Somini Sengupta reports on the latest United Nations report to sound the alarms about the effect of carbon emissions on the planet's climate: "With world leaders gathering in Madrid next week for their annual bargaining session over how to avert a climate catastrophe, the latest assessment issued by the United Nations said Tuesday that greenhouse gas emissions are still rising dangerously."

The Emissions Gap Report, by the United Nations Environment Program, describes its findings as "bleak."

"Countries have failed to halt the rise of greenhouse gas emissions despite repeated warnings from scientists, with China and the United States, the two biggest polluters, further increasing their emissions last year," explains Sengupta.

For commentary on the report, articles by Aaron Short for Streetsblog USA and Michael Anderson for the Sightline Institute provide plenty of planning related material.

Short notes that one of the key recommendations of the report for quickly and significantly reducing the amount of carbon emissions would be to reduce the size of vehicles. To achieve that goal would require reversing the current trend in automobile preference in the United States, writes Short: "Sales of SUVs and light trucks have risen sharply over the past decade, so now SUVs represent 69 percent of the automobile market share in the U.S., up from 49 percent in 2008."

Anderson focuses on land use, noting the report's recommendation to remove legal barriers to more contact development. In fact, the report suggests a 20 percent reduction to average floor area per person by 2050. The report calls out the United States in particular for making more compact living arrangement illegal in most of the country.