Tuesday, March 3, 2009

An alternate look at tackling climate change

In today's Independent, Simon Usborne has published an article entitled "Inconvenient truths: Don't believe the greenwash", in which he makes some rather odd claims about what needs to be done to tackle climate change effectively. I have to admit some of them sound plausible, but I'm uncomfortable with them as well, and I'm not convinced on a lot of them. For instance:

Cute animals will have to die

You may not have come across the Bewick's swan. The smallest swan found in Britain, it reaches our shores from its Siberian breeding grounds in October and, along with 65,000 other water birds, it splashes down in the wetlands of the Severn Estuary. It is, without doubt, very cute.

But soon, it will have to find somewhere else to feed. In a few years' time, hundreds of lorries and cranes are set to sling 10 miles of steel and concrete across the most beautiful and ecologically diverse of estuaries, flooding the swans' habitat. Could anything be more of an affront to the eco-minded? The call would seem to be as clear as they come: save the swans, say no to construction.

But it isn't that simple. All that steel and concrete will become the Severn Barrage which, by harnessing the tides, would provide 5 per cent of Britain's electricity, with no nasty carbon emissions. So, which to choose: clean electricity, or the protection of birds and beasts?

Now there are situations where this might actually apply. Maybe this is one; Bewick's Swan is relatively common worldwide, though I'd like to know more about its range in the UK before passing judgment. If a distinct subspecies was endemic to a small area, it would be very hard to justify building the plant if there were any reasonable alternative (like, I dunno, how many wind turbines could you make with the money that will be spent there?)

To be fair, Usborne doesn't pass final judgment on this particular case either, but it's inevitable that many other hard choices like that will arise in the future. We have them now; consider Manitoba Hydro's own Wuskwatim Generation Project. If we want the midwestern US to stop burning so much coal, we have to be prepared to provide them with an alternative. And note that hydro dams are also vital energy storage devices, vital for really effective use of solar and wind power. (When the wind is blowing and/or the sun is shining, you can reduce the flow through the turbines and allow more head to build up behind the dam, which can be tapped later when needed). Yet it can't be denied that it will have impacts on local ecosystems, not to mention some people's livelihoods.
We need nuclear power

"The whole universe runs on nuclear energy, so why not us?" argues the environmental scientist James Lovelock. While there are associated concerns about weapons and radioactive waste, a government White Paper published last January found that nuclear power emits only 2 to 6 per cent of carbon per kilowatt-hour of that emitted by the cleanest fossil fuel, natural gas. And it factored in everything from the uranium mining through to power-plant decommissioning.

About 18 per cent of the UK's electricity is currently generated by nuclear power, with all but one of our existing plants scheduled for decommissioning before 2023. We need to build more now because, however much we'd like it to, wind power cannot be relied on to generate enough electricity at the times when it is needed. As John Constable, the director of policy and research at the Renewable Energy Foundation, said in December: "To generate 30 or 40 per cent of our electrical energy from wind power would present unmanageable and unaffordable difficulties at the present."

Even Sweden has just announced plans to overturn a 29-year ban on atomic plants. "I'm doing this for the sake of my children and grandchildren," said Center party leader Maud Olofsson.

This may actually be true in some cases. In some parts of the world there may not be enough hydroelectric capacity to stabilize the grid as mentioned above, though I still wonder if something like flywheel energy storage couldn't be rolled out pretty quickly (certainly as fast as wind turbines themselves). But if not, nuclear energy might be the best of a bad lot. I certainly don't think there's any place for it in Manitoba, despite what some small-town mayor might think.

Moving on:

Counting food miles will get you nowhere

It's true that our suppers have never travelled so far to reach our plates – asparagus from Peru, green beans from Kenya, lamb from New Zealand. Importing bananas and kiwis is one thing (they don't grow so well in Kent) – but surely it's madness to fill our supermarket aisles with butter, apples and beans from the other side of the world?

Well, not necessarily. The food miles argument is perhaps one of the most criminally oversimplified in the whole green debate.

