in overall fish catch. This is a matter of life and death for the over 1 billion mainly poor people who are dependent on fish for their primary source of protein, and whose coastal fisheries have often been scoured out by foreign trawlers from rich nations whose own seas are exhausted.
But voluntary measures will only achieve so much. For biodiversity protection to really work, and for the funds to flow, it needs to be given the force of law. Here too recent progress gives cause for some qualified optimism. The Convention on Biological Diversity, long the poor relation of the Convention on Climate Change, enjoyed a boost in October 2010 with the agreement by world governments of a ‘Strategic Plan’ for the decade to 2020, intriguingly subtitled ‘Living in harmony with nature’. The Plan directs governments to mainstream biodiversity concerns ‘throughout government and society’, and to take ‘direct action … to restore biodiversity and ecosystem services’ by ‘means of protected areas, habitat restoration, species recovery programmes and other targeted conservation interventions’.58 These requests are still voluntary at the international level, but national governments are encouraged to turn them into law to ensure that companies, individuals and institutions take biodiversity seriously.
Perhaps just as importantly, a new scientific body is being established, aiming to provide the same expert advice on biodiversity as the IPCC does on climate change. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) could help finally put this issue at the top of the international scientific and policy agenda, compiling data and producing landmark reports that can inform the efforts of governments and other policymakers.
Biodiversity is an issue whose time has come. All we need to do now is figure out how to pay for it. Remember, all it will cost to save the tiger from extinction is a mere $82 million a year. Rather than passively lamenting its demise, we need to roll up our sleeves and start raising funds. If you do only one thing after reading this chapter, join this effort today.
Chapter Three
The Climate Change Boundary
That climate change is a planetary boundary will come as a surprise to no one. What may come as a surprise however is that the target that has been advocated by not just governments, but environmentalists too, has for years been much too weak. More recently that has begun to change: now an extraordinary coalition of more than a hundred governments and dozens of campaigning groups is lining up squarely behind a safe target for carbon dioxide in the atmosphere, as proposed by the planetary boundaries expert group. Although powerful countries like the US and China are a long way from endorsing this target – and the world economy is even further away from meeting it – the fact that such a crucial planetary boundary has attracted such a strong level of support is a serious piece of good news and one that deserves celebration.
Previous chapters explained how humanity has risen to global prominence through a massive exploitation of fossil energy resources. Human civilisation remains over 80 per cent dependent on fossil fuels worldwide, and as the economy grows so does the rate at which the carbon dioxide resulting from the burning of coal, oil and gas accumulates in the air. On average the carbon dioxide concentration of the atmosphere rises by about 2 parts per million (ppm) every year, from a pre-industrial level of 278 ppm to about 390 ppm today. Whilst the precise level of temperature rise implied by higher CO2 is always going to be uncertain, it is indisputable that – all other things being equal – global warming will result from the human emission of billions of tonnes of greenhouse gases, sustained over more than a century.
Arguments over what would be a ‘safe’ level of atmospheric CO2 have raged for decades. Back in 1992 the UN Framework Convention on Climate Change required in its much-cited Article 2 that the objective of international policy should be to avoid ‘dangerous anthropogenic interference’ in the climate system – but without defining what ‘dangerous’ actually meant. The British government’s Stern Review on the Economics of Climate Change of 2006 suggested a stabilisation target of 550 ppm CO2e (carbon dioxide-equivalent, implying a bundling together of all climate-changing gases rather than only CO2). Two years earlier, the European Union had endorsed a target of limiting temperature rises to 2 degrees Celsius, implying – it was stated – a CO2 target of 450 ppm. This latter objective was endorsed in my 2007 book about climate-change impacts, Six Degrees, where I suggested that 2 degrees and 450 ppm were necessary to steer away from large-scale dangerous tipping points in the climate system. Major environmental groups also lined up behind similar targets, and pushed them hard at international meetings.
It turns out we were all wrong. A fair reading of the science today, as this chapter will show, points strongly towards a climate change planetary boundary of not 450 ppm but 350 ppm for carbon dioxide concentrations – a level that was passed back in 1988, the year that NASA climate scientist and planetary boundaries expert group member James Hansen first testified to the US Congress that global warming was both real and already under way. Hansen has done more than any other scientist to put the 350 number on the map. He was one of the first to realise its importance, and has become a tireless advocate of the actions that are necessary to meet it. It was Hansen’s discussions with the American author and activist Bill McKibben, indeed, that led to the creation of the worldwide movement 350.org. McKibben calls 350 ‘the most important number in the world’, and he is right.
Never mind the enduring global-warming controversies in the media; these are a distraction. The climate change planetary boundary is the one that is best understood, and that we know most about how to achieve. Moreover, meeting the boundary is a basic requirement for any level of sustainable planetary management: if CO2 continues to rise, and temperatures begin to race out of control, then the biodiversity boundary, the ozone boundary, the freshwater boundary, the land use boundary and ocean acidification boundaries cannot be met either, and the remaining planetary boundaries are also called into question.
The climate boundary is humanity’s first and biggest test that will reveal early on whether we are truly capable of managing our environmental impacts in a way that protects the capacity of the biosphere to continue to operate as a self-regulating system. It is a testament to our intelligence that we have developed our scientific understanding so far that we now know a great deal about how the climate system works, and can define with some confidence where the planetary boundary should lie. It is perhaps testament to our stupidity, however, that despite decades of research and advocacy on climate, all pointing at the need to control greenhouse gas production, human emissions today continue inexorably to rise.
Thankfully the technologies and strategies that humanity needs to achieve the climate boundary are today no mystery. We have all the tools necessary to begin a wide-scale decarbonisation of the global economy, and to achieve this at the same time as both living standards and population numbers are rising rapidly in the developing world. But environmentalism will need to change at the same time. Much of what environmentalists are calling for will either not help much or is actually thwarting progress towards solving climate change. It is time for a new – and far more pragmatic – approach, that does not hold climate change hostage to a rigid ideology.
350: CURRENT EVIDENCE
First we need to establish whether 350 is actually the right number, and one that is supported by science. There are three broad lines of evidence that support the conclusion that atmospheric CO2 concentrations need to be limited to 350 ppm. The first is the sheer rapidity of changes already under way in the Earth system, changes I never dreamt I would see so quickly when I started working on this subject more than ten years ago. These warn of looming danger. The second is modelling work suggesting that positive feedbacks – or thresholds, or tipping points, call them what you like – are getting perilously close. The third, and perhaps most conclusive, is evidence from the distant past linking temperatures with carbon dioxide concentrations in earlier geological epochs.
The best place to look for confirmation that our planet is gaining heat is not the air temperature at the ground, but the energy imbalance – the difference between incoming and outgoing radiation – at the very top of the atmosphere. There our sentinel machines, the satellites silently orbiting the planet twenty-four hours a day, show clearly that