"Often times when you face such an overwhelming challenge as global climate change, it can be somewhat daunting - it's kind of like trying to lose weight, which I know something about"

In this quote, Hillary Clinton is comparing the difficulty of international environment change to attempting to drop weight. She is suggesting that both jobs are hard and need a lot of effort. She is likewise recommending that she has personal experience with trying to lose weight, which offers her insight into the trouble of the challenge. By making this comparison, she is stressing the magnitude of the challenge of worldwide environment change and the requirement for cumulative action to address it. She is likewise highlighting the significance of private action, as she recommends that the same commitment and effort that is needed to reduce weight is likewise needed to take on international environment change.