The world's 10 biggest food and beverage companies – General Mills included – are both highly vulnerable to climate change and major contributors to the problem, according to a new report from the social justice group Oxfam.

The report released Tuesday concluded that the top 10 together emit so much greenhouse gas that if they were a single country, they would be the 25th most polluting nation in the world.

The top 10 aren't addressing production practices in their supply chains such as deforestation and overuse of fertilizers, Oxfam says.

Golden Valley-based General Mills and Michigan-based Kellogg were particular laggards in addressing climate change issues, the Oxfam report said.

In a statement, General Mills said it strongly disagrees with Oxfam's assessments. The company says it has had greenhouse gas reduction targets since 2005, and has pledged to reduce the emissions in its direct operations by 20 percent by 2015.

General Mills also says it has pledged to cut transportation fuel usage rates by 35 percent by the same year, and that reducing agricultural emissions is a key objective for its sustainable sourcing plans.