Forests in countries like Brazil and the Congo get a lot of attention from environmentalists, and it is easy to see why. South America and sub-Saharan Africa are experiencing deforestation on an enormous scale: every year almost 5 million hectares are lost. 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, dry places where nothing grows terribly well. When farmers give up trying to earn a living from farming or herding, trees simply move in. The second is government policy and subsidy. Throughout history, governments have protected and promoted forests for diverse reasons, ranging from the need for wooden warships to a desire to promote suburban house-building. Nowadays forests are increasingly welcome because they suck in carbon pollution from the air. 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. Parts of Spain and Portugal suffer from terrible forest fires. Others simply dislike the appearance of forests planted in neat rows. They will have to get used to the trees, however. The growth of Western forests seems almost as unstoppable as deforestation elsewhere.

解析：B。根据题干中的environmentalist’ attention可定位到原文第一段第一句。该句指出，巴西、刚果等国的森林状况引起了环保主义者的关注。随后在第二句指出，南美洲和撒哈拉以南非洲正面临大规模的森林流失：每年都有将近500万公顷的森林消失。B项与此内容相符，其中Forests are fast shrinking对应原文第一段第二句中的experiencing deforestation on an enormous scale，many developing countries对应原文第一段第一句中的countries like Brazil and the Congo和第二句开头的South America and sub-Saharan Africa，故B项为正确答案。

错项排除：原文中只是提到富裕国家的森林面积有所增加，一些发展中国家的森林在快速消失，没有提到富裕国家抢夺贫困国家的资源，故A项错误。C项利用第三段第一句中提到的abandonment of farmland设置干扰，但该句是说海拔高、气候干燥的地区的农场遭到废弃的现象尤其多，在这些地方没有什么农作物能长得好，C项中的fertile（肥沃）与该句中的nothing grows terribly well（没有什么农作物能长得好）意思相悖，而且这也不是环保主义者的关注点，故C项排除。原文第三段中提到这些富裕国家的政府对于扩大森林面积提供了政策支持和补助，D项与此内容相悖，故D项排除。