What was the carbon footprint of your dinner last night - or the food you'll grill this Labor Day weekend? Agriculture is a huge emitter of greenhouse gases associated with climate change. This is an important emerging topic as Americans grapple with recent heatwaves, storms and other weather extremes as "the face of global warming" (and you may have heard our discussion of water and meat consumption on "KNPR's State of Nevada").

Climate scientists increasingly focus on food production as a source of heat-trapping gases. We'll discuss which foods have the lowest environmental footprint (fruits and vegetables) and which have the highest (red meat and dairy), and why. What's fascinating is that public health experts recommend that we emphasize in our diets the same foods that scientists regard as most climate-friendly. That's the connection between diet and climate.

Meanwhile, landmark changes in USDA school meal requirements take effect nationwide in the academic term beginning Fall 2012. We will explain the new rules (which mandate that more fruits and vegetables be served to children), based on the Healthy, Hunger-Free Kids Act signed by President Obama. We explore a new movement on hundreds of college campuses for more "sustainable dining", as well as the coming changes in public school cafeterias.