H for 'human': The missing climate link?
As many commentators have pointed out down the years, virtually all the hopes expressed by governments in terms of reducing carbon emissions ultimately hang on technology.
It stems from the famous IPAT equation:
Impact = Population x Affluence x Technology
...sometimes expressed as...
Impact = Population x GDP/capita x Impact/GDP
The Chinese government has talked about its one-child-per-family policy as being its historical contribution to curbing emissions (somewhat disingenuously, given that climate concern wasn't the reason for adopting it) - but it's just about alone on that.
In fact, virtually no government intends to restrict the P in the equation, and certainly none wants to curb the A.
Which puts the load squarely on T.
What this translates to, then, is doing everything we do now and more - but with less energy.
It means using energy more efficiently, and adopting technologies that produce far smaller amounts of CO2 for each unit of energy.
The equation is often used for the energy input side of things - but what about when we apply it to consumption?
Is it entirely reasonable here to break things down into these components, or is it more complex than that?
And if it is that simple, can T on its own produce enough change?
In the European Union, when you go to buy a refrigerator, it'll be labelled with a letter indicating how efficient it is with energy - which consumers may look at if they're interested either in saving money or saving emissions.
In 2006, the UK's Sustainable Consumption Roundtable concluded:
"Market share of A-rated models increased from 1% to 76% in five
years to 2005. The least efficient new fridge freezer on sale today consumes only half as much energy as the least efficient products on the market eight years ago.
"However, demand for second fridges has risen so that total energy
consumption only reduced by 2.2% over the same period."
In other words, the policy worked, to the extent that consumers chose more efficient products and manufacturers responded by making their ranges leaner and greener.
But we also bought more fridges - negating the technological advance with changing behaviour, presumably related partly to increasing affluence, and perhaps partly from the psychology that says "I'm saving on this, so I can spend more on that".
Couched in the terms of the IPAT equation, you could say that T reduced, but A increased commensurately - though I'm not sure that does it justice.
Now, in the Journal of Industrial Ecology, Eric Williams and Liqiu Deng from Arizona State University have gone through the short but intense history of microprocessors, looking to see whether IPAT works there, and at what effect behavioural changes might have had in our use of them - and, therefore, our use of energy as it relates to computers.
Chips have become much faster, of course, over the last 12 years - inside a typical home PC, by a factor of 10, the researchers suggest.
And the amount of electrical energy needed per calculation has shrunk markedly.
However, they conclude...
"... energy use per typical microprocessor is roughly constant over the 12-year period.
"The explanation of this result is that although technological progress dramatically reduces the energy needed per transistor, it also induces demand for more powerful chips..."
The case is remarkably similar to 'fridges. The energy cost per unit of refrigeration - shall we call that unit something conventional like a litre, or go for something more visceral such as a pie, a rasher or a tinny? - reduces, but we just refrigerate more of them.
A similar pattern cited by Deng and Williams concerns cars in the US.
Fuel efficiency increased markedly over automotive history, at least until the 1990s. But the distances people travel and more recently the size of vehicles have changed in the opposite direction. As a result:
"There was a net increase of fuel use from 391 gallons per person in 1970 to 453 gallons in 2006."
And environmentally, that's what's important.
The two academics suggest a different equation comes into use, which I guess would garner the acronym PIFI:
Product Impact = Functionality demanded of typical product × Impact/functionality
It's not, perhaps, a straightforward concept.
Who is "demanding" functionality, for example, is an intriguing question. Were there gangs on the streets demanding television, or SMS text messaging, before they happened?
I think not; yet now they're here, they're things societies wouldn't willingly give up.
Where this leaves attempts to curb emissions isn't clear.
But if T for technology is the crucial issue, it suggests we'd better understand more about drivers of use - what we're likely to adopt, what we're likely to demand and how industries will adapt to new challenges - because how H for humans use the stuff is perhaps going to be as important as the technologies themselves.