Today is World Water Day. Water is one of the world’s most valuable resources; an essential part of life. Without it, people couldn’t grow crops to feed their families or sustain themselves and their livestock. Too much water, from flooding or tsunamis (like the ones in Japan recently and in the Indian Ocean in 2004) can be devastating. Climate change isn’t just about the world getting a bit hotter. It’s the effect that this temperature rise has on the ecosystem and the people that rely on it for survival. Man has developed around the climate being stable, so when it changes things can get very difficult. The Converging World has been looking into the impacts of climate change already being seen in Tamil Nadu, Southern India, where we work. There are already huge impacts on the region’s water supply, perhaps unsurprisingly, and the future is uncertain. Tamil Nadu gets much of its water during the monsoon seasons. Climate change is already changing the monsoons and it is unclear what the long-term trend will be. Longer (or more intense) monsoon seasons could mean more flooding, shorter seasons could mean more droughts. The rainfall from the one year’s monsoon in the mountains affects the river flow the next year downstream. Extreme rainfall events also affect soil erosion. Anecdotal evidence from the region also suggests that rising sea levels means more salt in the soil in the coastal areas, affecting crop yields. There are 66 million people living in Tamil Nadu, most of them in big cities like Chennai. But where does their food come from, and where do they get their drinking water? Will Tamil Nadu’s farms be able to support its population in the future if climate change causes long-term changes in the regional water cycle? At CoP16 in Cancún, Mexico, the world promised $30bn of aid for climate change adaptation, it is essential that this money is made available and used in the best way possible. TCW’s full report on climate change impacts and adaptation policy in Tamil Nadu will be available soon, you can read a summary of the findings here.