By creating a mathematical model which identifies where pollution goes when it enters the ocean, we can stay one step ahead of the waste and help to save our planet. In this talk, Tom discusses his research in the field of fluid dynamics, and how he has been able to construct a model which can predict where the pollution from any river, anywhere in the world will end up, using only three pieces of information widely available on the internet. For many people, mathematical formulae and calculations can be a source of anxiety, but Tom's experience and expertise will have you hanging on his every word from beginning to end, as he explains not only how we can use maths to save the planet, but how YOU can use the power of mathematical modelling to help to solve any problem you might encounter in your life. Tom Crawford is the face of the award-winning YouTube channel 'Tom Rocks Maths' and Professor Doctor at Oxford University. He also sometimes appears on Numberphile where he explains maths problems clearly. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx