Britain's new coalition government has agreed to go ahead with a replacement for Trident. This overrides the position taken by the Liberal Democrats before the election. They were the only one of the three largest parties to oppose a rush to renewal.
Greenpeace's campaign was framed for the run-up to the election so my message comes after the horse has bolted. I hope, however, that they and others will continue their opposition to this misguided, dangerous and costly policy.
I wrote a short backgrounder for the thirty-seconder and post it below. Even this, of course, simplifies many key issues. For an introduction to Marine Protected Areas you could hardly do better than Enric Sala's talk recently posted by TED. Callum Roberts of York University has also written about this brilliantly. And for a little more context on destruction of the seas, Jeremy Jackson TED talk is also good. Anyway, here's my spiel:
Trident is a weapon system of the Cold War, designed for the world of Mutually Assured Destruction or MAD.  But that’s not the world we live in today. We are moving into a multipolar world in which many, perhaps dozens, of emerging powers will have nuclear weapons and the means to deliver them over long distances, and in which non-state actors may be able to explode a nuclear device in a major city. This is a world of significant and increasing risks. None of them will be reduced by British possession of weapons designed for the mass slaughter of innocent people.
The best way to tackle our present nightmare is through international cooperation that leads to more effective control of nuclear materials in the civil sector, and to better control, limitation and, ultimately, abolition of nuclear weapons.  The framework for this, imperfect as it is, already exists. It’s called the Non-Proliferation Treaty and the overwhelming majority of nations, including Britain, are committed to it. Under its terms, the five officially recognized nuclear powers of which Britain is one are required to move towards nuclear disarmament. In return, other countries give up their programmes. After nearly a decade of neglect by the Bush administration in the United States, the administration of Barack Obama has breathed new life into this process. And there has never been a better opportunity for Britain to help reduce threats to its own security as well as the rest of the world.
A small part of the money earmarked for a new generation of British nuclear weapons could make a real difference here. 100 million pounds -- just over one tenth of one percent of 97 billion -- could promote sustained, creative engagement with and between other powers: trust-building exercises, exchanges of expertise - especially where trust is least - help for the creation of nuclear weapon-free regions and so on.
If we’re serious about our future security and well-being we should also consider other priorities. How an additional ten billion for education, for scientific research and development, and for greater energy efficiency? Hey, we could even use some of the money to reduce the government deficit.Footnotes
And here’s another idea: the protection of endangered species and vulnerable ecosystems worldwide. As a writer on the natural world, I have found that people are only beginning to understand the wonders and the true value of this, our common heritage, and that we destroy it at our peril. But as we breath species and ecosystems are probably being destroyed faster than at any time in human history and perhaps for tens of millions of years.
The challenges of ecosystem protection and restoration are huge and complex. Many of them cannot be solved or even mitigated by throwing money at them. But a few can. And in this, the International Year of Biodiversity, Britain can make a difference where it matters most. One of the best ideas around is the creation of new Marine Protected Areas, or MPAs. These can do more than anything else to stem the destruction of the ocean life, at least in the near term. Relatively tiny sums - just one or two million a year for the Chagos Archipelago, for example -- have helped ensure some of the world’s most extraordinary coral reefs have a good chance of getting through the next few decades. A worldwide network of MPAs, increasing coverage from under one percent of the oceans to as much as a fifth or even third, is achievable for globally trivial sums, and it can be done in ways that recognize the needs of local people. Unlike the enormous subsidies currently paid to the fishing industry, it would actually deliver a positive return on investment. Similar initiatives to protect biodiversity on land can work too. A billion pounds from Britain would be a good start.
 According to Aron Bernstien of the Council for a Livable World, 192 independently targeted warheads on a Trident submarine can deliver 100 to 300 KT (The Hiroshima bomb was 15KT). This means that they can deliver, on a conservative estimate, 19 MT or more than six times all of Allied ordnance deployed against Germany, Japan and other powers in World War Two: " It's reported that UK Trident submarines carry 48 warheads.
 See, for example, A World Free of Nuclear Weapons by George P. Shultz, William J. Perry, Henry A. Kissinger and Sam Nunn. The Wall Street Journal, January 4, 2007.
P.S. Martin Rees on Disarmament Labs