he fact is that all the projections in the latest assessment by the Intergovernmental Panel on Climate Change - the IPCC – show that, later this century, global warming will exceed the danger level of 2 degrees Celsius above the pre-industrial temperature unless worldwide emissions of greenhouse gases are cut deeply.

In the IPCC’s worst-case scenario, without firm action climate change could reach dangerous levels as early as 2050 - in other words, within the lifetimes of well over a billion young people alive today. A growing body of scientific evidence since the IPCC published its report two years ago suggests this worst-case scenario is on the way to being realised - or even exceeded.

The window of opportunity for avoiding dangerous climate change is closing fast. Two degrees Celsius above pre-industrial levels translates into around 1.2 degrees above today’s temperature. Some studies indicate that past emissions mean a further 1 degree rise is already likely. That means the Copenhagen agreement is almost certainly the world’s last chance to put global emissions onto a trajectory that can keep us out of the danger zone.

We know that failure to prevent dangerous climate change will cost far more than taking the necessary action – between 5% and a staggering 20% or more of global annual GDP in the long run, according to Lord Stern’s seminal study. Delay will only increase the cost and decrease the chances of success.

Moreover, far from being a reason to neglect the fight against climate change the economic recession – and the stimulus measures needed to counter it – have turned out to be a golden opportunity to accelerate investment in building the low-carbon economy that is needed to bring climate change under control.

The European Economic Recovery Plan and the similar initiatives taken in countries such as the US, China and South Korea have been designed to boost the economy through investment in energy efficient technologies and renewable energy that will create lower-carbon growth and green jobs.

This fully reflects the vision of the integrated climate and energy strategy set out by the European Council. Recognising the benefits that the EU stands to gain by moving first, the European Council in March 2007 committed to the so-called ‘20-20-20’ targets and to transforming Europe into a highly energy-efficient, low-emission economy.

This is the vision that is now being implemented through the climate and energy package that became law last month and through the programme of more demanding energy efficiency standards that the Commission is progressively putting into place.

Through these measures we are strengthening the EU’s energy security and giving a massive boost to the low-carbon technologies of the future and to the creation of green jobs. In the context of the negotiations on a new global climate agreement, our measures have sent a crucial signal of the EU’s leadership and determination to get a strong outcome in Copenhagen.

By 2020 our emissions will be 20% lower than in 1990 and we will be getting 20% of our energy from renewable resources. The aim is also to reduce the EU’s energy intensity by 20% and to bring carbon capture and storage technology into the mainstream within the same timeframe. No other part of the world has such ambitious targets and the measures in place to meet them.

But our vision of climate policy must also include finding ways to strengthen the resilience of all sectors of the economy against the climate change that is inevitable. From more frequent extreme weather to the retreat of glaciers around the world, climate change is already making itself felt and all the projections indicate it will continue to become more severe for several decades ahead, however successful we are in cutting emissions.

There is no doubt that reaching agreement in Copenhagen is a huge challenge and there remains an enormous amount of work to do, but I am optimistic that we will succeed. The warnings that science is giving us quite simply mean we cannot afford to fail, and I believe this sentiment is widely shared in the international community even though today positions are still far apart on many issues.

Moreover, the international re-engagement of the United States under President Obama and its determination to put in place domestic climate legislation mark a sea change that has greatly improved the prospects for success in Copenhagen, even if the new administration still needs time to develop its positions.

This more positive mood was a leitmotif at the three major international climate meetings held last month: the UN talks in Bonn, the G8 environment ministerial in Siracusa and the first meeting of the Major Economies Forum in Washington last week.

The European Union has been developing its position on post-2012 action since as far back as 2005. Over the first quarter of this year, with endorsement from several formations of the Council as well as the European Council in March, we have articulated a comprehensive and detailed vision for the Copenhagen agreement on the basis of the Commission’s ‘Copenhagen communication’ of 28 January.

Firstly, developed countries as a group must take the lead in reducing emissions by committing to a collective emissions cut of 30% below 1990 levels by 2020. As you will know, the EU is committed to increasing our emissions reduction from 20% to 30% if other countries agree in Copenhagen to do their fair share.

