Neotropical rainforests under assault from infrastructure & mining

Everywhere you look across Central and South America, native ecosystems are being imperiled by an avalanche of new mining and infrastructure projects. 

Forests under assault in Panama  (photo by William Laurance)

Forests under assault in Panama (photo by William Laurance)

Consider just three examples:

- In Nicaragua, a massive interoceanic canal project threatens vast expanses of rainforest and other ecosystems.  It will imperil 4,000 square kilometers of forest and wetlands, slice across several key nature reserves, and cut through the MesoAmerican Biological Corridor.  This issue is so worrisome that the Association for Tropical Biology and Conservation, the world's leading scientific organization devoted to tropical research, issued a special resolution of concern.

- In Brazil, many protected areas are under assault from mining.  A paper just published in the leading journal Science shows that at least 20% of all Brazil´s strictly protected areas and indigenous reserves -- an area larger than the UK and Switzerland combined -- are under consideration for mining projects.  More than 44,000 square kilometers of Brazil's protected areas have been lost to mining and other developments since 2008.

- Across the Amazon basin and Andes, at least 150 major hydroelectric dams have been proposed or are under construction.  These projects will not only flood large expanses of forest but their associated road projects will imperil some of the basin's most remote and biologically important areas.  For instance, it is estimated that 12 dams proposed for the Tapajós River in Brazil would result in nearly 1 million hectares of additional forest loss by 2032.

Who is responsible for this tsunami of forest-destroying projects?  There is no single cause, but China's unquenchable thirst for natural resources, the aggressive Brazilian development bank BNDES, and ambitious regional development schemes such as IIRSA are all leading contributors.

No one wants to halt responsible economic development, but this is a feeding frenzy.  Unless scientists and conservationists have a louder voice, some of the world's most important environments could be lost forever.


A drier tomorrow? New study predicts less rain across planet

Expect things to get drier.  That's the alarming conclusion of a new study that projects large swaths of the Earth--including the Amazon, Central America, and Indonesia--to have fewer days with rainfall in the future.

No smoking, please.... (photo by Jedediah Brodie)

No smoking, please.... (photo by Jedediah Brodie)

Precipitation is a notoriously difficult thing to predict.  For instance, different global circulation models--supercomputer simulations of future climates--often make wildly varying predictions about future rainfall.

But the new study, which seems surprisingly robust, focuses on how changing climates could affect daily rainfall in the future.  It finds that rainforests and Mediterranean ecosystems could have as many as 30 fewer days of rainfall each year.

In many parts of the world, such changes could lead to major tipping points.  For instance, large expanses of the tropics support rainforests that suffer periodic droughts and are already near their environmental limits.

The big worry is that declining rainfall could interact with rampant land-use change--such as habitat fragmentation, logging, and slash-and-burn farming--to create massive wildfires. 

In the late 1980s, for instance, wildfires scorched millions of hectares of forest in the Amazon and Borneo. 

The one-two punch of drought and human land-use change was fatal for many forests.