Unchecked climate change risks plunging a further 175 million people into hunger and undernourishment worldwide, undermining progress in reducing food insecurity, a US government report warns.

The US Department of Agriculture analysis states that climate change is “projected to result in more frequent disruption of food production in many regions and in increased overall food prices”.

The impact of rising temperatures is expected to hit poor people and tropical regions the worst, while those in colder, higher-latitude areas could experience improved agricultural capacity. However, from 2050 onwards, every food-producing region in the world is expected to be detrimentally effected.

Under a “business as usual” scenario where global greenhouse gas emissions are not significantly cut and temperatures rise by around 4C (7.2F), the report estimates that an extra 175 million people will be undernourished by 2080. This is in addition to the number of people already going hungry today, estimated to be about 795 million by the UN.

Population growth, with an extra two billion people expected on Earth by 2050, “increases the magnitude of the risk”, especially when combined with social and economic changes that alter the types of foods demanded by consumers, the USDA report states.

Increasing temperatures, altered rainfall patterns and reduced availability of water in some areas will affect food production, while sea level rises – of up to a metre by the end of the century – and extreme heat may hamper the transportation of food.

The USDA report predicts that adaption and new technology will help this situation, as well as decisions on global trade that will dampen any spikes in food prices. An effective deal to reduce greenhouse gas emissions – which is currently being negotiated in Paris – would also be beneficial, although nations’ commitments thus far would still result in an average temperature rise of at least 2.7C with significant consequences for agriculture.

“The past six years have been a success story in terms of global food security,” said Tom Vilsack, the US agriculture secretary. “Two hundred million fewer people are food insecure today than they were six years ago. The challenge we now face is whether we can maintain and even accelerate this progress despite the threats from climate change.”

The USDA recently unveiled a range of voluntary programs aimed at farmers that would, if adopted, result in a reduction of 120 million tonnes of carbon dioxide by 2025.

Food insecurity has become a key topic at the Paris summit, with scientists at the talks revealing research that the world has lost a third of its effective arable land in the past 40 years due to erosion and pollution.