FORESTS in countries like Brazil and Congo get a lot of attention from conservationists, and it is easy to see why. South America and sub-Saharan Africa are experiencing deforestation on an enormous scale: every year almost 5m hectares are lost, net. But forests are also changing in rich Western countries. They are growing larger, both in the sense that they occupy more land and that the trees in them are bigger. What is going on?

Forests are spreading in almost all Western countries, with the fastest growth in places that historically had rather few trees. In 1990 28% of Spain was forested; now the proportion is 37%. In both Greece and Italy, the growth was from 26% to 32% over the same period. Forests are gradually taking more land in America and Australia. Perhaps most astonishing is the trend in Ireland. Roughly 1% of that country was forested when it became independent in 1922. Now forests cover 11% of the land, and the government wants to push the proportion to 18% by the 2040s.

Two things are fertilising this growth. The first is the abandonment of farmland, especially in high, parched places where nothing grows terribly well. When farmers give up trying to eke out a living from olives or sheep, trees simply move in. The second is government policy and subsidy. Governments have protected and promoted forests for diverse reasons, ranging from the need for wooden warships to a desire to promote suburban house-building. Increasingly they welcome forests because they are carbon sinks. The justifications change; the desire for more trees remains constant.

The greening of the West does not delight everyone. Farmers complain that land is being taken out of use by generously subsidised tree plantations. (They get subsidies, too, but the ones for tree-planting are especially generous.) Parts of Spain and Portugal are afflicted by terrible forest fires. These burn especially hot in areas with lots of eucalyptus trees—an Australian import that was planted for its pulp but has spread of its own accord. Others simply dislike the appearance of conifer forests planted in neat rows. They will have to get used to the trees, however. The growth of Western forests seems almost as inexorable as deforestation elsewhere.