Sir

In their Commentary on the prospects of future climate change, Martin Parry et al. state that the Kyoto Protocol “is an agreement to a 5.2 per cent reduction in greenhouse-gas emissions by about 2010 (relative to 1990), and constant emissions thereafter” (Nature 395, 741; 1998 ). Any reader of the actual text will see that it says no such thing (http://www.unfcc.de).

The protocol — like its predecessor, the United Nations Framework Convention on Climate Change — sensibly takes a step-by-step approach, setting targets only for the budget period 2008-2012. What countries choose to set as future commitments, and who will be involved in those commitments, is a matter for future negotiation. Periodic review of commitments is required under the convention and the protocol. The protocol commits parties to agreeing commitments for future budget periods by 2005 at the latest.

Regrettably, therefore, some of the subsequent argument in the Commentary breaks down. It is, however, a reminder of what would happen if countries were complacent in those subsequent review periods, and a warning that even the most ambitious steps will leave some parts of the world with serious adaptation issues.

Table 1 Estimates of global warming for the year 2050
Full size table