First, it's worth looking at just how much food we do import. According to the Department for Environment and Food's latest figures, we are 61 per cent self-sufficient; crucially, when it comes to foods we can produce here, that figure rises to 74 per cent.

But what of the relatively small percentage of food we do ship in? The food miles argument would have it that a leg of lamb's carbon hoofprint is in proportion to the number of miles it travels. But that ignores the concept of scale. Say a small local farm produces 10 tons of lamb, and has a lorry that can carry one ton at a time. And say it is 100 miles from the nearest market. You get lamb with 100 food miles, but the farmers have to make 10 trips to transport their meat.

Meanwhile, lamb from a bigger farm 500 miles away would travel 500 food miles, but they've got a 10-ton lorry so they do it in one trip. Sure, the big truck guzzles more gas than the little one, but not five times as much, so the carbon footprint of the far-flung lamb is smaller.

This example is hypothetical, but apparently there are some real-world examples that support this:
OK, that's a fictional example. But there have been more rigorous studies. Adrian Williams, an agricultural researcher at Cranfield University, has called the food miles argument "foolish: provincial, damaging and simplistic". Williams and his team have looked at the relative carbon footprints of produce grown locally and thousands of miles away, taking into account factors such as fertilisation, irrigation, means of transportation and harvesting methods – not just the number of miles from field to fork.

Williams showed that apples from New Zealand may be "greener" than those grown locally because the climate there allows for much greater yields, and farms rely mostly on electricity generated by renewable sources. A study at New Zealand's Lincoln University showed that lamb shipped to Britain produced one-quarter of the CO2 emissions of British lamb when you accounted for the relative reliance on fertiliser and energy-hungry irrigation systems, as well as the method of transport – shipping emissions have been shown to be about one-60th of those produced by air travel.

Now this is indeed interesting, though I have to wonder; if the UK does adopt enough alternative energy sources to drastically reduce their coal consumption (and they bloody well have to), how much of this will still apply? The reduced reliance on fertilizer might still make a difference, I dunno. It would help if they had absolute figures rather than merely relative ones. It would also help if I knew more about agriculture than I do.

An old banger beats a hybrid

Driving a banger might well be greener than zipping about in a hybrid car such as the Toyota Prius. The zeal with which green-minded drivers have embraced the Prius is scarcely credible, because the hybrid's eco-credentials are far from clear. Since its 1997 launch, the Prius, which combines a battery with a petrol engine, has become a big seller – Toyota has shifted a million of the things, and drivers include a clutch of celebrities led by Leonardo DiCaprio – and a symbol of everything a standard car is not: green, clean, virtuous.

But is it? Petrolheads have questioned Toyota's claims. Not always successfully; in 2007, an American market research company pitched too high when it published a report claiming that the Humvee, thought to be the worst-offending car on the road, had a smaller carbon footprint than a Prius. Further studies discredited that, but the researchers were on to something. Because the Prius uses a big battery to complement its engine, a Prius is green when it gets to the road, managing (Toyota says) a respectable 65.7mpg in mixed driving. But that hulk of a battery includes almost 14kg of nickel – and the Prius, therefore, requires more energy to build than a standard car of a similar size.

And some road tests have questioned whether it's even that green on the road. Drivers claim their dashboard gauges rarely show the promised 65.7mpg. In one test, the motoring journalist Jason Dawe took part in an experiment in which a Prius and a BMW 520 diesel were driven 545 miles from London to Geneva, including 100 miles of urban driving. The Prius guzzled 11.34 gallons of fuel (48.1mpg) compared to the BMW's 10.84 gallons (50.3mpg). Yet the Prius owner would pay £15 in road tax (£115 for BMW), be exempt from the London congestion charge (£8 a pop) and get to feel smug.

There is indeed something to this. Certainly for someone like me, who doesn't drive that often, scrapping my VW to buy a Prius would be highly counterproductive. On the other hand, if you drive a lot, especially in the city, a hybrid might be the best choice (there's a reason the taxi companies are snapping them up as fast as they can). On the highway, not so much; a good diesel is better than most hybrids. My dad's Jetta TDI got 60 mi/gal (Imperial), which is 4.7 L/100 km, or 50 mi/gal (US), on a trip of around 2100 km. You'd be hard pressed to do that in a Prius.

