What challenges lie ahead as the United States tries to construct a working system for greenhouse-gas regulation? Jeff Tollefson reports.

The international treaty drawn up to tackle ozone-destroying substances is gearing up to curb greenhouse gases.

Minor progress in Poland on adaptation and deforestation sets the stage for Copenhagen in 2009.

Research that argues dams have no direct effect on the migration of juvenile salmon is roiling waters in the US Pacific Northwest. The study, published in PLoS Biology, uses a new way to tag fish to compare the heavily dammed Columbia River system
with the free-flowing Fraser River to the north in British Columbia, Canada.

The Intergovernmental Panel on Climate Change (IPCC) elected new leadership last week in Geneva, Switzerland, unanimously re-electing the Indian economist Rajendra Pachauri as chairman but choosing new heads of the three working groups that coordinate the writing of its massive reports.

The lay-off last week of a senior political scientist involved in helping poor countries prepare for climate change has exposed a stark division in opinions on the core purpose of a key US climate-research institution. The National Center for Atmospheric Research (NCAR) in Boulder, Colorado, says its hand was forced by several years of largely stagnant budgets. These have resulted in the loss of 12% of its core workforce during the past five years

More than 40 negotiators from Asia, Europe and the United States converged on Washington DC last week for what was billed as the first major war game involving global warming. The Center for a New American Security, a Washington-based national-security think tank, gathered together climate scientists and experts in security, environmental policy and business for the role-playing exercise.

China burns more coal than any other country; how it does so in the future will determine our planet's climate.

A high-profile group of thinkers has come up with a straightforward way to integrate long-term forest management into an international agreement on halting deforestation. It is not clear whether the proposal

Ocean-fertilization advocates suffered another setback last week as 191 nations agreed to a moratorium on large-scale commercial schemes to mitigate climate change. The agreement, adopted on 30 May at a meeting of the United Nations Convention on Biological Diversity in Bonn, Germany, calls for a ban on major ocean fertilization projects until scientists better understand the potential risks and benefits of manipulating the oceanic food chain.