With the UN Climate Summit just around the corner on Sept. 23, Paul McCartney is renewing his efforts to expand support for the Meat Free Mondays campaign he started in 2009.

"Hey, hi there. Paul speaking. Listen, I need your help," McCartney tells fans in a new YouTube clip titled 'An Urgent Call to Action.' "All I want you to do is just log in on pledge.meatfreemondays.com and pledge your support to the idea of Meat Free Mondays. All you need to do. I need your help. Please do it -- we'll send all these pledges to the politicians, and then they'll do something about it. So I need your help. Please, just log in."

This isn't the first time McCartney's tied Meat Free Mondays in with a UN conference. In 2012, he wrote an impassioned letter on behalf of the campaign to a number of politicians involved with that year's Framework Convention on Climate Change, arguing that encouraging people to cut down on meat consumption -- and thus curtailing the massive resources required by commercial agriculture -- could "make a considerable difference to the future of the planet."

McCartney has also published a 'Meat Free Monday Cookbook,' offering recipe ideas contributed by Sir Paul as well as his daughters Mary and Stella, along with famous friends such as Twiggy, Vivienne Westwood and Kevin Spacey. So go ahead and pledge -- what's so hard about boiling a box of pasta one night a week if it makes a former Beatle happy?