Asia At Risk: Erratic Rivers & Rains

by China Water Risk 30 October, 2025

Asia At Risk: Erratic Rivers & Rains – Our global water cycle has behaved “erratically” for 6 years now, either bringing too much water or not enough of it. The same is happening to the water flows of our “mother rivers” which carry 50% of the total GDP of 16 countries as well as the lives & livelihoods of 1 in 2 Asians. So, this month, we dive into how rising river risks will threaten Asia’s growth plus explore why the Ganges River is drying faster than ever. Yes, it matters as the Ganges generates 44% of India’s GDP!

Given what’s at stake, hedging against water risks is no longer a nice-to-have but a necessary strategy to stay afloat. So how do we know we are prepared? Are there global benchmarks for measuring adaptation efforts? Here, Feng Hu, who’s been working on the UNFCCC’s indicators for the Global Goals for Adaptation shares his insights on the progress. As weather intelligence will also play a key role in building resilience, we speak to HKUST’s Prof. Fei Chen on why it is still so hard to predict rain and how AI can help in this space.

Asia’s growth has been driven by 10 “mother” rivers that flow from our Himalayan Water Towers to 16 countries. Our new report, No Water, No Growth 2, co-authored with China’s national research institute IGSNRR-CAS finds increasing pressure on these rivers. In less than a decade, the rivers saw a huge influx of population the size of around half the USA and a rise in GDP of US$6trn; US$4.6trn of this was driven by the Yangtze. FYI, the 2023 GDP of Japan was only US$4.3trn.

We must pay attention to these increasingly erratic river flows as 2bn people, over US$10trn of GDP & 800GW+ of power assets are clustered there. Exposure to these 10 rivers varies by country… a shocking 8 countries have >80% of their population and/or GDP concentrated in these basins. Worst still, national reliance on a single river can be as high as 100%. Don’t get caught out, find out which countries these are.

Liquidity constraints to future growth are worse for rivers which already have large basin areas facing ‘high’ to ‘very high’ water stress. The Ganges is one of these. University of Manchester’s Mehebub Sahana urges that saving the Ganges is more critical than ever. He says the river is a lifeline for more than 650mn people, but groundwater extraction & human engineering are straining the river.

Moreover, global warming is making monsoons more erratic plus glaciers are melting faster – all these lead to less source water. Irresponsible use of water combined with climate impacts mean the Ganges is facing its worst drought in 1,000+ years. So how can we rethink river management? Can India, Bangladesh & Nepal which share the river work together? Can we afford to fail? Check out his article.

Indeed, our new report shows that over 6x the water is used to make a dollar per resident in the Ganges than the Yellow, which is also water stressed. This shows clear room for waternomic improvement. Like China, India must generate more GDP per drop. China has more than tripled both GDP & GDP/pax in the Yangtze and almost doubled these for the Yellow while reducing water use/pax in both rivers. See China’s 8 key mountains-to-oceans actions to protect its rivers.

With escalating water risks, safeguarding our “mother” rivers should be prioritised. This should be central to climate adaptation but how will we align transboundary efforts as well as public & private sectors towards adaptive outcomes? The UN’s Global Goal on Adaptation (GGA) aims to do just that.

Given that over 90% of disasters are water-related, water is one of seven thematic targets in the GGA. We hear from Feng Hu, who sits on the UN technical expert group tasked to develop metrics for the GGA, on why water matters here. He gives us the behind-the-scenes scoop into how the indicators came about and what we can expect to see at COP30.

Yet Hu points out a critical gap – most water indicators focus narrowly on infrastructure & services, overlooking systemic risks and particularly, the cryosphere, despite its rapid decline and cascading impacts. Sadly, this “blindspot” will only further exacerbate risk gaps which are already widening as climate impacts outpace adaptation.

Costs are also mounting. Extreme weather such as floods & droughts have already cost the 16 countries a total of US$389bn in the last decade. Slower moving chronic risks are also moving faster – all key components of river flow from glacial melt, snowfall and monsoon patterns are already changing today. Amid such unprecedented changes, the ability to anticipate climate disasters before they come will save lives & money.

Advances in weather intelligence is what to watch. And there are gaps to address/invest in – did you know that heavy rains from thunderstorms are notoriously more difficult to predict than typhoons? And that existing rainfall models are less useful for tropical Southeast Asia as they were historically developed for the mid-latitudes like Europe & North America?

We unpack these with HKUST’s Prof. Fei Chen. He leads a team of researchers who are developing ultra-high-resolution urban weather models for the tropics to understand not just how much rain is coming but how it will impact city resilience.

With climate change shifting the baseline of “normal” and “extreme” events, accurate forecasts will be crucial for city planners, emergency managers and businesses to adapt to a new climate normal. Annual revenue for weather intel is projected to grow 16-fold to US$40bn by 2050 – so don’t miss out on our interview & check out which research opportunities have the greatest growth potential.

There’s still much uncertainty around predictive models but what’s clear from our report scenarios is that there will be erratic river flows & rains, yet development & rising urbanisation will only increase already clustered risks in our river basins.

The future of Asia will rise & fall with its rivers, and we must not let fears over dams distract us from collaborating to tackle the triple threat to our rivers. Some rivers will see large upticks in flow from accelerated melt and more rain, which ironically dams can help alleviate.

Asia is at risk and source-to sea collaboration on rivernomics is the only way we will survive a changing climate. With less time to prepare for mounting risks, we must act now. Rivers carry so much more than water, they carry life. Because of this, we must not fail.

Author: Jamie Chan

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