Raw timber and wood-processing industries account for 70% of Finland's total exports. Still in 1993, Finland's forests in 1993 produce some 30 million cubic metres of wood more than industry can process. Experts fear that if the consumption of wood continues to decline, the country's healthy forests may degenerate into tangled thickets. The current surplus situation is the result of improved management and harvesting practices of the largely natural forests, and the increasing value of timber as a resource. However, the forests are now in danger of aging beyond the optimal point, meaning that the growth rate will eventually decline. Unthinned forests are no longer an attractive recreational amenity. Older forests are also no help with ameliorating the greenhouse effect because they emit more carbon dioxide than they produce.