COP 21: Why does Paris climate change conference matter?This video can not be playedTo play this video you need to enable JavaScript in your browser.COP 21: Why does Paris climate change conference matter?CloseBBC environment correspondent Matt McGrath asks what nations want from the climate change conference in Paris - and why it matters.Climate change special reportSubsectionScience & EnvironmentPublished23 November 2015Shareclose panelShare pageCopy linkAbout sharingRead description