Climate Safety Report - 300 ppm

Why humanity must aim for 300 ppm to restore a safe climate - this report is a summary of the latest climate science and solutions and argues convincingly that humanity must reduce atmospheric carbon levels to 300 ppm or below to restore a safe climate.

Science

Following the record 2007 melt in Arctic summer sea ice extent, 2008 saw a record low in sea ice volume. Arctic climate scientists are now predicting an Arctic oceanice-free in summer by 2011-2015, eighty years ahead of predictions made by the Intergovernmental Panel on Climate Change (IPCC). Contrary to what the media coverage suggests, the significance of an earlier-than predicted Arctic melt extends beyond displaced polar bears and easier access to oil and gas.

An early Arctic melt will cause additional heating, as a shrinking ice cap reflects less sunlight into space; additional greenhouse gas emissions, as the ensuing regional warming melts frozen permafrost; and additional sea level rise, as the Greenland ice-sheet comes under increased temperature stress.

Furthermore, the Arctic melt is taking place in the context of faster change in the climate than the IPCC have predicted. It is clear that the IPCC's predictions of future sea-level rises are underestimates. Potential predicted sea level rises would put us in the region of impacts orders of magnitude greater than any we have seen to date. Carbon sinks - which provide the Earth's natural capacity to draw carbon out of the atmosphere - are degrading as temperatures rise and ecosystems are destroyed. The Earth's sinks have up to this point absorbed almost half of all man-made emissions - we may not be able to rely on them to do so in the future. Ecosystems, already under pressure from human activity, are proving more vulnerable to temperature rise than anticipated.

Change is happening ahead of schedule. This suggests that the climate is more sensitive that we thought - demonstrating that although the overall direction of climate change is very clear, there are still significant uncertainties about its speed, and details of specific regional impacts.

Targets

Statements about targets for emissions reductions inevitably simplify real-world complexity. However useful it might be politically to state that a particular level of cuts in emissions will lead to a particular atmospheric concentration of greenhouse gases, which will deliver a particular temperature rise, it is not helpful in gaining a true appreciation of the actual uncertainties involved. The challenge is to draw sophisticated and powerful conclusions about the targets we should set based on a set of very disparate information about the impacts of climate change. One valid way to make generalisations is to examine the concept of "climate sensitivity" - the tool used for converting atmospheric concentrations of CO2into temperature rise.

The higher climate sensitivity is, the more the climate changes in response to greenhouse gases. The IPCC estimate a range of values for climate sensitivity - from low to high, with a mid-range "best estimate". Their scenario modelling work is based on this "best estimate" figure. They note that policymakers, to reduce the risk of impacts, may want to take the higher end of the range for setting policy. However, assuming a higher figure means that none of their suggested scenarios for emissions reductions limit temperature rise to below two degrees. Furthermore, the upper end of the range of climate sensitivity may be even higher than that suggested by the IPCC.

The observed impacts of climate change suggest that the climate is more sensitive than thought. The higher sensitivity is, the lower the targets we need to set to meet a particular temperature rise. This should suggest that we set lower targets as a very basic precautionary principle. If climate sensitivity is higher we may already be past the atmospheric concentration which will ultimately deliver 2 degrees of temperature rise.

As a society we are preparing for a medium-sized climate problem, despite evidence that points to the problem being greater than we had anticipated. Instead of relying of an illusion of certainty, we need to manage the risks of climate change responsibly. This means reducing atmospheric concentrations to within the range that we know the climate will maintain stability - 300 ppmv CO2 equivalent. This would rule out a domino effect of sea-ice loss, albedo flip, a warmer Arctic, a disintegrating Greenland ice sheet, more melting permafrost, and knock-on effects of massively increased greenhouse gas emissions, rising atmospheric concentrations and accelerated global warming.

Any proposal for a target higher than 300ppmv would imply confidence that it is safe to leave the Arctic sea ice melted. If we currently have such confidence, it is misplaced. 300ppmv is below current atmospheric concentrations, but we can achieve it if we act now, because of the delay in how the climate system responds - if we can lower the atmospheric concentrations this century the system may never reach the full level of warming we are due to receive.

