The latest issue of The Economist features a special report on forests, which perform valuable services like sequestering carbon and regulating runoff. Because people can easily get paid for timber (or crops grown on deforested land) but not so easily for preserving forests, deforestation is rampant. As countries become wealthier, they generally start taking more actions to preserve their forests, but that process won’t happen quickly enough to avert an environmental crisis. The Economist’s leader article highlights one strategy to speed the transition – and the challenges it faces:

The main international effort to speed it up is an idea known as REDD (Reducing Emissions from Deforestation and Forest Degradation), which pays people in developing countries to leave trees standing. This is not an outlandish concept. It is increasingly common for governments and companies to pay for forest and other ecosystem services. To protect its watershed, New York pays farmers in the Catskills not to develop their land. REDD schemes aspire to do this on a much larger scale. The only notable success of the Copenhagen climate-change conference last year was a commitment to pursue them. Half a dozen rich countries, including Norway, America and Britain, have promised $4.5 billion for starters.

The difficulties are immense. REDD projects will be effective only in places where the government sort-of works, and the tropical countries with the most important forests include some of the world’s worst-run places. Even in countries with functioning states, some of the money is bound to be stolen. Yet with sufficient attention to monitoring, verification and, crucially, making sure the cash goes to the people who can actually protect the forest, REDD could work. That will cost much more than has so far been pledged. The most obvious source of extra cash is the carbon market, or preferably a carbon tax. Since saving forests is often the cheapest way to tackle carbon emissions, funding it this way makes sense.

With global climate-change negotiations foundering, the prospects of raising cash for REDD that way look poor. But the money must be found from somewhere. Without a serious effort to solve this problem, the risk from climate change will be vastly increased and the planet will lose one of its most valuable, and most beautiful, assets.

As one of the report’s articles notes, REDD will have to “provide ways for tropical countries to develop growth strategies that do not involve razing forest” in order to be sustainable. Assisting with such sustainable growth strategies could help individual countries as well as the world as a whole.