It is often said by perceptive observers that a disconnect is in evidence in many countries between a public that want stringent action to tackle climate change and what governments are actually doing.

The United States, for example - which for many years has had no forward-looking policies in reducing emissions of greenhouse gases (GHGs) - is still encumbered with a large number of senators unwilling to act on account of partisanship or scepticism about the science of climate change.

It is a well-known fact that powerful vested interests and those opposed to action on climate change are working overtime to see that they can stall action for as long as possible.

The Centre for Public Integrity in the US has found that some 770 companies and interest groups have hired an estimated 2,340 lobbyists to influence America's federal policies on climate change in the past year, just as the stakes became higher with the prospect of far-reaching climate legislation in the US. That translates into more than four lobbyists for each member of Congress in Washington DC.

The climate sceptics have also been active in other ways. Take the hacking of emails from the University of East Anglia and the use of private communications between the scientists involved to discredit the science contained in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), which I chair. These scientists are highly reputed professionals, whose contributions over the years to scientific knowledge are unquestionable.

But, more importantly, even the allegations made on the basis of the stolen emails have proved incorrect. The papers which were criticised in the emails were actually discussed in detail in chapter six of the Working Group I report of the AR4. Furthermore, articles from the journal Climate Research, which was also decried in the emails, have been cited 47 times in the Working Group I report. It is also a well-established fact that the IPCC relies on datasets - not from any single source - but from a number of institutions in different parts of the world. Significantly, the datasets from East Anglia were totally consistent with those from other institutions, on the basis of which far-reaching and meaningful conclusions were reached in the AR4.

The same group of climate deniers who have been active across the Atlantic have now joined hands to attack me personally, alleging business interests on my part which are supposedly benefiting me as well as the Indian Tata group of companies. My institute, The Energy and Resources Institute (TERI), has no links with the Tata group, other than having been established through seed funding from that group as a non-profit registered society in 1974, much like several other non-profit institutions of excellence set up by the Tatas for the larger public good. As for pecuniary benefits from advice that I may be rendering to profit making organisations, these payments are all made directly to my institute, without a single penny being received by me.

I am providing this background only to highlight the fact that powerful vested interests are perhaps likely to get overactive in the coming months, and would perhaps do everything in their power to impede progress towards a binding agreement that is hoped for by the end of 2010 in the next major climate negotiations in Mexico City. In the end, knowledge and science will undoubtedly triumph, but delay in reducing emissions of greenhouse gases would only lead to worse impacts of climate change and growing hardship for the most vulnerable regions in the world, which are also unfortunately some of the poorest communities on earth.

A multilateral agreement to tackle climate change is absolutely essential, but given the slow pace of progress and the power that vested interests exercise over legislative and policy initiatives in democratic societies, something more may be essential. Firstly, given the critical role of the United States in forging an effective agreement to meet the challenge, the passage of legislation in that country will have to be supplemented with several initiatives to be put in place by the executive branch of the government.

But importantly, it seems to me that civil society and grassroots action would have to come into their own, not only to ensure that human society takes responsibility for action at the most basic level, but also to create upward pressure on governments to act decisively. If such grassroots efforts do not spread and intensify, nation states may not be able to resolve the differences that exist between them.

It is becoming increasingly clear that the spread of knowledge and awareness would be a critical driver of the transformation that is required to move human society towards a pattern of sustainable development. This would also be the most effective means of thwarting the efforts of skeptics and vested interests, who will do everything possible to maintain the status quo. As the science in the IPCC Fourth Assessment report clearly demonstrates, there is no leeway for delay or denial any longer.

• Rajendra Pachauri chairs the Intergovernmental Panel on Climate Change (IPCC) and is director-general of The Energy & Resources Institute