Small farmers around the world who grow thirsty crops like corn will face a huge adaptation challenge as the effects of climate change worsen in the coming years, experts warned on October 27.

The International Fund for Agricultural Development (IFAD) sounded the alarm in a report after commissioning a study on agriculture in southern and eastern Africa.

Harvests of staple crops in eight countries could plummet by up to 80 per cent by 2050 as warming accelerates, the report projected.

The study was carried by the University of Cape Town, which analysed climate impact on agriculture in Angola, Lesotho, Malawi, Mozambique, Rwanda, Uganda, Zambia and Zimbabwe.

It projected a temperature rise of around two degrees Celsius by 2069, and up to 2.6C in some places.

Corn requires a lot of water to grow, which will add to pressure on farmers to switch to strains that mature earlier, or to switch to more resilient crops such as cassava, peanuts, beans, sorghum and millet.

But moving to different crops is easier said than done, as there can be strong market preferences, IFAD said.

Farmers also face many financial and technical hurdles as they contemplate a switch, from advice on seeds and the acquisition of new tools to the processing and storage of crops to prevent spoilage.

It is estimated that less developed economies require between $140 and $300 billion annually by 2030 to combat the impact of climate change.

At present, out of every $18 committed to fighting climate change, only $1 is spent on adaptation – the rest goes on reducing carbon emissions that cause the problem.