Guest Post by Geoff Russell. Geoff recently released the popular book “Greenjacked! The derailing of environmental action on climate change“.
Even if they don’t own one, most readers will have seen a Satnav, those miracles of modern technology which will direct you across town to a suburb and street you’ve never been to before. After you enter your destination, there’s a little pause and perhaps the screen displays a message like: “Calculating…”, and then the instructions start.
Okay, so why the pause?
Once it’s located its required satellites and knows where you are, the Satnav runs some form of shortest path algorithm to work out how to get to the destination. If you are interested, here’s a walk through of one popular algorithm in action.
Really impatient people might be annoyed by the pause. For such people, there’s a much faster way of proceeding which would make that pause so short as to be imperceptible. Here’s the algorithm for a no-pause Satnav. First make a list of each road passing through your current location. After all, you have to travel down one of these. Then consider some point a small distance (say 30 meters) away on each of the roads. It’s high school maths to determine if this point is closer to your destination than your current location. If it is, then off you go. Then at the next intersection of any kind, do the same thing again. The algorithm would be lightning fast, the pause would vanish, and it always takes you in the direction of the destination.
At this point you should get out a piece of paper and start doodling. Might the algorithm use dead end roads? Ah … yes. If you go down one, can you ever get out? Ah … no. Consider roads slightly less than tangential to a circle around your destination. Might the algorithm take them? Ah … I guess so. Could you end up driving backwards and forwards along such a road forever? Ah … yes, theoretically.
Obviously, the algorithm sucks; even though at each point it always chooses a road that takes you toward the destination. But it can suck even it doesn’t make any of the mistakes I mentioned. It can suck by simply taking a hopelessly circuitous route.
If you think about it, this algorithm is pretty close to the current international approach to tackling climate change. Of course, a Satnav is just for one person, but the climate change mitigation process is highly parallel, so it’s like everybody involved is using this same sucky algorithm.
How often have you seen news stories about some so-called climate friendly project; they all have a prominent claim somewhere like: “This project will deliver clean energy to Y thousand homes!” or, “This project will save X tonnes of CO2”? All such claims tell you is that the project is taking you somewhere closer to zero-carbon nirvana. They tell you nothing about whether you will ever get there or how long it might take.
Consider as an example: the on-going global roll out of biofuels.
Here’s the required claim about biofuels taking us nearer the destination; this particular version is from the US Department of Energy:
Life cycle analysis completed by the National Renewable Energy Laboratory, and later by Argonne National Laboratory, found that greenhouse gas emissions for 100% biodiesel (B100) could be more than 52% lower than those from petroleum diesel.
The past 14 years have seen biofuel crops spreading across millions of hectares of the planet with the result that in 2013 the global production of biofuels was 113 billion litres. That certainly sounds like a lot, but how much of the world’s transportation can it power? About 3 percent. So at the present rate of growth we could power most of the world’s transport in around 33 x 14 = 462 years.
So does biofuel fall into the hopelessly circuitous category of paths or the dead end category? First lets see what is required.
Defining climate goals
We can use the latest IPCC estimates to see what kind of ball park a decarbonisation solution needs to hit. I’ll round a lot of numbers to make it easier to understand. Accumulated greenhouse gas emissions during the industrial period were about 500 billion tonnes by the end of 2011 and rising at a rate of 50 billion tonnes per year. Our budget over the next 50 to 100 years to keep the planet from warming by less than 2 degrees is something like 1,000 billion tonnes. So we are half way there and we’ll get there by about 2020. At 50 billion tonnes per year we’ll hit 2000 billion tonnes by 2040 and the planet will warm between 2.6 and 4.8 degrees. This means we can continue at 50 billion tonnes for at most a decade but if we continue for 30 years, the best we can hope for is a 2.6 degree global average temperature rise or that the modelers got things really wrong; and in the right direction. But as many people are starting to appreciate, it isn’t the average temperature rise that is the worst part of global warming, it’s the reduced stability.
This way of defining the problem makes it clear that time spent on biofuels has been time wasted. A project which only gives a maximum savings of some 50 percent anyway in its target area and which will take decades to implement belongs in the bin. It’s like being on a leaking ship, issuing spoons to the crew to start bailing and initiating research into which kind of spoon gives the best result.
Hopelessly slow or a dead end?
But the biofuel roll out is worse than just too slow.
Despite this sub-glacial growth rate, some countries have hit what is called the “blend wall”. Most ethanol blends are 10 or 15 percent and the kinds of vehicles that can take higher blends are still not sold in sufficient quantity to move the amounts of ethanol being produced. In other words, at 3 percent we have a biofuel glut. Less than 3 million of the 15.8 million vehicles sold in the US in 2013 will take higher ethanol blends. The response to hitting the blend wall was a drop in consumption in some countries. Biofuel consumption dropped 10 percent in Germany and 58 percent in Spain.
But even if there was no blend wall and even if we had 33 times more biofuels, we’d still have problems because they aren’t displacing an amount of carbon emissions equivalent to the fossil fuels they are replacing.
The Edgar 2014 Trends in Global CO2 Emissions report estimated that the 3 percent biofuel production didn’t displace 3 percent of fossil fuel transportation emissions, but more like 1 to 2 percent. This is consistent with the US Department of Energy estimate above. The reasons are complex and numerous but let’s just list a few: increased deforestation, particularly over peat soils in Indonesia, nitrous oxide emissions from fertilised fields. Nitrous oxide has 300 times the impact of CO2 on warming, so it doesn’t take too much to undermine emission reductions obtained by replacing fossil oil.
To entirely replace oil we’d need to scale up biofuels by 33 times and solve the nitrous oxide, deforestation and other problems. We’d also have to do it quickly. Is this possible?
The answer is clearly no.
Leaving aside Brazil’s fairly long history with biofuel, it’s taken 14 years to hit the paltry 3 percent figure and that’s happened without an equivalent drop in emissions. Also obvious is that this decade or so of biofuel growth has been as easy as it gets, largely just persuading farmers to switch from growing feed for livestock or food for people to growing fuel for cars by distributing buckets of money. Achieving the other 97 percent will be far harder.
Besides which, we don’t have the land.
Looking at the table above and doing a little arithmetic, we know how much land it will take to get 33 times the current output. At 7200 litres per hectare, we’d need half a billion hectares. At 1700 litres per hectare we’d need over 2.1 billion hectares.
So biofuels are a circuitously slow route to a decarbonisation cull-de-sac. We’ve wasted a decade on them and rather a lot of money. There may not be a perfect pathway, but we should at least stop rushing off on tangents with enormous vigor pursuing strategies which achieve less than bugger all. It’s time we acted more like real satnavs and started to plan.