– John Reid MP, formerly UK Home Secretary and Secretary of State for Defence, is the Chairman of the Institute for Security and Resilience Studies at University College, London. The opinions expressed are his own. -Barack Obama’s announcement that there will be no all-encompassing protocol agreed at Copenhagen underlines that climate change is perhaps the most complex issue facing the world today. In part, this is because it involves long-term thinking and modeling which our existing political, financial and economic institutions and governance frameworks are ill-designed and configured to grapple with and resolve.With uncertainty building over what, if anything, the Copenhagen Summit can still achieve, now is therefore the time to remind ourselves about some of the larger stakes in play next month at what has been billed by some as the most important environmental summit in world history.We know already that climate change will impact upon our quality of life and have potentially profound consequences for future generations through, for instance, the impact of rising sea levels, and more extreme weather. In the medium-term, the Stern Review estimates the overall impact on GDP could be 5 to 20 percent from 2050.This alone should alarm us all.Moreover, while all will be affected, it is the most vulnerable countries and populations which will suffer earliest and most — even though they have contributed least to the causes of the problem. This is injustice on a truly global scale and should, in itself, be sufficient reason for all sides to move closer at Copenhagen so that a comprehensive climate change deal can be agreed in 2010 or 2011.However, there is an additional factor in this equation that should compel our action out of enlightened self-interest. Because climate change also has major geopolitical and security implications for the UK, the EU and the rest of the world.Indeed, my own view is that environmental security will be at the heart of everything that UK Governments will do for years to come — both because of the huge economic costs if we fail to act, and the immense potential for conflict over resources becoming the dominant source of global insecurity — not least because of the resultant population movement.Water provides a potential harbinger of things to come. It was Mark Twain I believe who declared that while “whisky is for drinking, water is for fighting over”. Sadly, the blunt truth is that lack of water and agricultural land is already proving a significant contributory factor in conflicts like that in Darfur.It is estimated that more than 300 million people in Africa currently lack access to safe water. Most countries in the Middle East can also be classified as having water scarcity.This problem is only likely to grow, right across the world, as a result of climate change. It has been estimated, for instance, that by 2025 some 1.8 billion people will live in countries or regions with absolute water scarcity.The reason why we so urgently need a new climate change deal is that there are limits to what individuals and single states can do to tackle climate change. The UK’s annual carbon emissions account for “only” 2 percent of the global total and even if we were to eliminate emissions completely the annual growth in emissions elsewhere in the world would exceed the savings in approximately 18 months.However, this is not an excuse for inaction: we cannot ask countries such as China and India to sign up to a new climate change deal unless we also get our own “house in order”. After all, the West has been the primary beneficiary of globalisation for many years: it must now face up to the obligations which globalisation confers.Our task should be to harness these challenges, converting insecurity into opportunity. In other words, to help guide the world through the issue arising from ever increasing global interdependence and through common action and endeavour translate today’s problems into tomorrow’s action and enterprise.The EU carbon trading emissions system is a classic example here. Imperfect it may be, but as the first and most ambitious initiative of its kind anywhere in the world, it shows that supra-national action in the environmental sphere is possible and desirable.At Copenhagen, Europe has an opportunity to cement this commitment to a sustainable future so that we can fortify our credentials as the global leader in the low carbon economy. At a time of major financial stress, this also has the potential to create hundreds of thousands of European jobs and billions of pounds of growth to ensure that environmental industries are amongst the fastest growing sectors in our economy.While securing a new climate change deal looks increasingly tough, the issue of water scarcity itself underlines that there are reasons for optimism in major trans-boundary environmental issues. From the Indus to the Jordan and the Mekong Rivers, numerous states in political and even military conflict, in some of the most difficult of political environments, have found innovative and cooperative solutions to water management tensions.So that is the challenge we confront: we can no longer afford to see climate change just as an issue of impact on the environment. We must all face up to the larger consequences, including the geopolitical dimensions, and be prepared to take the necessary action and have the long-term horizons to convert the insecurities of today into the opportunities of tomorrow.The goal must be nothing less that ensuring that government, business and society can not only be resilient to, but flourish, in the increasingly uncertain times in which we live.