Home | Dossiers | Is the world getting saltier?


 Yes it is! And here is some of what it means:

  • Around 20% of all the arable land in the world is irrigated. Around 20% of all the irrigated land suffers from salinization. This means that salt levels in the soil have built up to such a high level that nothing can grow on that land anymore. We are losing 1.6 million hectares this way every year. This offsets much of the progress we make towards achieving greater agricultural productivity, food security and poverty reduction.
  • With Climate Change and rising sea levels, the saline sea waters are pushing harder and harder to infiltrate onto the land and into our aquifers. Human activities (such as sand mining or over extraction of groundwater in coastal areas) are accelerating the process.
  • Salinization is not a rural/agricultural issue. It affects cities in very direct ways. Urban freshwater resources are getting increasingly salinized due to seawater intrusion, activities in neighbouring rural areas and improper management of human waste. This makes cities outgrow their freshwater reserves faster. More money and energy then has to be spent on treatment and supply, making water (and pretty much everything else) more expensive and a greater burden on the environment.

These are but a few of the hazards that befall us, simply because we are not doing a good job of managing the salt dissolved in the water that we use (and dispose). Build-up of salt levels in land and water is a gradual process, and not something we observe until it turns into a problem. This does not mean that there aren’t solutions, but only that we don’t act until its too late.

For example, it is quite well-known that all irrigation (except rainfed) builds up salt-levels in the soil. And that proper drainage of the irrigation flows will keep the soil salinity under control. But even as the total area under irrigation schemes continues to grow, we are investing very little in drainage systems to go along with them. “Irrigation is the need for today, salinization is a problem of tomorrow” is a voice that echoes across farmers, engineers and government departments alike (here is an account from India).

Outside of agriculture, the problem of salination impacts urban communities in many ways. Even the regular  movement of water through urban water systems is bound to build up salt content in aquifers and other sources, over a period of time. Deltaic and coastal cities are always up against seawater intrusion, with excessive extraction from aquifers (which happens in most cases) adding to the problem. Besides, cities produce a lot of waste. That waste contains salt, and is ultimately disposed in a way that brings it in contact with freshwater sources. Even when we treat the water extracted from these sources before using it, we are not taking the salt out of it. Gradually, salt-levels build up to a point when water from this source has to be salinized before it is used, and then water supply becomes too expensive and energy-intensive. Again, if we account for the gradual build-up of salt that we know happens but do not immediately see, we would find it worth investing in managing our waste better.

On this theme page on TheWaterChannel, where we ask “Is the world getting saltier?,” and try to bring together videos, webinars, resources, links, discussions, articles and blog posts that would help answer this very important question and raise others that we need to ask. But this is not a static repository. We urge you to participate: comment, voice your opinion, share your knowledge and post your videos…

… because we cannot continue to ignore salt just because we don’t see it!