Coal is not a dirty word

The coal-fired power station is the ultimate symbol of the way we send clouds of carbon into the atmosphere – yet the latest wisdom is that we should build more coal-fired power stations.

Why? Solar, wind and tidal power will only get us so much electricity. The other part of the solution may well involve a dirty, black rock we might have thought had been cast into history. Coal is seen as a key part of Britain's formula for green energy. Ed Miliband, Secretary of State for the Department for Energy and Climate Change, recently said the black stuff "has to be part of the energy mix, partly because there is an abundant source in Britain". Britain still has enough coal to power the country for a century – and, in the longer term, "clean coal" is seen as a viable if imperfect way for developing countries to green up their power.

But how can coal be clean? The answer lies in a technique called carbon capture and storage (CCS). Traditionally, coal power plants belch tons of CO2 straight into the atmosphere. CCS power stations, or those fitted with the technology, would capture the greenhouse gas and bury it, usually in depleted oil or gas fields in, say, the North Sea. The Intergovernmental Panel on Climate Change estimates that a modern power plant with CCS could reduce CO2 emissions by 80 to 90 per cent compared to a standard plant.

The first pilot CCS plant began operation in Germany last year. The Schwarze Pumpe processing plant separates and squashes its CO2 emissions to one-500th of original volume before pumping the gas into cylinders for transport and burial 1,000 metres underground in a gas field. In the next few weeks, the German energy company E.ON is expected to get approval to build a plant at Kingsnorth, in Kent.

The prospect of Britain's first new coal-fired power station for 30 years horrifies green campaigners, and Kingsnorth has seen clashes between police and protesters who say CCS is expensive, requires huge amounts of energy itself and won't greatly cut emissions for decades. But "clean" coal has momentum.

This one I have a hard time accepting. Given that nobody has yet been able to demonstrate that widespread CCS is even feasible, we should be looking at conservation, solar, wind, and even nuclear before we even consider adding coal capacity.

Organic farming doesn't add up

Organic must be good, right? Better food, free from nasty pesticides, packaged in recycled cardboard (preferably brown), with a bit of soil thrown in to confirm its wholesome provenance; better for us, better for the cows and chickens and lambs and fruit and veg, better for the planet.

Or have we been fooled by the virtuous glow of organic brands? There's a reason a kilo of organic carrots at the online supermarket Ocado costs £1.49 while a bag of standard carrots the same size costs 95p. Organic food is more expensive to farm. That's because, per acre, the yield is usually lower than for standard crops because organic fertilisers aren't as effective. And smaller farms are often less efficient in harvesting, processing, transporting and associated carbon emissions (see food miles).

Organically reared livestock provide less meat per acre, and their impact is greater than that of vegetables. According to the Department for Environment and Food, 75 per cent of the greenhouse gas methane on farms is emitted directly by ruminants – cattle and sheep. But feed for organic animals is higher in roughage and low in concentrates, resulting in higher methane output per beast. A study by Dr Andy Thorpe at the University of Portsmouth suggested that 200 cows emit the annual equivalent methane to a family car driven 111,850 miles.

The big problem I have with this is that it focuses primarily on organic meat, and it's pretty doubtful that farmed meat of any sort, organic or otherwise, is a good move as regards carbon emissions. But more on this later.

Ancient forests must be axed

It isn't picturesque – but it is practical. It sounds ruthless, but wheezy old trees can't suck up the carbon like they used to. A tree absorbs roughly 1,500 tonnes of CO2 until it reaches 55 years of age, after which absorption slows. And when that tree decomposes, it belches all the CO2 back out again. So although the results won't be terribly scenic, if we were utterly rational, our trees should get the axe after reaching their CO2-hoovering peak. The wood can then be used to make furniture, houses and many of the products we currently manufacture from less sustainable materials. We should then plant fresh seedlings to farm.

