South Asia’s rivers are again in furious flow with India’s northern state of Kashmir hit by the worst floods in 50 years. Its capital, Srinagar, has been overwhelmed by the deluge, with road links to the rest of India washed away and villagers marooned on rooftops. India’s prime minister, Narendra Modi, has declared a national disaster. However, with crops and livestock under water, a state that was re-emerging from years of conflict has suffered a cruel setback.

On the Pakistani side, the flooding has been equally devastating with more than 300 dead, 2.3 million people affected and rural livelihoods decimated as cotton fields are intentionally flooded to save cities.

We have been here before. Only four years ago an epic flood engulfed large swaths of Pakistan, displacing 20 million people across the country, leading the UN to describe it as the worst humanitarian disaster of its time.

In response to the 2010 floods, a younger generation of Indian and Pakistani leaders joined hands and created a platform to foster bilateral cooperation on shared risks and vulnerabilities. Chief among these was climate change and its manifestation in extreme weather events such as the floods, which the World Meteorological Organisation (WMO) attributed to climate change.

The efforts of these young Indians and Pakistanis led to meetings in Lahore, Delhi and Davos, starting a conversation around the climate risk faced by both countries and challenging politicians to unite around the shared necessity of climate action.

Action is now needed more than ever. Climate change is both a challenge as well as an opportunity for these two nuclear nations. It is a risk that can no longer be ignored, and has to be managed.

How to deal with the shared resource of its river waters and what to do when they break their banks in an era of climate change is a key challenge for both India and Pakistan. At the upstream end this will require improved bilateral cooperation on transboundary water management in the Indus river basin. At the downstream end this will need shared expertise and collaboration on improving disaster-risk management.

As this month has shown, cataclysmic floods present a real danger to both countries. Both have been ravaged by intense and unseasonable rainfall in the Indus river basin. On 2 September, Kashmir was hit by more than 200mm of rain in less than 24 hours – four times the average monthly rainfall. Yet the state does not have a single flood forecasting station or a disaster management department. As we saw with Pakistan in 2010, this was a disaster waiting to happen.

In its fifth assessment report the Intergovernmental Panel on Climate Change (IPCC) has strengthened its assessment that extreme rainfall will be a feature of climate change as weather patterns shift across south Asia.

While we may not be able to predict when disaster strikes, one can plan for it better and prepare accordingly. Given the shared nature of the problem, efforts at a solution too must be shared. This was the message from India and Pakistan’s young leaders in Lahore two years ago. Today it is more resonant than ever.

History is not an encouraging guide. The closest south Asia has come to a joint environmental monitoring system for floods is with the WMO-led initiative, the Hindu Kush-Himalaya hydrological cycle observation system. The project has established a regional flood information system to facilitate exchange of hydrometerological data to mitigate casualties and property damage among member countries. These initiatives are vital, but their limitations have been demonstrated by the drama unfolding in India and Pakistan.

With new prime ministers at the helm in both countries, there is a unique opportunity to exercise leadership. Both Modi and Nawaz Sharif are from border states and have shown remarkable willingness to engage in peace-building, despite persistent acrimony from their armed forces.

Acknowledging that the deadly floods are not an act of god but a symptom of climate change would be a first step towards acknowledging a common vulnerability. This could pave the way to a new era of pragmatic cooperation, embracing basic data sharing at a decentralised state level, encouraging border states (to begin with) to cooperate on climate change, water and disaster risk-management strategies. This may seem far-fetched, but existing initiatives have demonstrated a local will for cooperation. It is now for leaders to act. The stormy monsoon clouds that have brought so much misery to the subcontinent may yet have a silver lining – if they can deliver a climate peace dividend to both peoples.

• Saleem H Ali, professor and research director at the University of Queensland in Australia, and Malini Mehra, founder of the Centre for Social Markets, are the initiators of the Young Global Leade rs Indo-Pak Initiative of the World Economic Forum