Save the world without being an eco-bore

The authors of these two books, Mark Lynas and James Gustave Speth, share a passion for safeguarding the future of this Earth; and both identify reasons why this future is threatened. They are both campaigners and these books set out, in different ways, to convince the reader of their key message: that the signs of global warming are now evident around the world (Lynas) and that the Earth's future can be sustained through citizens' actions (Speth).

On other criteria, however, the books represent very different genres of environmental journalism, from two very different people and targeted at two very different audiences. Although both are successful in communicating their key message, Lynas offers a rather superficial account that merely tugs at the emotions, while Speth's is a profound analysis that engages with mind and soul.

High Tide: News from a Warming World is a clever piece of environmental journalism that is a cross between a rather naive youthful travelogue and an apologetic for the science of climate change as assessed by the United Nation's Intergovernmental Panel on Climate Change (IPCC). Lynas starts his personal search for evidence of global warming during the autumn of 2000 in his own (flooded) backyard in the UK. He visits a flooded pub in York and a flooded housing estate in Monmouth, he talks with (also youthful) scientists and he reads the IPCC reports. But perhaps because he is not convinced by this evidence, either scientific or experiential, or maybe because he thinks that you, the reader, will not be convinced, he embarks on a worldwide trek to see if the evidence is stronger elsewhere. His odyssey takes him to Alaska, Tuvalu in the Pacific, northern China, North Carolina and Peru. In the process, he "blows 20 years of his own personal carbon budget" on air flights and ends up at the International Climate Conference in The Hague in July 2001, when the Bush Administration so dramatically pulled out of the process of the Kyoto Protocol.

What does Lynas conclude from his journey? Well, he is more convinced than ever that climate change is a reality and that its impacts are undeniable.

He also has a wealth of stories to enable him to be "an eco-bore at parties" and he encourages the rest of us to join him in this role. The problem is he cannot fly in a plane until 2020 - OK if he wants to travel to Rome, but not so good for his next book on the Amazon.

The idea behind this book is a good one - to paint the basic scientific conclusions of the IPCC reports about our warming world on to a more colourful and human canvas in the form of a travelogue. But somehow the book is unsatisfying for a number of reasons. The writing style is at times just too corny. The attempts to add substance and colour to what science is telling us often result in melodrama and hype, usually a sign of a weak case. Statements such as "the world is facing climate catastrophe and we all have to change the way we live" or "the impacts described here are just the first whispers of the hurricane of future climate change that is now bearing down on us" did not help to take my thinking to a more challenging level.

The other problem with High Tide is that it becomes too self-conscious and guilt-ridden. Lynas is clearly grappling with his own carbon footprint on the planet, and he never resolves this dilemma satisfactorily. If all of us were to experience Tuvalu in the way he did - "one of those magical places of longing that can never be regained" - we would double the world's carbon emissions. Who has the right to experience such magical places and at what cost to global warming?

While one senses that Lynas is writing for a predominantly UK audience, Red Sky at Morning is aimed at the US market - the "citizens" in the subtitle are certainly not, say, from Rwanda. Speth has 30 years of professional experience in environmental non-governmental organisations, he founded both the World Resources Institute and the Natural Resources Defense Council and he advised Presidents Carter and Clinton.

We get a pacey, well-written account of the status of the world's environment, although the rather routine environmental litany of the first few chapters, and our inability to tackle these problems effectively, breaks no new ground. But this book is not simply a corrective to Bjorn Lomborg's more upbeat account of the state of our environment. In the second half, Speth succeeds in engaging the mind and soul more successfully than Lynas; his years of professional experience in the campaigning world, close to the sources of power, are made to tell. Chapter five is a careful diagnosis of the failings of environmental governance worldwide and chapter six a convincing presentation of ten drivers of environmental deterioration, including the values and ethics of our (or at least US) culture. Globalisation is the focus of special attention. Speth does a good job in presenting the balance sheet of this emergent yet elusive phenomenon, distanced from the optimistic rhetoric of the Group of Eight or the compromised naivety of gap-year students.

But Speth gets even better. In chapter eight, he counters the ten drivers of deterioration with eight transitions to sustainability, including the stabilisation of population, the eradication of mass poverty (with echoes here of Lomborg's "Copenhagen consensus"), the support of benign technologies and the introduction of environmentally honest prices.

Transitions seven and eight - concerning governance and culture and consciousness - receive particular attention. While there are better academic accounts of transition management around, for a popular readership Speth's treatment is excellent and the best starting place.

Citizenship, then, is his final rallying call and, in particular, the recognition that the deepest change of all is needed for planetary survival: a change in the way each of us sees ourselves in relation to the planet. This is about values and self-esteem, about facing our contradictory inner nature and challenging it as only reflective human beings can. The ultimate transition to sustainability has to be an inner one, from which all else flows.

My only disagreement with Speth is whether it is the US that holds the key to the Earth's future. The book implicitly seems to think so, but one suspects that the 21st century will not only see further critical transformation of the Earth's sustaining powers but also surprising shifts in the balance of geopolitical power. Who is writing about the red skies over China, India and Russia? I hope it is not Lynas.

Mike Hulme is executive director, Tyndall Centre, University of East Anglia.