Alistair Darling has urged governments to act on climate change and told finance ministers to "get on" with tackling the problem.
"We either take action and stop these problems happening or we fail to take action and we face bigger costs down the line," Mr Darling said.
His comments came ahead of the G20 summit taking place in Scotland this weekend.
Money has been the sticking point in a key deal on climate change, with developing countries asking for around £250 billion a year from their richer counterparts to help tackle emissions levels, according to the Daily Telegraph.
EU leaders last week agreed on a package that would see poorer nations receive around 100 billion (£89.6 billion) a year from both businesses and governments to help them meet forthcoming environmental challenges.
Earlier this week, African nations boycotted UN climate talks being held in Barcelona in protest over the level of emissions cuts developed countries are expected to make.
African leaders argue that they will suffer the most as a result of global warming yet are least responsible and are calling on rich countries to commit to higher CO2 reduction targets.