A meeting of donors in Berlin for a new global climate fund Thursday will aim to approach a $10-billion target to help poor countries cut emissions and prepare for global warming.
Hitting the initial financial goal for the so-called Green Climate Fund would be seen as a key step ahead of international talks in Peru next month, and in France a year later, on slashing worldwide carbon emissions.
The South Korea-based fund aims to help developing nations invest in clean energy and green technology and build up defences against rising seas and worsening storms, floods and droughts.
The fund aims to help those countries least to blame for, but most at risk from, climate change with grants, loans and private capital for projects such as solar and wind farms, reforestation or building up coastal defences.
The Berlin pledging event will allow the 22 countries there "to show leadership in tackling one of the greatest threats to humankind," said Hela Cheikhrouhou, the GCF's executive director.
UN climate chief Christiana Figueres has called for an initial capitalisation of at least $10 billion by the end of the year, to be disbursed over four years from 2015.
So far the fund is about three-quarters there and hopes to top $9 billion on Thursday.
The United States days ago pledged $3 billion and Japan $1.5 billion, after Germany and France promised $1 billion each, and Sweden over $500 million.
Smaller amounts totalling less than $1 billion between them have been offered by Switzerland, South Korea, the Netherlands, Denmark, Norway, Mexico, Luxembourg and the Czech Republic.
Britain is also expected to make a significant pledge Thursday, while questions remain for other EU countries as well as Canada, after Australia ruled out contributing.
- Melting ice, extreme weather -
The fund is seen as a step toward a far more ambitious goal set at the Copenhagen climate summit five years ago -- for rich nations to "mobilise" $100 billion a year for broader climate finance by 2020.
UN climate experts have cautioned there is no time to lose in the battle against global warming, which the world body's chief Ban Ki-moon last week labelled "the defining issue of our times".
The UN Intergovernmental Panel on Climate Change warned this month that time is running out to limit warming to two degrees Celsius (3.6 degrees Fahrenheit) by 2100 from pre-industrial levels.
They said Earth is on a likely trajectory for at least four degrees Celsius warming -- a recipe for melting ice caps, extreme weather events, habitat and species loss and conflict for resources.
After years that saw little progress in climate talks, the world's two biggest economies and top polluters, China and the United States, earlier this month agreed to new targets.
At a Beijing meeting, President Barack Obama committed the United States to reducing its greenhouse gas emissions 26-28 percent by 2025 compared to two decades earlier.
China, the world's top polluter, agreed for the first time to slow emissions growth and ultimately reverse it after emissions peaking "around 2030."
The 28-nation European Union, the third-largest greenhouse gas producer, has pledged to cut its emissions by at least 40 percent by 2030 from 1990 levels.
The world's most powerful economies at a G20 meeting in Australia last weekend urged "strong and effective action" on climate change, including by financing the Green Climate Fund.