This week in Bali the world begins the complex task of forging a global consensus towards a comprehensive and fair post 2012 climate change framework. Urgent and ambitious action is needed to stabilize and reduce our greenhouse gas emissions. The failure to reduce our impact on the environment could have devastating consequences, not only for the environment but also for our economies.

Why is climate change a trade and investment challenge? Because the technology that helps us drive down green house gas emissions is traded like any other. The skills and expertise to tackle climate change can be exported.

Emission reductions needed to meet this challenge cannot be achieved without uptake of green goods and green services. Any global attempt to tackle climate change will have to be supported by the development and deployment of green technologies as quickly and cheaply as possible to every part of the global economy, as highlighted by the recent report of the UNFCCC (United Nations Framework Convention on Climate Change) on investment and financial flows to address climate change. Transferring the technology needed to tackle climate change to developing countries in particular is crucial.

In this context, trade, among other supportive and enabling policies, has a role to play in fostering the dissemination of clean technologies and services, and thereby contribute for its part to addressing the challenge ahead of us.

Last week at the WTO in Geneva the United States and Europe tabled a new proposal for an agreement on trade in environmental goods to be part of the final package of the Doha world trade talks. They will be taking the same proposal to World trade Ministers when they meet in Bali this weekend.

As a first step, the first part of the proposal would see tariffs in a list of key climate change mitigation technologies reduced immediately to zero wherever possible. For the purpose of selecting these technologies, it is suggested to build on a list recently drawn up by the World Bank for instance covering solar panels, solar-driven boilers and wind turbines. As well as cutting tariffs for these goods, WTO members would agree to seek removal of certain restrictive national rules on trade in them.

The second part of the proposal is for a broader Environmental Goods and Services Agreement (EGSA) that would go beyond these key climate relevant technologies and also include other technologies, such as those linked to basic sanitation - waste and waste water management and air pollution reduction systems.

The EGSA would also offer a chance for countries who wished to participate to liberalise trade in services sectors that contribute to their ability to tackle climate change such as waste management, architecture and energy-efficient construction. The OECD estimates that these vital skills make up more than half of the current market for green trade.

When we restrict trade in these goods and services we stop valuable skills and experience flowing from one part of the global economy to another. The World Bank estimates that liberalisation of trade in climate-friendly technologies could see this trade increase by up to 15% a year - more than twice the current growth for global merchandise trade as a whole. Tariffs and restrictions on this trade act as taxes on those trying to green their business, produce environmentally friendly products or reduce the emissions of their industry.

In 2001 WTO Members agreed that the Doha Round should include a special attempt to remove barriers to trade in environmental goods and services. While the core areas of the Doha negotiation have moved gradually forward, this part of the negotiation has faltered. Given the compelling benefits and the urgency of the global warming challenge, it is time to revive it.

All WTO Members have an interest in such an agreement. If we are to achieve significant emissions reductions, we all need the technologies, and we all need them at the most competitive price. Although the EU and the US are market leaders in many parts of the environmental goods and services sector, the emerging economies also have a growing stake in this trade. Indian exports of energy-saving water heaters have grown five fold in the last few years. Chinese wind-powered electricity generators are increasingly being traded with Africa. One of the world's leading water management companies is Brazilian, and cut its teeth working with businesses in Sao Paolo.

To truly fulfil its potential, a bold initiative on environmental goods and services should help green technology and skills flow between developed and developing countries and between the economies of the developing world.

Given the shared global responsibility to tackle climate change, is there any longer an argument against a more open global market in environmental goods and services? We believe there is not. The UN Framework Convention on Climate Change Conference of the Parties in Bali must agree on the launch of a negotiating process aimed at agreeing on a comprehensive and fair post 2012 climate change agreement by 2009. Enhancing cooperation, development and dissemination of clean technologies will be a key component of these negotiations.

An open global market in trade in green goods and services should be part of that.

* The writers are US Trade Representative and EU Trade Commissioner