Sir

In your Editorial “Burning issues” (Nature 432, 131; 2004 10.1038/432131a) you argue that international climate treaties, such as the Kyoto Protocol, should provide incentives to reduce greenhouse-gas emissions from peatlands in Indonesia by including them in an international cap-and-trade system. In the future, one could include peatland restoration in a greenhouse-gas trading system by giving countries such as Indonesia emission targets that explicitly cover those emissions (which is not the case now). However, the difficulty of setting an appropriate target for such variable emissions should not be underestimated.

If there is a risk that Indonesia will again experience peatland-related emissions similar to those released in the 1997 El Niño event (13–40% of global emissions), it is hard to see how the country could accept a target that would make it accountable for those emissions; reasonably enough, Indonesians consider that they have little control over them.

On the other hand, offering a generous emission target, which would cushion such emission events, runs the risk of inflating the international carbon market with ‘tropical hot air’ if it turns out that the peatlands do not burn. This would have detrimental consequences for emission-reduction efforts in other parts of the world.

Clearly, these problems affect not only Indonesia but also other countries with large potential changes in their biospheric stock of carbon. Brazil, just like Indonesia, gets a large share of its emissions from deforestation. Annual fluctuations in deforestation-related emissions are as large as the entire Kyoto target for the European Union (see U. M. Persson and C. Azar, Brazil beyond Kyoto, Swedish Environmental Protection Agency, Stockholm, 2004).

In addition to problems in setting appropriate targets, there are huge uncertainties in emission estimates and difficulties in separating human-induced emissions from natural emissions.

One possible way forward is to develop a separate protocol for these highly variable emissions, based on specific policies and measures that encourage better land-use patterns and protection of sensitive ecosystems. This would avoid the uncertainties of target-setting altogether.

Alternatively, if all carbon emissions were included under the same cap, the target for such variable emissions could be made non-binding, so that carbon credits could only be claimed if emissions fell below a certain level. This would make it politically feasible to negotiate a reasonably tough target, because countries would not be held accountable for emissions exceeding the target. An incentive for peatland restoration and reduced deforestation would be created, while the risk of creating ‘tropical hot air’ would be diminished.

Finally, although there are difficulties and problems associated with almost all proposals to deal with these problems through international climate negotiations, this should not prevent us from taking action to deal with it on the ground today.