Kristalina Georgieva, managing director of the IMF, warned that surging losses of land and income will drive growing migration with "people trying to get to places where they can have more security".
"Climate refugees are already part of the flow of people moving outside of Africa - and the numbers are going up," she said.
So far, global pledges to reduce emissions add up to between a third and two-thirds of what is needed to stay below 2 degrees Celsius of warming, the less-ambitious aim of the 2015 Paris Agreement on climate change, she said. That is translating into swiftly rising costs to adapt to extreme weather and higher seas, with
Shifting course would require global financial changes to drive emissions cuts, Georgieva said - from ending an annual $600 billion in direct fossil fuel subsidies to more countries putting a price on carbon to ensure the costs of climate damage are factored into products. Huge amounts more private investment are also required to boost clean energy, strengthen climate resilience and other needed changes, she said. Last year, climate-related investment rose by 50% globally - but still amounted to only a quarter of 1% of a total $49 trillion in investment funds, she said.
The U.N. Environment Programme estimating $140 billion-$300 billion will be needed annually by 2030 for developing nations to cope with impacts.
At least $30 billion-$50 billion of that is needed just for sub-Saharan Africa, according to IMF estimates, Georgieva said.
Sea level rise and worsening floods are already costing $3.8 billion a year in West Africa, with total losses across the continent running at about $7-8 billion a year, said Akinwumi Adesina, president of the African Development Bank Group. That includes $2 billion in damage in southern Africa from cyclones in recent years, as well as losses of a million hectares of crops to locusts and other damage from floods in East Africa and more land becoming desert in the Sahel, he said.
President Felix Tshisekedi of the Democratic Republic of Congo, the current head of the African Union, said finding funding to help Africa cope with the rising harm was crucial. "The fight against climate change cannot be won unless it is won in Africa," he told an event on accelerating African adaptation at COP26.
Georgieva urged all countries to act as fast as possible to tackle climate threats and speed up efforts to reduce emissions.
"Rich countries have to do more, emerging markets have to do more, poor countries have to be helped to do more," she said. "If we don't take charge of our own destiny in this decade, it doesn't matter how beautiful our plans for 2050 are – they will not materialise," she added.