Senior officials on climate change from Brazil, South Africa, India and China, also known as the BASIC countries, called on developed economies to "do their homework" and offer financial and technology support to developing countries, two weeks before a climate change conference in Warsaw, Poland.

"Finance is key to the success of the Warsaw Conference," read a joint statement issued at the conclusion of the 17th BASIC Ministerial Meeting on Climate Change in Hangzhou on Tuesday.

Su Wei, director of climate change at the National Development and Reform Commission, said officials from the BASIC countries urged developed economies to honor their obligations in a measurable, reportable and verifiable manner, with firm commitments of funding for the period from 2013 to 2020 and a clear roadmap to reach the goal of providing $100 billion per year by 2020.

Global climate finance flows in 2013 have reached a plateau of $359 billion, or around $1 billion per day, which is far below even the most conservative estimates of investment needed, according to a recent report published by Climate Policy Initiative, a climate change NGO based in the United States, on Oct 22.

Developing economies can only realize adaptation, mitigation and technology transfer based on enough financial and technological support, which is why financing is vital, said Xie Zhenhua, China's top climate change official.

The joint statement also emphasized that public financial resources should be the main source of such funding while financing from the private sector should only be supplementary.

"We support the idea to let the private sector invest as long as public financing is still taking the lead," Xie said.

"An important measure to attract the private sector is for developed economies to undertake more ambitious emissions reduction targets, so the private sector can see the market orientation clearly," he said.

The BASIC countries' position is that the effective implementation of deals from previous climate change conferences at Warsaw is paramount for trust building among parties.

"In Warsaw, we will be looking at the level of implementation and the level of how much the developed economies' promises are being fulfilled," said Ambassador Jose Antonio Marcondes de Carvalho, undersecretary-general for Environment, Energy, Science and Technology of the External Relations Ministry of Brazil.

The joint statement also said developed economies should take the lead in combating climate change in accordance with their historical responsibilities and what is required by science.

"The ministers reiterated that the contribution of developing economies to mitigation efforts is far greater than that of developed economies, and noted that the pre-2020 mitigation gap would not have existed if the developed economies had committed to an emissions reduction of 40 percent below their 1990 levels by 2020," it said.

"The developed economies emitted 70 percent of the total greenhouse gases from the Industrial Revolution to 2010, while the developing economies have taken the 70 percent share of emissions reduction targets set globally," Xie said.

Maesela Kekana, chief director in charge of international climate change negotiations and relations of the Environmental Affairs Department of South Africa, and Ravi Shanker Prasad, joint secretary of the Ministry of Environment and Forests of India, also attended the meeting.