Erica starts from the premise that all of our mathematical choices have practical and ethical implications. To illustrate this, Erica will recap her mathematical career and interests, presenting some solved and unsolved problems in geometry, fluid dynamics, complex modelling, forecast evaluation and statistical inference. Using examples including climate change and Covid-19, she will demonstrate the mathematical consequences of (lack of) social diversity in the mathematical sciences, and show how our ethical standpoint as mathematicians can be fundamental to understanding and re-imagining the world around us and making responsible decisions about the future.