This reflects a key point - that the climate is not warmed by our current level of emissions, but rather by the cumulative amount of greenhouse gases in the atmosphere. We may be able to reduce our current emissions relatively quickly, but reducing the atmospheric stock means first bringing our emissions levels below the natural carbon sink capacity of the planet, and then waiting for that capacity to reduce the stock - a process which will take a lot longer. Crucially, this means that cutting emissions 80% will not solve 80% of the problem. The scale of the challenge is daunting. Even under optimistic assumptions, meeting it will require emissions peaking globally by 2015 or sooner, and unprecedented rates of emissions cuts. Whatever our future target for emissions stabilisation - 450, 350, 300 - we ought to be doing much more than we are now. Unless we make emissions cuts in the short term the kinds of stabilisation levels we have been talking about will not be possible. We must race out of carbon - once this process is well under way we can have arguments about what level of atmospheric concentration we want. We must stop pretending that our current course of action will get us what we need. We need a programme of change altogether more ambitious.

Solutions

In the next two years the UK should cut its emissions by 10% - reversing current trends of actual UK emissions growth and peaking our emissions early. Delivering short-term actions provides the essential foundation for mid-term policies and long-term targets.

We should then cut our emissions as close to zero as possible over the next 2-3 decades, delivering a clear message of intent and urgency to the rest of the world. At the same time we should be preserving the UK's carbon sinks and funding adaptation around the world.

Cutting emissions to this degree means decarbonising the UK - a programme of action which combines wide-ranging energy efficiency measures, the rapid deployment of diverse and distributed renewable technologies, and encouraging significant behavioural change. We will have to integrate our transport system with a renewably powered national grid, and make sweeping changes in the way we insulate, heat and build our houses. Agriculture will be faced with the twin challenges of decarbonising and adapting to a warmer world.

Implementing this plan will require that we overcome significant obstacles - such an energy system can compete in terms of cost with our current fossil-fuel powered system, but will require significant investment in the short term. This is a clear opportunity for Government to invest in a sustainable future - raising Government energy bonds against the profits to be made from exporting renewable energy to the rest of Europe. Creating a planning system which can quickly and sensitively increase renewable capacity, building a national grid which can integrate and balance large amounts of renewable power, and investing to overcome skills shortages and supply constraints which are preventing rapid growth in this dynamic sector.

We may also need to explore options beyond decarbonisation. These are poorly understood at present - so-called 'geoengineering' technologies are highly problematic and most can be dismissed out of hand. However, there should be further research into less risky proposals - drawing carbon out of the atmosphere using natural processes, and 'direct air capture', as well as into cloud-seeding ships and certain forms of albedo adjustment.

International action will be required to solve the problem, but it is not a prerequisite for acting. The UK can take unilateral action, and with the currently underdeveloped and valuable asset of our huge renewable potential, is well-placed to do so. In this way, the UK could help unpick the international deadlock which has prevented faster action on climate change.

Action

Current large-scale policy responses to the problem have failed to deliver the change we require, and indeed have failed to deliver emissions reductions at all. The UK Climate Change Bill is a welcome step forward, but the situation we are in will require more ambitious action. To deliver the change we need, we will have to overcome the social and political blockages which have kept us from addressing the problem.

It will be necessary to mobilise public will to break the logjam of political progress. Different groups in government, civil society and the public have important roles to play. Rapid societal shifts are not only possible; they are a regular feature of the way our society works. Although the challenge may seem daunting, we still have the time and agency to respond. By front-loading the action we take to reverse current trends of emissions growth, cutting our emissions in the UK 10% in the next few years, and in seeking to scale up a response that meets the scale of the challenge, we can manage the risks to which we are exposed and act with agency andpurpose.Read the Climate Safety - In Case of Emergency reportClimate Safety, by the Public Interest Research Centre, provides a simple summary of the latest science, delivering a clear message that to have any chance of maintaining a safe climate, we must rapidly decarbonise our society, preserve global carbon sinks, and address the problem with an unprecedented degree of seriousness.Even with a commitment to 80% carbon cuts by 2050, Climate Safety warns that our current policy response does not match up to the scale of the challenge.Visit http://www.climatesafety.org/