Again, there's a ring of plausibility to this, but it overlooks a very important point. Sure, older forests don't absorb as much CO2, but they may still absorb more than newly planted tree farms will for a few decades. I'm not 100% sure, but I think that a disproportionate amount of the 1500 tonnes cited above comes later in that 55 year period -- and we need to be absorbing the stuff now. So unless a forest has reached a point where it is releasing more CO2 than it consumes, better to plant over an existing clearcut, perhaps with some selective logging of some older growth.

Not to mention, the slogan "a tree farm is not a forest" has a lot of truth to it. A replanted forest does not have the biodiversity of an old growth forest, and ecosystems that are less diverse are usually less stable, i.e. more vulnerable to sudden events like a severe pest or disease outbreak, which could throw a big monkey wrench into the carbon absorption scheme.

On the other hand, if a forest has died (like large areas of BC's forests have) then it might be better to clearcut those areas as much as possible, before the trees decay.

Nature needs GM crops

The public image of genetically modified foods lies somewhere between that of asbestos and nuclear weapons. Think GM and many of us picture tomatoes being cloned in laboratories with nasty strip lights and bubbling test tubes, or campaigners in white suits tearing up "frankencrops" in fields of undisclosed location.

But for many of those pondering the future of food, GM doesn't evoke such horrors – it's the answer to a potential global crisis taking root in fields from Bedfordshire to Brazil. The price of feeding a global population of more than six billion is its huge environmental impact.

According to the latest report from the Intergovernmental Panel on Climate Change, agriculture – with all its chugging tractors, fertiliser production and farting cows – accounts for 14 per cent of greenhouse gas emissions, throwing out tonnes of carbon dioxide, nitrous oxide and methane. That's more than the world's cars, trucks, trains, ships and planes put together. In fact, UN figures suggest meat production alone churns out more greenhouse gases than transport.

An easy solution would be to reduce the posterior emissions of ruminants by eating less beef, but before we all go semi-veggie, perhaps we should give bioengineers, and their genetically modified carrots, a second chance. One third of agriculture's greenhouse emissions are caused by the production of nitrogen-based fertilisers. Some of the biggest names in GM are developing crops whose greater efficiency would mean higher yields for less fertiliser.

The thing is, reducing our meat intake is likely to have much more effect on our carbon footprint than they're likely to achieve with GM crops in the near future. And the near future is what we're talking about. Further down the line, when we have a better idea of what we're doing, there might indeed be a legitimate role for GM crops, but I don't think we should be relying on them right now.

Carbon offsetting doesn't pay

Dreamed up by politicians and businessmen rather than climate change scientists, carbon offsetting has been described by Friends of the Earth as "a smokescreen to avoid real measures to tackle climate change". In the same way as the medieval church allowed monied folk to buy their way out of sin, so offsetting is designed to allow the wealthy to salve their consciences for all those shopping trips to Dubai. It would be far greener not to "spend" the carbon in the first place. And that's without going into the impossibility of accurately calculating how much carbon is emitted on any given flight and ensuring the "offset" doesn't involve planting a tree that will end up emitting even more carbon.

Usborne is far from the first person to point this out; on the other hand, depending on how the offset money is spent it might be an unfair comment. Probably not all offset agencies are created equal, though.

China might be the solution

We've all seen "Made in China" stamped on disposable goods – but you're now likely to find the same stamp on solar panels, wind turbines and the rechargeable batteries used by electric vehicles. According to a Climate Group report, China is on the way to overtaking developed countries in creating clean technologies. The world's largest emitter already leads the world in terms of installed renewable capacity. With its own coastal cities threatened by flooding, and soaring world demand for its green technology, China is on the way to becoming a "low-carbon dragon economy".

More plausible than a lot of the propaganda would have us believe, though I'm not sure if the alternative energy technologies they produce are enough to make up for the coal they burn. But maybe they are working on phasing out coal; again, I don't know enough to say. One thing that's clear, though; a certain former boss of mine would hate to be told this, which gives it some appeal for me.

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