There is an ever-widening chasm between the support developing countries need to adapt to climate change and the funding promised and delivered by wealthy nations. While UN climate meetings endlessly debate terms such as "new and additional" or "balanced allocation", even some basic commitments to adaptation funding are going unfulfilled. And as we approach the final year of the "fast-start" phase for climate finance, there is no plan for the crucial "scale-up" period of 2013-2019, when contributions must swell tenfold.

At the Durban negotiations, countries should take three steps to ensure the developed world can meet its agreed responsibilities: establish funding sources based on international trade; define annual targets for the scale-up; and adopt a transparent, centralized accounting system.

Promise 1: Adequate finance

Parties have agreed to take "precautionary" and "adequate" measures to anticipate climate change, prevent or minimize its causes and reduce its adverse effects. This means taking action even amid scientific uncertainty.

The types and sources of funds are also an issue. It is not clear what proportion of adaptation funding will be pure grants, loans with concessionary terms, or purely market-rate loans. Vulnerable countries are not able to repay loans for adaptation, nor should they have to. In addition, the Cancun texts promise 'predictable' funds, which is essential for developing countries to budget and plan for adaptation responsibly. But predictability has not increased since the 2009 meeting in Copenhagen, as wealthy governments have not mustered the will, political support or taxes to raise climate finance.

"Scaled up" is another phrase that has not been adequately addressed. After years of watching wealthy nations put token voluntary contributions into UN climate funds, developing nations pushed for meaningful, scaled-up funding at Copenhagen.

Finally, Copenhagen and Cancun also promise "new and additional" funding. These much-debated words suggest climate finance will be over and above conventional development aid known as Official Development Assistance (ODA) - but their meaning in practice has been ambiguous.

Promise 2: Fair burden sharing

Most donor countries have similarly failed to justify the way they divide the burden of confronting climate change.

A recent study found that only two of 10 contributors that reported their fast-start finance activities to the UNFCCC indicated how they calculated their fair share of funding.

Promise 3: Balanced funding

The Copenhagen Accord and Cancun Agreements promised balanced allocation between adaptation and mitigation. Fast-start donors have pledged between $4.8 billion (3.59 billion euros) and $6.3 billion to adaptation, 19-25 percent of total climate finance - only a small rise on the 11-15 percent pledged a year ago.

Promise 4: Needs-based targeting

Adaptation funds should go first to those most vulnerable to climate impact, as promised in several recent agreements, including Cancun. Vulnerable groups are not only geographically exposed to physical threats such as sea level rise, drought or disease, but are especially susceptible to harm because of poverty and powerlessness.

Promise 5: Transparent, recipient-driven governance

Despite pledges of transparency in Bali, climate finance has been poorly reported and impossible to track and verify. Climate finance is highly fragmented, with dozens of donors, including governments, multilateral agencies, private foundations and civil society organizations. With so many funding channels and very little information, it is difficult for both donors and recipients to assess where money is going. Developing countries are left not knowing how much support to expect, when and for what.

Meeting the promises in Durban

There are three essential steps Durban delegates should take toward robust, effective adaptation funding that fulfils past promises.

First, the normal source of development assistance - national treasuries raising tax revenues - seems unlikely to provide adequate and predictable funding.

To fund the scale-up period and beyond, Durban negotiators should work out a series of financing mechanisms that are international, constant and substantial in size. A truly adequate amount to green the global economy and buffer societies from climate impact would be far above $100 billion a year - and the scientific uncertainties around the exact figure do not obviate responsible action.

Second, climate finance negotiations have a blind spot: the scale-up period from 2013 to 2019. In this period - after the fast-start years but before the $100 billion-per-year pledge for 2020 - developed nations need defined targets for each year and mechanisms to keep the expansion of funding on track. Only then will they develop systems capable of generating the amounts committed by 2020. Without annual targets regularly met, cynicism will replace any goodwill created with the Copenhagen and Cancun pledges.

Third, notwithstanding the creation of United Nations Framework Convention on Climate Change (UNFCCC)-led funds, most money in the next few years will likely flow bilaterally or through multilateral channels not governed by the convention. This makes transparency and central accounting even more crucial. Durban negotiators should create a central accounting framework and registry, perhaps under the UNFCCC's Standing Committee; provide a global definition of "new and additional" adaptation finance; and agree to standardize a format for more precise project-level reporting of financial flows.

The future of two decades of climate diplomacy is on the line in Durban. It is pivotal that any agreement going forward specify and deliver on fair and effective funding, as was promised in Copenhagen and Cancun.

The funding must be adequate and predictable, and be delivered justly and transparently. Poor and vulnerable nations should be the first to receive funds, and should have a say in fund governance. The final year of fast-start climate finance is upon us, and developed countries must make decisions individually and jointly in Durban to fulfill their promises.

David Ciplet is a researcher and PhD student at Brown University, United States. J. Timmons Roberts is director of the Center for Environmental Studies at Brown University. Mizan Khan is professor in the Department of Environmental Science and Management, North South University, Bangladesh. Linlang He is a graduate student and Spencer Fields is an undergraduate student at Brown University. This article is an abbreviated version of their report "Adaptation finance: How can Durban deliver on past promises?". The views expressed in the article do not necessarily reflect those of China Daily.