News Update: Brazil’s rejected the $22 million in aid pledged at the G7.

The Amazon, the greatest reservoir of fresh water and biodiversity on the planet, is burning. Its degradation, which threatens to reach a catastrophic tipping point, means less oxygen and rain as well as warmer temperatures. Human actions have been the driving cause. In Brazil, which holds 60 percent of the Amazonian rain forest, wildcat land grabbers and ranchers, who set fires to clear land in implicit partnership with a lenient government, are the main culprits.

We have been here before. In 2004 deforestation rates were much worse than they are today . In the last years of that decade Brazil stepped back from the brink and imposed constraints on what had been a free-for-all in the region. We now need to be more ambitious than we were then.

The threshold problem is land tenure. Less than 10 percent of the land in private hands has clear title. Chaos reigns: No one knows who owns what and pillage is more rewarding than either preservation or production. To overcome the chaos we must distinguish long-term squatters committed to making a life in the Amazon from predatory ranchers and loggers, and award them full ownership.

In 2009, a law established the legal basis for this vital change by organizing the distribution of federal land in the Amazon. Successive federal administrations have been slow to carry it out but the state governments are ready to step in.