The science is in: Human activity is warming the planet. As world leaders prepare to gather for a U.N. climate summit in Glasgow, Scotland, to address the “code red for humanity” posed by climate change, Yahoo News explains the leading causes and sources of emissions that lead to global warming. Follow us on: Facebook: https://www.facebook.com/yahoonews Instagram: https://www.instagram.com/yahoonews/ Twitter: https://twitter.com/yahoonews TikTok: https://www.tiktok.com/@yahoonews Website: https://news.yahoo.com/