A carbon tax may not actually do a whole lot for emissions

There's a chicken/egg problem at work.

A carbon tax is most economists' favourite method of dealing with climate change. It is exactly the sort of simple, market-driven intervention that they tend to like: set a price per tonne of carbon emitted which is equal to the value of the damage that tonne does to the climate, and then sit back and what businesses and consumers react. Some may cut their usage; some may switch to low-carbon sources of energy, which suddenly become cheaper comparatively; and some may choose to just pay the extra cost (what happens in that last situation is debatable – some think the money should just count as general taxation, others that it should be put towards climate change prevention and mitigation).

The Washington Post's Brad Plumer suggests that it may not work as well as we would hope, however. He reports on a recent MIT study looking at the likely effect of a $20 a ton carbon tax in the real world – the value proposed by a pair of MIT researchers last month.

Plumer writes:

Sebastian Rausch and John M. Reilly of the MIT Global Change Institute recently put forward a proposal for a $20/ton carbon tax that would rise 4 percent each year, starting in 2013. (The funds would be used to offset taxes elsewhere.) Here’s what their economic model predicts would happen to U.S. greenhouse-gas emissions:

Blue line: MIT reference case with no carbon tax. Black line: EIA reference. Green line: Scenario with MIT carbon tax in place.

With a carbon tax in place, U.S. greenhouse gas emissions do start declining quite a bit (this is the green line). But by 2030, emission levels stall, even though the carbon tax keeps rising and rising each year. The United States wouldn’t get anywhere near the 80 percent cut by 2050 that the White House has envisioned.

One explanation here is that MIT’s proposed carbon tax just isn’t high enough. But Muro favors another possibility–that a carbon tax alone isn’t enough to drive deep reductions. The private sector tends to under-invest in energy R&D and key bits of infrastructure such as transmission lines. Without further policies, it’s unlikely that we’ll see a sweeping transformation of our energy system to give people alternatives to coal plants and gasoline-powered cars.

This echoes an argument I've heard several times from those on the more technical side of climate change prevention. For all that the economists and politicians like to talk about creating the conditions in which the private sector will be incentivised to help tackle climate change, those who are more keenly aware of the massive costs involved tend to be rather more pessimistic.

They point out that the carbon tax model provides a cash injection to providers of low-carbon energy – but only after the tax is already instituted. As a result, there's another weak link in the chain, which is the ability of those providers to secure loans to build the capacity required. That's possible for massive companies looking to get into a new area; and it's possible for smaller companies, provided they get enough certainty from the government to be able to convince bankers.

But the fear is that larger companies, already strongly embedded in the conventional energy infrastructure, have little incentive to devote money, which could be used to lower the cost of polluting fuels, to instead build new capacity; and smaller companies won't be left with enough time between when the government finally confirms a carbon tax, and when their new generation is actually needed.

At the same time, though, there is growing evidence that some companies really are going above and beyond the call of duty. Some of it may be greenwashing, and some may be token expenditure, but if there really is any sizeable investment in low-carbon infrastructure, then it makes a carbon tax that much more effective.

Carbon taxes can only lower emissions if they raise the price of polluting relative to an alternative. If that alternative isn't available, then they risk being simply another source of revenue for the state.

Wind turbines being prepared. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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The Telegraph’s bizarre list of 100 reasons to be happy about Brexit

“Old-fashioned light bulbs”, “crooked cucumbers”, and “new vocabulary”.

As the economy teeters on the verge of oblivion, and the Prime Minister grapples with steering the UK around a black hole of political turmoil, the Telegraph is making the best of a bad situation.

The paper has posted a video labelled “100 reasons to embrace Brexit”. Obviously the precise number is “zero”, but that didn’t stop it filling the blanks with some rather bizarre reasons, floating before the viewer to an inevitable Jerusalem soundtrack:

Cheap tennis balls

At last. Tennis balls are no longer reserved for the gilded eurocrat elite.

Keep paper licences

I can’t trust it unless I can get it wet so it disintegrates, or I can throw it in the bin by mistake, or lose it when I’m clearing out my filing cabinet. It’s only authentic that way.

New hangover cures

What?

Stronger vacuums

An end to the miserable years of desperately trying to hoover up dust by inhaling close to the carpet.

Old-fashioned light bulbs

I like my electricals filled with mercury and coated in lead paint, ideally.

No more EU elections

Because the democratic aspect of the European Union was something we never obsessed over in the run-up to the referendum.

End working time directive

At last, I don’t even have to go to the trouble of opting out of over-working! I will automatically be exploited!

Drop green targets

Most people don’t have time to worry about the future of our planet. Some don’t even know where their next tennis ball will come from.

No more wind farms

Renewable energy sources, infrastructure and investment – what a bore.

Blue passports

I like my personal identification how I like my rinse.

UK passport lane

Oh good, an unadulterated queue of British tourists. Just mind the vomit, beer spillage and flakes of sunburnt skin while you wait.

No fridge red tape

Free the fridge!

Pounds and ounces

Units of measurement are definitely top of voters’ priorities. Way above the economy, health service, and even a smidgen higher than equality of tennis ball access.

Straight bananas

Wait, what kind of bananas do Brexiteers want? Didn’t they want to protect bendy ones? Either way, this is as persistent a myth as the slapstick banana skin trope.

Crooked cucumbers

I don’t understand.

Small kiwi fruits

Fair enough. They were getting a bit above their station, weren’t they.

No EU flags in UK

They are a disgusting colour and design. An eyesore everywhere you look…in the uh zero places that fly them here.

Kent champagne

To celebrate Ukip cleaning up the east coast, right?

No olive oil bans

Finally, we can put our reliable, Mediterranean weather and multiple olive groves to proper use.

No clinical trials red tape

What is there to regulate?

No Turkey EU worries

True, we don’t have to worry. Because there is NO WAY AND NEVER WAS.

No kettle restrictions

Free the kettle! All kitchen appliances’ lives matter!

Less EU X-factor

What is this?

Ditto with BGT

I really don’t get this.

New vocabulary

Mainly racist slurs, right?

Keep our UN seat

Until that in/out UN referendum, of course.

No EU human rights laws

Yeah, got a bit fed up with my human rights tbh.

Herbal remedy boost

At last, a chance to be treated with medicine that doesn’t work.

Others will follow [picture of dominos]

Hooray! The economic collapse of countries surrounding us upon whose trade and labour we rely, one by one!

Better English team

Ah, because we can replace them with more qualified players under an Australian-style points-based system, you mean?

High-powered hairdryers

An end to the miserable years of desperately trying to dry my hair by yawning on it.

She would’ve wanted it [picture of Margaret Thatcher]

Well, I’m convinced.

I'm a mole, innit.