The Big Melt is a new report from Australian climate campaigner David Spratt of Carbon Equity. It warns that the latest data shows the effects of climate change are speeding up, with real dangers of the setting in of self-perpetuating, deepening "runaway" global warming.
The Arctic's floating sea ice is headed towards rapid summer disintegration and open blue seas as early as 2013, a century ahead of the International Panel on Climate Change (IPCC) projections, according to dramatic forecasts this year. The Arctic ice cap shrank so much in the (northern hemisphere) summer of 2007 "that waves briefly lapped along two previously fabled Arctic shipping routes, the Northwest Passage over Canada and the Northern Sea Route over Russia", the October 7 New York Times reported.
Even climate sceptics are being convinced by the new data. "We used to argue that a lot of the variability up to the late 1990s was induced by changes in the winds, natural changes not obviously related to global warming", said John Michael Wallace, a scientist at the University of Washington who was quoted by the NYT. "But changes in the last few years make you have to question that. I'm much more open to the idea that we might have passed a point where it's becoming essentially irreversible."
The Big Melt explains that large areas of the Arctic sea ice are now only one metre thick. This is down from a thickness of 3.5 metres in the early 1960s, and around 2.5 metres in the late 1980s and early 1990s. The report continues: "The decrease in both extent and thickness suggests that the summer sea ice has lost more than 80 per cent of its volume in 40 years. When the sea ice thins to around half a metre in thickness, it will be subject to even more rapid disintegration by wave and wind action."
"The reason so much [of the Arctic ice] went suddenly is that it is hitting a tipping point that we have been warning about for the past few years", says James Hansen, director of NASA's Goddard Institute for Space Science and one of the world's top climate scientists.
Furthermore, global greenhouse gas pollution not only continues but, as The Big Melt states, "emissions are rising at an increasing rate. A May 2007 study found the annual growth in global CO2 emissions caused by human activity jumping from an average 1.1 per cent for 1990–1999 to more than 3 per cent for 2000–2004."
Hansen estimated that at the current growth rate of CO2 emissions — about 2% per year — by 2015 emissions will be 35% greater than they were in 2000. This would make it difficult, if not impossible, to avoid dangerous climate change.
The Big Melt argues that the IPCC is no longer reliable due to "scientific reticence" and deficient process. It cites Hansen explaining that scientific reticence, in at least some cases, "hinders communication with the public about dangers of global warming".
It continues: "Scientific reticence may be a consequence of the scientific method. Success in science depends on objective skepticism. Caution, if not reticence, has its merits. However, in a case such as ice sheet instability and sea level rise, there is a danger in excessive caution. We may rue reticence if it serves to lock in future disasters."
The Big Melt concludes with a message for climate campaigners. "The primary assumptions on which climate policy is based need to be re-interrogated", it argues. "Take just one example: the most fundamental and widely supported tenet — that 2°C represents a reasonable maximum target if we are to avoid dangerous climate change — can no longer be defended.
"Today at less than a 1°C rise, the Arctic sea ice is headed for very rapid disintegration, in all likelihood triggering the irreversible loss of the Greenland ice sheet and catastrophic sea level increases.
"The 2°C warming cap was always a political compromise, but with the speed of change now in the climate system and the positive feedbacks that 2°C will trigger, it looms for perhaps billions of people and millions of species as a death sentence.
"The simple imperative is for us to very rapidly decarbonise the world economy and to put in place the means to draw down the existing excess CO2 levels. We must choose targets and take actions that can actually solve the problem in a timely way. It is too late not to be honest with ourselves and our fellow citizens."
[The Big Melt: Lessons from the Arctic Summer of 2007 is available for free on the web at