This collective reduction by the developed world should be shared out fairly and requires comparable levels of effort based on countries’ capability and responsibility. We have proposed a balanced set of criteria against which the comparability of national targets can be measured.

In this context, Australia's decision earlier this week to scale up its emissions reduction target to 25% below 2000 levels if other developed and developing countries agree to take strong action in Copenhagen is a very encouraging development. I urge other developed country Parties to take another look at their own targets and to consider increasing their level of ambition so that our collective efforts will add up to the 30% reduction that is needed. The offers on the table so far risk falling short.

Secondly, even if the developed world cuts its emissions to zero we will lose the battle against climate change unless developing countries - and particularly the major emerging economies – also mitigate their rapid emissions growth. This was [implicitly] recognised in the Bali Action Plan when developing countries agreed to take ‘nationally appropriate mitigation actions.’

The latest scientific evidence indicates that for global emissions to peak by 2020 - as they must if we are to get them onto the right track to stay below 2 degrees - developing countries’ collective emissions will need to be some 15 to 30% below business as usual levels in 2020. Let me stress that this lower emissions growth will still enable developing countries to continue growing their economies rapidly.

We propose that developing countries should draw up and implement national low carbon development strategies setting out mitigation actions for each key emitting sector. This is an idea which was generally well received at the Bonn meeting last month.

The low carbon development strategies would identify the actions to limit emissions that can be implemented using domestic resources and those for which external financial and technical support would be needed. A mechanism to be established under the UN climate convention would then assess the adequacy of these actions and match up the identified needs with the necessary international support.

The third key element is finance. It is no exaggeration to say that this is the issue that will make or break the Copenhagen agreement. The developed world will have to substantially scale up its financial and technological support to help developing countries address both the mitigation of emissions and adaptation to climate change.

As EU leaders made clear at the European Council in March, the European Union is committed to taking on its fair share of this funding. We believe it should come from a mix of public and private sources, including an expanded international carbon market.

Within the EU we are actively considering two of the options on the table for generating additional public financing at international level, the Mexican proposal and the Norwegian proposal. Both have their pros and cons. It is a difficult debate that is not made easier by the financial and economic crisis, but we are committed to settling our position well in advance of Copenhagen.

Fourth and finally is the need for a global carbon market. This is essential for achieving at least cost the deep global emission cuts that are required.

The carbon market can also be a major source of the additional financing needed. Under the climate and energy package, Member States have agreed that at least half of the revenues from the auctioning of emission allowances in the EU should be used to combat climate change, both at home and abroad.

Our vision is that all developed countries should have domestic cap-and-trade systems in place by 2013 and that these should be linked up to form an OECD-wide carbon market by 2015. The discussions now under way on setting up a US federal cap-and-trade system are very encouraging and hold out the potential that a transatlantic carbon market could become the engine room of an evolving global system. As with our Emissions Trading Scheme, the design of domestic company-level trading systems should remain a matter for governments and should not be subject to the UN negotiations.

We also want to see the Clean Development Mechanism substantially reformed so that it credits only those projects that deliver real additional reductions and that go beyond low cost options. Moreover, for highly competitive sectors in the big emerging economies the CDM should be phased out and replaced by a sectoral crediting mechanism that would generate credits once a whole sector does better than an agreed emissions benchmark. We believe carbon crediting mechanisms could contribute one third or more of the additional investment needed to mitigate emissions in developing countries. The sectoral crediting mechanism we propose should pave the way for developing countries to introduce cap and trade systems of their own from around 2020.

At the Bonn meeting last month talks finally moved into full negotiation mode, and at the June session comprehensive draft negotiating texts will at last be on the table. But even with the two extra sessions that have been agreed there are still only six weeks of face-to face negotiating time left before Copenhagen.

That means we must also take full advantage of the opportunities for finding common ground offered by parallel processes, such as the G8 and Major Economies Forum summits in July and the climate summit that will be held in connection with the UN General Assembly meeting in September.