The sound of chainsaws in the Amazon rainforest has faded in recent years as deforestation has slowed, last year dropping to less than one-third of its long-term average. But last week, the lower house of Brazil’s
National Congress passed a bill that observers say could drastically reduce forest protection.

As the next IPCC assessment nears, scientists use palaeoclimatic data to hone their models.

Methane leaks during production may offset climate benefits of natural gas.

Keeping track of a country’s greenhouse gases is an accounting problem of epic proportions. In the United States, scientists have relied on a mix of methods to build up their national emissions inventory, including monitoring the electricity output of a power plant and assessing the quality of the fuel that powers it.

Buses spew clouds of black exhaust fumes in Mexico City while, in India, wood burnt in rudimentary stoves fills houses with sooty smoke. Methane leaks from gas pipelines in Russia and rice paddies in China, eventually breaking down in sunlight and contributing to the production of smog and ozone. In each of these cases, simple steps to curb air pollution would promote public health; scaled up, they may offer the only realistic way to tame global warming over the next few decades.

Marathon talks enable Europe to break deadlock over global-warming deal with major greenhouse-gas emitters.

To save the Amazon, Bruce Babbitt wants to isolate islands of oil and gas production amid a sea of trees.

Approval draws criticism over transparency and safety tests.

A tough-minded law has boosted Brazil's environmental record in recent years by helping to drive the rate of destruction in the Amazon rainforest to historic lows. But a backlash in the hinterlands is threatening to weaken the country's forest code and push deforestation rates back up again.

Ready or not, the era of big data is coming to ecology. After years of discussion and debate, the United States is moving forward with an environmental moni­toring network that promises to help transform a traditionally small-scale, local science into a continental-scale group enterprise.