Americans have just endured one of the coldest winters in memory, so global warming may not be on their radar. But a new U.N. panel report has just refocused the public debate on a problem some scientists call the greatest threat facing the world.

There is trouble ahead for global agriculture, warns the influential Intergovernmental Panel on Climate Change, if measures are not taken quickly to reduce greenhouse gas emissions. The panel, which synthesizes the findings of thousands of peer-reviewed studies every seven years, has issued a report card on the state of the planet.

The report card serves as a guide to policymakers and a basis for international deliberations, including the summit on global warming and greenhouse gas emissions scheduled to be held in Paris next year. The report will be officially released on Sunday in Yokohama, Japan, but an advance copy has been leaked.

This IPCC report predicts that by the end of the century, “hundreds of millions of people will be affected by coastal flooding and displaced due to land loss,” the majority living in island nations and in southern Asia.

The report goes on to link food price increases (like the 2010 spike in wheat prices that helped spark the Arab Spring) to climate change-related droughts and floods. It forecasts that prices will continue to rise as grain yields decline by as much as 2 percent per decade for the rest of the century, while demand is projected to rise by 14 percent per decade through 2050.