The Summary for Policy Makers (SPM) from the Intergovernmental Panel on Climate Change (IPCC) was released overnight in Valencia, Spain. If there is one thing that you are going to read from the IPCC, then it should be this document.

This is the final phase of the 4th Assessment report. The SPM draws together the evidence, discussion and conclusions of the 3 IPCC working groups from the fourth assessment report and provide it as a no-nonsense, on-partisan digest for policy makers.

Summarizing most the conclusions that fall into the IPCC’s ‘likely’ to ‘almost certain’ categories, the following seems to true for climate change. We are now in a rapidly warming climate that is changing natural and human systems. The burning of fossil fuels and land-use change by humans is driving these changes. Ice is disappearing from our glaciers and snow fields, water supplies are drying up and food production is being threatened. Natural ecosystems from rainforest to the southern ocean are changing rapidly. Millions of lives are threatened by the combination of a hot house future, with rising sea levels and intensifying natural disasters.

The synthesis highlights several growing certainties. These are that our current trajectory will put us into a world which is described at the upper end of the IPCC trajectories. “There is high agreement and much evidence that with current climate change mitigation policies and related sustainable development practices, global GHG (Green House Gas) emissions will continue to grow over the next few decades.“

Specifically, this will involve the loss of water supplies to hundreds of millions, the loss of coral reefs, rainforests and other significant global assets, the loss of 50% or more of species, increasing crop failures at low latitudes, inundation of coastal areas, and a rapidly rising death toll from disease, flooding and heat waves. The kicker is that many of these impacts, while serious at high latitudes will be greatest for developing nations which are mostly clustered at low latitudes.

The worst impacts will be on those people who least can afford to respond. Hence, in the words of Yvo de Boer, executive secretary of the UN Framework Convention on Climate Change (UNFCCC), “Failing to recognize the urgency of this message and acting on it would be nothing less than criminally irresponsible.”

There are many messages within the SPM form the 4th assessment report. Some of these are ominous. For example, the prospect of the breakup of the ice sheets sitting above sea level in Greenland and Antarctica is mentioned in various places. This and ocean acidification have entered the report with growing significance.

“The eventual contributions from Greenland ice sheet loss could be several meters, and larger than from thermal expansion, should warming in excess of 1.9-4.6°C above pre-industrial be sustained over many centuries.”

Several of the leading research groups focused on sea level feel that sea level will be much higher this century. If it is, then the chance of severely crippling human society across the board goes up dramatically. Just think of the position that Australia, USA or Europe would be in with 2 m of sea level covering our port facilities?

It is important to remember that this is a conservative statement, given the nature of consensus and the IPCC process. The process of winning consensus on scientific ideas (no doubt frustrated by political interference all the way) takes time and the reading of the past 3 assessment reports since 1990 suggests that the best way to read this report is to take anything from the ‘likely’ and above in this report and read it as gospel as to what is going to happen in the coming decades and century.

Lastly, one of the most important tables appears at the back with the SPM:

“In 2050, global average macro-economic costs for mitigation towards stabilization between 710 and 445ppm CO2-eq are between a 1% gain and 5.5% decrease of global GDP (Table SPM.7). This corresponds to slowing average annual global GDP growth by less than 0.12 percentage points.”

This table outlines the costs that we would occur if we were to choose to pursue the stabilization of greenhouse gas levels at various level. The most interesting case in this table is that of stabilizing atmospheric carbon dioxide at 445 ppm.

Remember, this is the concentration of carbon dioxide in the atmosphere at which we would not completely lose coral reefs and other critical natural ecosystems. Any higher, and you get into the realm of losing these natural ecosystems as well as throwing much of the world into chaos over water and food security.

The information on the table is quite stunning in its implications (and difference from the opinions of some politicians who say we can’t afford to do much about climate change). According to IPCC expertise, putting in place the measures to ensure that we stabilise atmospheric carbon dioxide levels at 445 ppm would shave less than 0.12% off average annual GDP growth rate for the global economy. This is a tiny figure which becomes more significant when one considers the potential costs outlined of not acting.

It seems to be a tiny amount of insurance to pay relative to the potentially costly and catastrophic future that lies ahead if we don’t act.

Given that the cost of acting per year is less than 0.12% of average annual GDP – yet the costs of not acting are enormous and potentially catastrophic, one wonders why the USA and Australia’s leadership have not ratified Kyoto and got on with the job of dealing with this crisis. Seems logical. On the face of it, however, and after reading liberal party member Guy Pearse’s book “High and Dry” this appears to be more about an out-of-touch government being captured by special interests.