William Brangham:

If we don't quickly change the way we grow our food and manage the land on Earth, we will not be able to avoid the worst damages from climate change.

That grim assessment comes from a new report issued today in Geneva by the United Nations Intergovernmental Panel on Climate Change. Over 100 experts from 53 nations contributed to the report.

The report details a global feedback loop, where our land management makes climate change worse, and then climate change impacts the land even more.

Right now, how we grow food, chop down forests and drain wetlands contributes about 23 percent of human greenhouse gas emissions. For example, the report notes that soils essential for growing food are being lost 10 to 100 times faster than they're replenished.

As that soil degrades, crop yields will fall, and the soil itself loses its natural ability to absorb greenhouse gasses, which then makes climate change worse, and perpetuates the cycle.

According to the report, about 500 million people live in areas that are turning quickly to desert. These millions of people are increasingly vulnerable to heat waves and floods, and may soon find their homes unlivable.

The report does offer some hope, pointing out how better land management could reverse some of these trends. It also suggests things like reducing food waste, because one-third of all food that's produced gets wasted, and shifting our diet away from meat, which requires far more energy to produce than a plant-based diet.

For more on what this report says and how we ought to respond, I'm joined by Janet Ranganathan. She's the vice president for science and research at the World Resources Institute.

Welcome to the "NewsHour."

This report seems to lay out the essential paradox of modern life, which is the way we have grown food and managed the lands all over the planet have built this incredible society that we live in, but now we realize that those exact methods imperil that society, right? Isn't that what this is saying?