The rich world's leaders are preparing for the G8 summit in Russia's second city of St Petersburg on 15-17 July 2006. At the 2005 summit in Gleneagles, Scotland, Britain's prime minister Tony Blair highlighted climate change and Africa as the two most important issues for the heads of state and government to discuss. A year on, the top item on the summit agenda is energy, but from a security rather than climate-change perspective. The sense of a retreat is palpable.

At Gleneagles, Tony Blair also invited five heads of state – from China, India, Brazil, Mexico and South Africa – for a "G8+5" dialogue on climate change. This produced a "Gleneagles plan of action" which was, in turn, given to the president of the World Bank, Paul Wolfowitz, to take forward and report back to the 2008 G8 meeting, to be held in Japan.

Camilla Toulmin is the director of the International Institute for Environment & Development (IIED), a policy-research NGO based in London. An economist by training, she has worked in the drylands of Africa on land, agriculture and livelihood systems.

Also by Camilla Toulmin in openDemocracy:

"Africa: make climate change history"
(May 2005)

"The G8 and climate change: a campaigners’ scorecard" (July 2005) – with Saleemul Huq

"Why Montreal matters" (December 2005)

"Montreal scorecard: Kyoto 157, United States 1" (December 2005)

In the meantime, the World Bank has prepared an Energy Investment Framework (EIF) paper for consultation which outlines a short-term - and longer-term - strategy that includes both mitigation (linked to investments in energy) and adaptation (linked to investments in development). It is not yet clear whether the G8 summit to be hosted by Germany in 2007 will consider these issues as well.

The challenges of addressing climate change gains importance day by day, as more and more evidence comes to light from scientists recording its impacts across the world – from the Arctic to the tropics, from droughts and floods to hurricanes. This incontestable reality, echoed in increasing public and media awareness, is daily confirming climate change to be an issue of global importance that no politician or citizen can afford to ignore.

Meanwhile, the keenly-awaited report of the Stern review on the economics of climate change – commissioned by Britain's chancellor of the exchequer Gordon Brown – is due in the autumn. This will help fuel debate on how to move more quickly to a low-carbon economy at the next conference of the parties to the climate-change convention, to be held in Nairobi on 6-17 November 2006.

At St Petersburg, the leaders of the G8+5 need to recognise that their actions have so far been woefully small in relation to the scale of the problem. This global issue cannot be left to the leaders of a handful of countries to decide behind closed doors, however powerful or populous they may be. It must involve citizens and civil-society groups from countries around the world.

Climate change is a truly global problem, one in which every single human being on the planet is implicated. By the same token, every human being can be part of the solution, by attending to his or her carbon footprint that measures the effect on the environment of an individual's behaviour. The imbalance in the production of greenhouse-gas emissions means that this footprint tends to be very large for rich people and for the comfortable majority in the wealthiest countries, even as the impacts of climate change fall disproportionately on the poorest people and countries whose contribution to carbon emissions is by comparison miniscule.

Thus, the issue is no longer one of preventing a global environmental problem by cutting CO2 emissions, or of providing more development assistance to poor countries for adaptation. Rather it is one of global justice, which must be addressed on a global scale. As global as well as national citizens, everyone has a responsibility to take stock of our carbon footprint and take measures to reduce it.

Saleemul Huq is the director of the Climate Change Programme at the International Institute for Environment and Development (IIED).

Also by Saleemul Huq in openDemocracy:

"The clean cabs of Dhaka" (May 2005) – with Ijaz Hossain

"The G8 and climate change: a campaigners’ scorecard" (July 2005) – with Camilla Toulmin

The 2006 G8 summit's focus on energy security and geopolitical issues such as Iran and North Korea must not be allowed to eclipse the deep, long-term question that climate change raises: the very survivability and sustainability of life on the planet. The summit leaders have an obligation to the world's citizens to summon their courage and adopt policies that can prevent the most severe consequences of climate change. These consequences are still – just – avoidable, but only if action starts now.

Such action will have to include much more stringent targets for emission reductions beyond 2012, when the first commitment period of the Kyoto protocol ends. The world – especially the rich, developed countries that produce the highest greenhouse-gas emissions – needs to shift to a much lower carbon economy. This requires investment in new technology, infrastructure and institutions. The transformation will carry great benefits as well as costs: although the focus of public discussion is often on the costs of such investment, there are also opportunities to be gained, particularly for those companies and countries taking an early lead.

The attention to mitigation also needs a parallel track in the form of assistance to poor people and poor countries to adapt to the unavoidable impacts of climate change in the near term. Rich countries are the ones who created the problem, so it's the rich who have a moral duty to bear the costs of cleaning it up. The G8 summitteers in St Petersburg have a duty to lead – by listening, acting, and persuading – on this most critical issue of our time.