Want clean water? Save your forests!

Cities can ensure they have a cheap and abundant supply of clean water by protecting and regenerating forests in their surrounding watersheds, according to a major analysis just undertaken in Malaysia.

Forests are a vital source of clean water -- and important for lots of other reasons too.

Forests are a vital source of clean water -- and important for lots of other reasons too.

Jeffrey Vincent from Duke University, USA and his colleagues have just published the largest cost-benefit analysis ever conducted in the tropics, and they find that pristine and even selectively logged forests are very cost-effective ways to produce clean, drinkable water. 

Vincent and colleagues ran their analyses under a wide range of scenarios.  They used as a baseline the costs of standard water-treatment plants, which are often required to make polluted water safe to drink.

The authors found that the relative advantages of forests depend on local circumstances, with the financial benefits being greater in some situations than others. 

Also, if one factors in profits that can be made by exploiting the forests -- such as by converting them to agriculture -- then the numbers could change. 

The problem, of course, is that waters that drain off of agricultural lands are often polluted by fertilizers, pesticides, and organic wastes, making expensive water-treatment necessary.

The authors argue that, beyond water purification, intact forests have many other financial and non-financial values. 

For instance, they store large stocks of carbon, and thereby reduce greenhouse gas emissions. 

They also can harbor enormous biodiversity while helping to attract substantial income from ecotourism.  Remarkably, it's currently estimated that protected areas across the world attract some 8 billion visits annually, underscoring their financial value for local communities.

Furthermore, via the process of evapotranspiration, forests emit enormous quantities of water vapor.  For example, one-third to one-half all the rainfall that falls on a tropical forest is quickly recycled back to the atmosphere, as water vapor.

This water vapor (plus natural organic aerosols emitted from forests) help to form clouds, which in turn reflect solar radiation back into outer space, thereby reducing global warming. 

Forests are natural cloud-makers.

Forests are natural cloud-makers.

Such clouds also help to produce life-giving rainfall during the dry season -- when forests are most drought-stressed and prone to fires.

Finally, forests are very good at reducing destructive floods.  They tend to act like giant biological sponges, trapping water and releasing it slowly, thereby reducing downstream flooding.  Especially in areas where forests are denuded, flooding can cause billions of dollars in damage and costs thousands of lives each year.

The conclusion: It's increasingly becoming apparent that it's smart to conserve pristine and selectively logged forests -- even when one uses just hard, cold economic logic. 

 

Help ALERT combat threats to crucial Malaysian park

Have a look at a global map of imperiled animals and plants.  What jumps out at you is the alarmingly high concentration of endangered species in the Malay Peninsula.  That's why ALERT's latest campaign is so crucial--helping to protect one of the most important nature reserves in Peninsular Malaysia.

Selangor Park, along with Malaysia's Central Forest Spine, is prime habitat for endangered species (photo by Gopalasamy Reuben Clements)

Selangor Park, along with Malaysia's Central Forest Spine, is prime habitat for endangered species (photo by Gopalasamy Reuben Clements)

ALERT member Gopalasamy Reuben Clements, who lives and works in Peninsular Malaysia, is helping to promote a campaign to protect iconic Selangor State ParkPlease spend 30 seconds to sign this petition--and also 'like' and 'share' this blog on Facebook and other social media.

Gopalasamy shares his thoughts with us:

The Coalition for the Protection of Selangor State Park is greatly concerned with the proposal to degazette part of the park to make way for the proposed Kuala Lumpur Outer Ring Road.

Selangor State Park is the largest intact forest tract remaining in Selangor and the third largest park in Peninsular Malaysia.  It forms part of Peninsular Malaysia’s Central Forest Spine and functions as the most important watershed for Selangor, Kuala Lumpur, and Putrajaya.

The park protects forests that are not only rich in biodiversity and imperiled species but provide crucial ecosystem services such as clean water to many residents and businesses in the greater area.

The recent dry spell in Kuala Lumpur and Selangor highlights the need to hold on to every  square inch of catchment forest.  And putting more roads through the Central Forest Spine, a vital habitat for Malaysia's wildlife, will expose endangered species to more threats from habitat loss and poaching.

Selangor Park is a vital source of clean water for a large and growing populace (photo by Gopalasamy Reuben Clements)

Selangor Park is a vital source of clean water for a large and growing populace (photo by Gopalasamy Reuben Clements)

Since 2009, many members of the public and NGOs have voiced growing concerns about the proposed road project, calling on the government to change the road alignment and not allow it to slice through the park.  But all efforts so far have been to no avail.

Now, with the project about to proceed, we need your help.  Please sign the above petition and help us raise the international profile of this vital area.  You could help us save one of Earth's most important ecosystems.