14 Nov 2007
Follow-up to ‘The Big Melt’ Challenges Assumptions on Co2 Targets.
Not content with having written The Single Scariest Thing I Have Ever Read, the recent **Big Melt** report, David Spratt at Carbon Equity has just produced the second in what will be a series of three reports. The new one, Target Practice; where should we aim to prevent dangerous climate change builds on the insights from the first report, namely that the thawing of the Arctic ice is happening so much faster than anyone had ever thought, nearly 100 years ahead of the IPCC projections and before we have even reached a 1 degree rise in global temperature, that we need to reassess our concept of where a ‘safe’ limit might lie. In the new report, Pratt, now joined by Philip Sutton, asks the question, given that 2 degree is no longer a ‘safe’ limit, where might that limit be?
The key findings of the report are as follows;
• Policies have not been constructed within a framework of fully solving the problem.
• Actions proposed should be doubly-practical: they should deliver tangible results in the real world and crucially they must also fully solve the problem
• We suggest the goal is a climate safe for all people and all species over ‘all’ generations
* The loss of the Arctic sea ice, in all likelihood at an increase of less than 1ºC in global average temperature unambiguously represents dangerous human interference with the climate and therefore global temperatures should not have exceeded the levels three decades ago in order to avoid dangerous climate change.
• The widely-promoted 2ºC is not credible, initiating climate feedbacks on earth and in the oceans, on ice-sheets and on the tundra, taking the earth past significant tipping points.
• Proposals for a 60% cut on 1990 levels by 2050 implies a 3ºC target. The last time temperatures were 3°C higher than our pre-industrial levels, the northern hemisphere was free of glaciers and ice sheets, beech trees grew in the Transantarctic mountains, sea levels were 25 metres higher.
• In order to avoid the loss of the Arctic icesheet, a safe target would be 0.5ºC. We therefore propose that a safe-climate temperature increase cap be 0.5ºC and greenhouse gas level of 320 ppm CO2e, a level to which we should aim to return the planet if we value biodiversity and human life. There is no ideal achievement timetable other than as fast as possible.
• To return to the safe zone we need to bring the global temperature and the atmospheric greenhouse gases down from their present levels; and
• This means that no further greenhouse gases should be added to the air and there needs to be a very significant decay in the level of the short-residence-period greenhouse gases and other positive forcing (warming) agents in the atmosphere (e.g. soot) and a major draw down of CO2 using natural carbon sinks and deliberate human capture and sequestration.
The challenge the report sets is summed up in the graph below. It is worth looking at closely.
A third report, **Rising to the Challenge** (currently in preparation), will look at how to achieve the goals set out in this report. Next time you hear a Minister say that 60% cuts in CO2 by 2050 is ‘ambitious’, send them a copy of the two reports so far and suggest that still holding to 2 degrees as a target is, in effect, condemning humanity to runaway climate change. **Target Practice** spells the end of economic growth, but also offers an unleashing of human creativity unparalleled in history.