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.

Show Hide image

A swimming pool and a bleeding toe put my medical competency in doubt

Doctors are used to contending with Google. Sometimes the search engine wins. 

The brutal heatwave affecting southern Europe this summer has become known among locals as “Lucifer”. Having just returned from Italy, I fully understand the nickname. An early excursion caused the beginnings of sunstroke, so we abandoned plans to explore the cultural heritage of the Amalfi region and strayed no further than five metres from the hotel pool for the rest of the week.

The children were delighted, particularly my 12-year-old stepdaughter, Gracie, who proceeded to spend hours at a time playing in the water. Towelling herself after one long session, she noticed something odd.

“What’s happened there?” she asked, holding her foot aloft in front of my face.

I inspected the proffered appendage: on the underside of her big toe was an oblong area of glistening red flesh that looked like a chunk of raw steak.

“Did you injure it?”

She shook her head. “It doesn’t hurt at all.”

I shrugged and said she must have grazed it. She wasn’t convinced, pointing out that she would remember if she had done that. She has great faith in plasters, though, and once it was dressed she forgot all about it. I dismissed it, too, assuming it was one of those things.

By the end of the next day, the pulp on the underside of all of her toes looked the same. As the doctor in the family, I felt under some pressure to come up with an explanation. I made up something about burns from the hot paving slabs around the pool. Gracie didn’t say as much, but her look suggested a dawning scepticism over my claims to hold a medical degree.

The next day, Gracie and her new-found holiday playmate, Eve, abruptly terminated a marathon piggy-in-the-middle session in the pool with Eve’s dad. “Our feet are bleeding,” they announced, somewhat incredulously. Sure enough, bright-red blood was flowing, apparently painlessly, from the bottoms of their big toes.

Doctors are used to contending with Google. Often, what patients discover on the internet causes them undue alarm, and our role is to provide context and reassurance. But not infrequently, people come across information that outstrips our knowledge. On my return from our room with fresh supplies of plasters, my wife looked up from her sun lounger with an air of quiet amusement.

“It’s called ‘pool toe’,” she said, handing me her iPhone. The page she had tracked down described the girls’ situation exactly: friction burns, most commonly seen in children, caused by repetitive hopping about on the abrasive floors of swimming pools. Doctors practising in hot countries must see it all the time. I doubt it presents often to British GPs.

I remained puzzled about the lack of pain. The injuries looked bad, but neither Gracie nor Eve was particularly bothered. Here the internet drew a blank, but I suspect it has to do with the “pruning” of our skin that we’re all familiar with after a soak in the bath. This only occurs over the pulps of our fingers and toes. It was once thought to be caused by water diffusing into skin cells, making them swell, but the truth is far more fascinating.

The wrinkling is an active process, triggered by immersion, in which the blood supply to the pulp regions is switched off, causing the skin there to shrink and pucker. This creates the biological equivalent of tyre treads on our fingers and toes and markedly improves our grip – of great evolutionary advantage when grasping slippery fish in a river, or if trying to maintain balance on slick wet rocks.

The flip side of this is much greater friction, leading to abrasion of the skin through repeated micro-trauma. And the lack of blood flow causes nerves to shut down, depriving us of the pain that would otherwise alert us to the ongoing tissue damage. An adaptation that helped our ancestors hunt in rivers proves considerably less use on a modern summer holiday.

I may not have seen much of the local heritage, but the trip to Italy taught me something new all the same. 

This article first appeared in the 17 August 2017 issue of the New Statesman, Trump goes nuclear