Tony Blair is expected to focus on global warming when he formally opens proceedings at the World Economic Forum in the Swiss ski resort of Davos later.
The world cannot afford to ignore climate change, Mr Blair will say
The UK prime minister will also urge international co-operation to ease the plight of African countries.
Other topics on the agenda for the five-day talks include the future of Iraq and China's economic power.
Protests against the WEF are expected to be muted after anti-globalisation campaigners called off a demonstration.
Mr Blair will make a keynote speech at the conference, which is being attended by more than 20 heads of state and government leaders.
In it, he will set out "why it is not just that the world cannot afford to ignore Africa and climate change but also the opportunities for the world in general in tackling these two issues", his official spokesman says.
He will meet aid workers, African leaders and businessmen to discuss development issues.
This will include talks with Microsoft founder and billionaire philanthropist Bill Gates, rock star and poverty campaigner Bono, Nigerian President Olusegun Obasanjo and South African President Thabo Mbeki.
Mr Blair's stance on climate change has been backed by Sustainable Development Commission chairman Jonathon Porritt.
He told reporters Tony Blair's speeches on the matter were "extremely important".
"He is one of the very few world leaders who is out there saying, 'This stuff is a great deal more important than you think it is and it is going to impact on you a great deal more forcefully than you think it is. So get your act together and get in line and start thinking how we can sort this out together'."
The themes of Africa and climate change are also expected to dominate Britain's chairmanship of the G8 group of industrialised countries, which will culminate with a summit at Gleneagles in July.