The third most damaging food, by some distance, is butter: one kilo of butter equals nearly 12 kilos of CO2 -- about half as many as beef. It belongs to the same supply chain, making dairy and beef cattle an environmentalist's nightmare.<br /><br />While <PERSON> have greatly reduced their consumption of red meat in recent years, the NRDC reports that butter and other dairy products such as cheese and yogurt actually enjoyed a surge in the observed period, from 2005 to 2014.<br /><br />Butter is the most climate damaging of all dairy products because there are several steps involved in producing it that are energy-intensive: ``For example, butter production requires separating raw milk into low-fat milk and cream, pasteurizing the cream, cooling the cream, ripening and churning,'' <PERSON> told CNN.