Water shortages looming across Asia

Updated March 30, 2011 15:29:26

The rapid growth of urban areas in China and India will see many cities facing water shortages by 2050.

That's one of the assessments coming from a report published this week in the U-S by the Proceedings of the National Academy of Sciences. The report says within four decades 94 million people across Asia will live in cities that will have recurring water shortages. And the effects will be felt not just by humans but also by freshwater fish.

Presenter: Liam Cochrane
Speaker: Robert McDonald, a scientist with The Nature Conservancy and one of the authors of the report titled Urban growth, climate change, and freshwater availabiliy

COCHRANE: Now, can you outline for us some of the specifically where are these water shortages and pressures going to be most problematic?

McDONALD: It's really anywhere where there's fast urban growth and at least seasonally dry climates, so northern China particularly shows up, a lot of India with its monsoonal climate struggles with seasonal water shortages, and then really the perennial water shortages and mostly Middle East and North Africa.

COCHRANE: When you're talking about water shortages, what sort of amounts are we talking? I know here in Melbourne, we try to keep our water usage to 155 litres per person per day. What sort of figures are you looking at?

McDONALD: So we've use the threshold of 100 litres per person per day and we're just looking at water availability. So in developed countries, actually Melbourne is doing really well. Here in New York, we're two or three times that in most cities. But availability is really just one of three challenges for cities, so you have to have enough water nearby, you have to get it to your citizens and it has to be clean enough to drink. And right now there's hundreds of millions of people in Asia who don't have any clean water, so already there's a challenging situation. If there's going to be a few more billion people in cities, and there's going to be climate change, it's a challenge. So I think we're trying to say to folks the numbers in this paper are not destiny, they are challenged to the global community to figure out a solution.

COCHRANE: And the numbers aren't just around shortages for human needs. There are also going to be pressure on freshwater ecosystems. How great do you think that threat will be?

McDONALD: It's a very great threat. Freshwater ecoregions and ecosystems are already one of the most threatened types of natural systems on the earth and we say a dry river is a dead river. So if people are truly drinking rivers dry which has happened in the US with the Colorado River. It has really big impacts on the natural systems. So one of the things here is that it's important to find solutions that leave some water in the natural system, because of the natural world, and to try to find those solutions that work a little bit with nature.

COCHRANE: Well, let's talk about some of those solutions. What can governments and communities do, what are the most effective things they can do?

McDONALD: Well, there will have to be some new infrastructure. New long distant transport of water, new dams. When you're building huge new cities like Southeast Asia's doing, there will be some of that, but there's also huge potential for solutions that really push water efficiency. Right now in many developing countries' cities, more than half the water is lost before it gets to citizens, for example, so there's room to save water that way.

COCHRANE: And, of course, agriculture is a massive user of water and especially across the Asian region. What needs to be done in the agricultural field?

McDONALD: Yeah, that's right. Agriculture is by far the biggest consumptive use of water globally, and there's more than enough water wasted in agricultural irrigation to have water for all the urban residents in the world. The big challenge is basically farmers often don't have the money or the technological know-how to use more efficient irrigation, like drip irrigation or sprinkler irrigation so it's a question of having funds and to put those systems in and having the right incentives in place to encourage farmers to do that.

COCHRANE: And, of course, none of that comes for free. We've seen international moves to get together some money from developed countries for the use by developing countries in the area of climate change. Do we need more emphasis on infrastructure and money to spend on infrastructure to alleviate water shortages in the future?

McDONALD: Yeah, it's my opinion that we probably do, especially I worry about countries that are some of the poorest countries, like West Africa, that will have very, very fast urban growth, but don't have the resources that say a China will have and for them they can't just as a city float the municipal bond and raise money to deal with these issues, so there's definitely a role for the international community in terms of financing there.

COCHRANE: And how, I mean compared to climate change, how pressing do you think this water shortage problem is?

McDONALD: Well, I think it's very pressing and climate change interacts with urban growth, so two of them together that are making the numbers that you see in this report and you can't really separate them. What climate change is doing in our paper we shared is tending to make on average dry seasons drier and wet seasons wetter. So they'll be a lot of need to store water from the wet season's management of too much water and then carry it over to the dry season.