I've handed the reins of my blog over to Mark Avery for most of June. Mark's sharing the successes and challenges of saving nature around the world in the run up to the Rio+20 Earth Summit.

I think I’m pretty good at recycling compared with the people who live in my street. I used to glance left and right as I put out the rubbish and recycling separately and pride myself that I had so much to recycle and so little rubbish (and then worry a bit about all those wine bottles on display). Now we have bins, I can’t tell how we are all doing. Almost certainly, my street has not caught up with the average Swiss street which recycles about half of all domestic waste.

Burning fossil fuels taps into the energy stored in plants and animals that were alive millions of years ago – that’s what coal and oil are. Wouldn’t it be better to use plants growing now, get the energy from them, re-grow the crops, re-trap the carbon dioxide and simply recycle the carbon round and around and around? Fuel recycling, or biofuels?

It is a good idea in many ways, but it just doesn’t work out well in practice. Growing crops for fuel uses lots of energy in manufacturing fertilisers and pesticides, then there is the vehicle use in planting harvesting and transporting crops and there are other inefficiencies in the system.  Probably more important though, is that the fertilisers we use are a potent source of nitrous oxide – a more powerful greenhouse gas than carbon dioxide and when that is taken into account then biofuels don’t do very well at all.

However, it gets worse. Growing biofuel crops takes lots of land – just like growing crops for food. We hear that we must grow more food to feed the world, and although that is a somewhat simplistic view (see article of 10 June) biofuels and food production compete for land and too much biofuel production will increase food prices.

However (again), it gets worse still. On a crowded planet with little spare productive land, the temptation is to go and chop down some forest and plant either food or biofuels on that land ignoring the shared ecosystems service that those forests provided (see article of 7 June).

If a farmer, whether he (or she) be in Iowa or Ipswich, grows fuel instead of food the world doesn’t say ‘I’ll go for a drive instead of eating’, it still demands its meal. Food and fuel are global commodities so that farmer’s action may persuade someone in Indonesia to cut down some more rainforest. And rainforests are such great carbon stores that the maths show that you only need tiny increases in rainforest destruction to wipe out any carbon savings from biofuels, and indeed to put yourself in carbon debt. In the worst case, if you chop down a rainforest to grow biofuels you may make money, but you don’t recoup the lost carbon for about 80 years.

But governments fell for the allure of biofuels and now, every time you fill up your car with fuel in the UK, that fuel has a splash of biofuel in it, and that biofuel will, whether it was grown just down the road or on the other side of the world, have hastened the destruction of rainforests and the wildlife that they support. And it won’t have reduced your carbon footprint very much, or maybe even at all.

Remember that when you fill up, you really may be putting a tiger in your tank, and in Brazil the boom in bioethanol production threatens the wildlife, carbon stores and productivity of the Cerrado.

There is another way you can step up for nature - are you a member of the RSPB? We're helping wildlife in so many ways, across the UK and beyond. Your support is crucial. Without our members we couldn't do all of this vital work for nature. Click through to learn more about becoming a member of the RSPB.

Dr Mark Avery is a former Conservation Director of the RSPB and now is a writer on environmental matters. We’ve asked Mark to write these 20 essays on the run up to the Rio+20 conference.  His views are not necessarily those of the RSPB.  Mark writes a daily blog about UK nature conservation issues.

  • Hi Mark; my Liberal MP Stephen William does not seem to have signed up either which is profoundly disappointing result when so many of his past "indications"on his web site would seem to display otherwise................

  • peter - our energy intense lifestyles are indeed 'the' problem.  I too have cut down on my meat consumption and am vegetarian four days a week - it really wasn't much of a pain to do. As with food, there is a lot of energy waste and that's a good place to start - cut out waste! And then there are things that we can all do with little inconvenience and no pain to cut emissions further.  But (although I have solar panels on my roof) I can't decide energy production policy on my own - that is what we have governments to do.  So a bit of green lobbying too is a good idea.  I have just reminded my MP that although she replied to my email in quite an intelligent way she has not yet signed up to the Stop Climate Chaos Rio Declaration...I wonder whether she will?

  • The problem is our energy intense lifestyles. Until we cut down significantly on these we are in a very poor position to lecture others from the UK. I note that the "cerrado" that you feature is a beef growing area. I have significantly cut down my meat consumption and now largely eat chicken only.

    Will someone somewhere set up a moral argument defending the tax havens as the Euro implodes? Why is this creaming off of the wealth in trillions by billionaires, dictators, mafias not subject to the rigour of analysis "sustainability" at Rio plus 20?

  • redkite - thanks for your comment.  It really does irritate me that there is no choice on this subject - when public policy gets things wrong it gets things wrong big-time.

  • Good blog again Mark, the conclusion one draws, is of the madness of cutting down our natural vegetation, including the earth's forests, to grow biofuels, with great use of energy and chemicals, when the earth's natural vegetation especially the forests is already largely doing the job for us and without the need for large inputs of chemicals and energy.

    The media and our politicians are all currently wringing their hands at our current economic problems (and to a limited degree possibly justifiably) but one consequence of the these problems is the current fall in the price of crude oil to below $100/per barrel. This is important because it renders the madness of biofuels even less economic on top of being logically "nutty".