One of the great truisms of the fight against climate change is that we cannot hope to avoid a future as the new republic of Great Atlantis without tackling the problem of tropical deforestation.

In many ways, addressing deforestation should be the easiest part of the battle. According to the UN it accounts for 20 per cent of manmade carbon emissions each year with roughly 50,000 square miles of tropical forests disappearing every 12 months - equivalent to half the land mass of Great Britain.

But while the problem is huge study after study has shown that halting deforestation would represent the most cost effective means of reducing emissions. According to a study from UK think tank The Policy Exchange this week, investing the £550m the government is spending on biofuel subsidies alone in forestry protection would increase avoided emissions 50-fold.

In short, no carbon reduction initiative or renewable energy project offers better value for money than forestry protection. It seems so simple: develop a workable means of forestry protection and we can slash emissions by 20 per cent in double quick time, giving economies the extra breathing space they require to make the journey towards low carbon technologies.

The problem - and it is a dilemma that has haunted environmentalists since long before Sting began patronising Amazonian tribes - is how to achieve this, and once again the politicians appear to be looking in all the wrong places.

The deforestation debate at the latest round of UN climate change talks in Ghana this week centred on a number of different proposals, all of which aim to throw cash at the problem.

A tax on forestry firms to fund forest protection is one idea in the mix, as is a huge increase in forestry investment funds, such as those recently proposed by the Brazilian government. But the idea that appears to have gained the most traction and now seems likely to be adopted is the integration of forestry schemes into the global carbon market.

The thinking behind such a move is simple: provide countries with a way of monetising the continued survival of their tropical forests through the sale of carbon credits and they have a clear incentive to protect them and not cut them down.

But even if you ignore the potential dampening effect on the price of carbon that is likely to result from the issuing of millions of new carbon credits, you have to ask if such an approach could work?

The US delegation has previously voiced concern that such a scheme would effectively equate to paying loggers and the governments that fail to act against them not to do something that is already illegal. It is easy to dismiss this as the classic obstructionism that has come to define the US approach to climate change talks - but on this occasion they have a point.

Paying people not to do something smacks of a protection racket, and the problem with protection rackets is they have a habit of getting nasty.

The belief that if you throw enough cash at forestry protection you can halt the destruction of our remaining forests conveniently ignores quite how huge tropical rainforests still are.

There was a lovely story this week revealing that nearly half of Australia remains completely untouched by man with three million square kilometres qualifying as genuine wilderness. Well, the Amazon Rainforest stands at around 5.5m square kilometres - it's getting smaller all the time, but like the great forests of Africa and South East Asia it is still gargantuan.

Forestry protection initiatives have been very successful on a relatively small scale, but you can't just throw a fence round these forests and keep the loggers out. Nor can you pay them off and hope that they will stick to their side of the bargain and stop logging when there are such vast swathes of land for them to abuse.

Moreover, several green groups have voiced concerns that monetising the forests could have dire consequences for indigenous communities. If governments recognise the forests that make up their homes as a financial resource the temptation to force them off their land would be huge.

Alternatively, the money raised from forestry credits could go direct to the communities that call those forests home. But, while you can debate the moral issues surrounding the historical payment of reparations to indigenous communities, many of whom have been horribly abused over the centuries, there are few who would argue that a massive influx of cash can bring with it huge social problems as well as benefits.

None of this is to say that investment in forestry protection should not be increased, nor that it is still one of the most cost effective means of curbing emissions. But politicians need to recognise the limitations of such an approach.

In many ways forestry protection is a classic case of treating the symptom and not the cause.

The real answer to the forestry crisis lies not in carbon credits, investment funds, or anti-logging enforcement squads; it lies in the underlying economics that drive deforestation.

It is this that should have dominated the agenda in Ghana and should underpin those parts of the post-Kyoto deal that address deforestation.

We cannot hope to address deforestation while demand for timber and agricultural land makes illegal and unsustainable logging so attractive. If government's are really serious about the problem far more needs to be done to address these issues by enhancing productivity on existing agricultural land, curbing demand for biofuel crops that only serve to fuel deforestation, and developing alternatives to timber.

Get that right and then forestry credits might just stand a chance of working.

Right, I'm off to try and develop me some thin film solar cells, there's a lot of money in it apparently.

Have a good weekend,

Cheers,

James