, zero in on the link between carbon concentrations in the atmosphere and eventual temperature outcomes. We know that increasing concentrations will not decrease global temperatures. Thank you, high school chemistry and physics. The lower bound for the temperature impact when carbon concentrations in the atmosphere double can be cut off at zero.

In fact, we are pretty sure it can be cut off at 1°C or above. Global average temperatures have already warmed by over 0.8°C, and we haven’t even doubled carbon concentrations from preindustrial levels. Moreover, the temperature increases in this calculation should happen ‘eventually’—over decades and centuries. Not now.

What’s even more worrying is the upper tail of that temperature distribution. There’s no similarly definitive cut-off for the worst-case scenario. In fact, our own calculations (based on an International Energy Agency (IEA) scenario that greenhouse gas concentrations will end up around 700 parts per million) suggest a greater-than-10% chance of eventual global average warming of 6°C or above.

Focus on the bottom row in this table. If you do, you are already ahead of others, most of whom focus on averages, here depicted as “median Δ°C” (eventual changes in global average surface temperatures). The median is what we would expect to exceed half the time, given particular greenhouse gas concentrations in the atmosphere. And it’s bad enough.

But what really puts the “shock” into Climate Shock is the rapid increase in probabilities of eventual temperatures exceeding 6°C, the bottom row. While average temperatures go up steadily with rising concentrations, the chance of true extremes rises rapidly:

Climate Shock Table 3.1

That 6°C is an Earth-as-we-know-it-altering temperature increase. Think of it as a planetary fever. Normal body temperatures hover around 37°C. Anything above 38°C and you have a fever. Anything above 40°C is life-threatening.

Global average warming of 3°C wouldn’t be unprecedented for the planet as a whole, in all of it geological history. For human society, it would be. And that’s where we are heading at the moment—on average, already assuming some ‘new policies’ to come into play that aren’t currently on the books.

It’s the high-probability averages rather than low-probability extremes that drive the original $40 figure. Our table links greenhouse gas concentrations to worryingly high probability estimates for temperatures eventually exceeding 6°C, an outcome that clearly would be catastrophic for human society as we know it.

Instead of focusing on averages then, climate ought to be seen as a risk management problem. Some greenhouse gas concentration thresholds should simply not be crossed. The risks are too high.

This kind of focus on temperature extremes is far from accepted wisdom. We argue it ought to be.

Gernot Wagner and Martin L. Weitzman are co-authors of Climate Shock (Princeton University Press, 2015). First published by The Institute for New Economic Thinking.

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