The rate of loss of primary forest as last measured between 2000-2005 was 6 million hectares. That's equivalent to 60,000 km2, an area the size of Ireland. And this is only for primary forest, that is ancient rainforest.
Stating that the rainforest is permanently lost in this case however is incorrect. The forest is not necessarily being clearcut or converted to other land use, it is reclassified from primary to modified natural rainforest due to the fact the forest have been subject to logging or another disturbance. (This is according to the Forest Assessment and Reporting Service)
The actual global deforestation rate is estimated at 13 million ha. per year.
The total forest cover is 4 billion ha. It is estimated that 1% of that, an area equal to 40 million ha is burnt down each year. This area is equal to 6.5 times the area of deforested primary forest and 3 times the area of total deforested area each year.
It has been estimated by the IPCC that deforestation accounts for 17-20% of global carbon dioxide emissions.
ON FOREST FIRES
It seems to me that whilst all the publicity is on deforestation, very little publicity goes into forest fires mitigation. When I was a boy, the mountain next to where I lived was set alight. Hundreds of thousands of trees burned. The fire was spectacular. 20 years later and the forest is managed appropriately: it has been reforested, the land is grazed by feedstock and large strips of grassland divide the forest so that if it is set alight again, the fire's progress will be put in check when it reaches the grassland border. Forest fires really are a vitally important area of forest management we need to focus on because when a forest burns, we don't just lose a carbon sink, the carbon stored in the forest over decades of growth is released into the atmosphere all at once.
We are lucky in that respect that most of the forest fires occur in developed countries where we have enough money to protect our forests. The main forest fires I have heard of over the past few years were in California, Australia, Portugal, France and Spain. Most of the fires occurred in countries that are particularly dry in summer and occasionally windy. If the forest located in these areas were managed properly, a vitally important carbon sink would be preserved.
ON PROTECTING THE PRIMARY FOREST
Primary forest is located mainly in the tropics. Deforestation for logging is one of the causes of deforestation but another more important reason is natural resource extraction which is also very polluting.
One way to stop deforestation is to ensure the forest is worth more standing up than logged. By giving money to locals to protect the rainforest instead of selling their land, it is possible to avoid a substantial amount of logging. For larger scale projects, the idea has the potential to be extended to paying governments from developing countries but there is a lot of potential for corruption in that respect and for the money to go astray.
One of the charities trying to encourage the protection of the rainforest by ensuring it is worth more standing up than logged is Cool Earth. Based on the costings provided by Cool Earth to protect an acre of rainforest, the annual cost of protecting the rainforest could be between £891 million and £1.5 billion. Of course, this is a purely theoretical figure, there's only so much mileage in the work they can do.
If we take into account the fact that to protect the rainforest, the main job involves protecting the border most vulnerable to deforestation rather than the whole area at risk of deforestation, the cost could be considerably less. It may well be that the true cost is £445 to £750 million, it depends on whether deforestation only occurs at the borders of the forest or if areas deforested cut deeper into the forest.