DW: Experts link Pakistan's water shortage to mismanagement, but is there also a connection between the country's water crisis and climate change?

Tariq Banuri: Pakistan has witnessed a number of floods in the past several years, and long spells of drought which, experts believe, are a result of climate change. Pakistan's rain pattern is already that of high magnitude and low frequency, which means we have more rain but for a shorter time, which does not help percolation and raise the ground water level. So, climate change is causing longer spells of drought, which is complicating our water scarcity problem.

But climate change is not the sole cause of water scarcity; exponential population growth is also contributing to this crisis. For instance, at the time of Pakistan's independence in 1947, the population was low, and therefore the per capita water availability was more than 5,000 cubic meters per person per day, which made Pakistan a water-abundant country at the time. But today, it has fallen below 1,000 cubic meters per person, which is why we say that Pakistan is a water-scarce country.

In future, though, climate change will make matters worse in a number of ways. First, as mentioned above, the total quantity of water is likely to decline, thus increasing the scarcity level. Second, the water availability will become more erratic, thus increasing uncertainty and seasonal stresses and strains. Third, the increased temperatures will reduce water availability further because of higher evaporation rates while increasing crop water requirements and other water demands.

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Does that mean that climate change is triggering droughts in some parts of the country?

Pakistan has already experienced severe droughts in its southern region (especially Tharparkar in Sindh province) in 1998-2002 and 2014-17. It will most likely intensify because of the climate change, which threatens the situation in a number of ways.

First, if glaciers continue to decline, the contribution of snow and glacier melt will ultimately decrease. Second, climate change will also affect the monsoon patterns (although current projections do not show systematic changes in this regard). Third, the higher temperatures throughout the country will increase water demand as well as evaporation. All three factors are likely to contribute to an increased frequency of droughts.

But there are contradictory reports about the melting of glaciers in Pakistan. What is your take on this?

The Indus Basin System is fed by glaciers from three interconnected mountain ranges, namely the Himalayas, the Karakorum and the Hindukush. Of the three (also known as the HKH region), the glaciers in the Himalayas and the Hindukush are melting, similar to those in the rest of the world. The Karakorum, however, appears to be behaving in an anomalous manner; for example, some glaciers are stable, others are melting, and some even appear to be increasing. This has puzzled scientists because no one expects glaciers to remain stable when temperatures rise.

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Experts say that climate change is also changing the rain pattern in Pakistan. How will it impact the water crisis in Pakistan in the coming years?

This is a rather complex question. There will be lower rainfall in some areas and higher in others. Also, rainfall may become more concentrated, more intense for a short period.

Some experts say that Pakistan is likely to "dry up" by 2025. Do you agree with this assessment?

"Dry up" is a sensational phrase that scientists prefer not to use. As I said earlier, the recent trends suggest that aggregate water flows may have declined a little bit, but we are not sure whether this is temporary or permanent. In future, most projections show a declining trend and an increased variability of the flows. Most projections look at the next 50 or 75 years, rather than the next 10 years. The most urgent problem in Pakistan in this regard is population growth, which reduces the average water availability every day.

Climate change will make it much worse. So, we advise that the authorities control population growth, carry out forestation and vegetation that helps percolation and in-filling of natural aquifer that serves as our water storage facility.

Does Pakistan's development policy take climate change into account?

Pakistan needs to have a development strategy that draws benefits from the direction in which the world economy is moving, so that we are not left behind while everyone else makes a successful transition to a low carbon economy.

Read more: Pakistan's urbanization: 'A challenge of great proportions'

Dr. Tariq Banuri is the Executive Director of the Global Change Impact Study Center in Islamabad.

The interview was conducted by Sattar Khan.