SUMMARY of the Summary of the 2007 IPCC AR4 Synthesis Report

The Inter-Governmental Panel on Climate Change has finally released the last of its 2007 Fourth Assessment Reports together with a “Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report (AR4) †(see:

You will no doubt have heard, read or viewed media reports about the latest shocking IPCC report e.g. see the Science news summary of the summary of the Synthesis report.

What follows below is a convenient and succinct SUMMARY of this Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report.

People from over 130 countries contributed to the IPCC Fourth Assessment Report over the last 6 years. These people included more than 2500 scientific expert reviewers, more than 850 contributing authors, and more than 450 lead authors.

The research basis of their findings is on an edifice of thousands of scientific papers in peer-reviewed scientific journals going right back to John Tyndall’s pioneering work in the 19th century on the light absorption and thermodynamic properties of water vapour and other gases. (Indeed a valued book in my personal library is John Tyndall’s “Fragments of Science†(Appleton, New York and London, 1886) that deals with this very problem).

The various Working groups have produced a succession of reports: the Working Group I Report “The Physical Basisâ€; the Working Group II report “Impacts, Adaptation and Vulnerabilityâ€; the Working Group III Report “Mitigation of Climate Changeâ€; with all of these accompanied by detailed Summaries for Policymakers.

“Climate Change 2007â€, the IPCC Fourth Assessment Report (AR4) has finally been completed with the recent release of the final “Synthesis Report†and its accompanying Summary for Policymakers.

Before providing a detailed SUMMARY of the “Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report†some general points should be made about Scientific methodology and the Scientific culture.

Science is about the critical experimental testing of potentially falsifiable hypotheses – it is the precise opposite of the unfortunately all too prevalent “spin†(beloved by Bush-ites) that involves the selective use of asserted facts to support a partisan, political position.

Scientific experimentation typically involves measurements that are expressed as numbers with “units†(e.g. feet for length, feet per second for velocity etc). Experimental variability can be assessed statistically by parameters such as “means†and “standard deviations†from the mean value. Statistical tests can be applied to such “noisy†data to give an idea of the probability that the observed departure from a hypothetical expected result is due to chance variability i.e. in order to give a quantitative assessment of the likelihood of the proposed model.

Scientists write up their results as scientific papers which are then subject to expert scientific “peer review†before the final, edited paper is published. Intrinsic scientific scepticism means continual critical assessment of the scientific literature so that hypotheses (or “modelsâ€) about reality are continually improved.

The IPCC AR4 report ultimately involved thousands of scientists in various capacities and may have been based upon tens of thousands of such recently and expertly produced and reviewed scientific papers. A personal example involving ONE such scientific paper may assist here – last year I was a co-author on a scientific paper defining the complex molecular structure of a toxin, the work took 5 years, co-author researchers included a professor and an associate professor (each with 40 years of 6 days a week professional scientific experience), a senior lecturer (20 years’ experience) and 2 PhD students (each with 4 years undergraduate work and 4 years post-graduate research experience).

Yet all of this expertise of dedicated scientists could be significantly neutralized publicly by the “spin†of a notorious “climate sceptic†Australian leader who commented on the IPCC Report by simply saying of the climate change warnings that “it’s not going to happen tomorrow†(incorrectly, as it happens, because it already HAS happened in many ways specified in the Report).

The final “Synthesis Report†and its Summary for Policymakers was subject to a detailed process of consensus – the scientific data (vetted through the processes outlined above) was not deleted but intense negotiation occurred about the WORDS used. Hence the Summary is continually qualified by words such as “likelyâ€, “very likelyâ€, “medium confidenceâ€, “high confidenceâ€, “very high confidenceâ€, “high agreement†etc.

As my Summary of the Summary will hopefully make clear (and following the numbered headings used in the IPCC Summary), the Synthesis report documents that anthropogenic climate change is occurring; damage to the planetary environment and sustainability has ALREADY occurred; “adaptation†is needed in relation to current and expected further damage; and that “mitigation†of greenhouse gas (GHG) production should be urgently instituted.

1. Observed changes in climate and their effects

Warming of the planet is unequivocal, with 11 of the last 12 years being the hottest since 1850. Northern latitudes have differentially warmed and land has warmed faster than oceans. Sea levels are rising and at an increasing rate, snow and ice extent have decreased, Arctic ice extent had decreased and glaciers and snow cover have declined. While precipitation in 1900-2005 has increased in Eastern North and South America, Northern Europe and Northern and Central Asia, it has declined in the Sahel, the Mediterranean, Southern Africa and parts of Southern Asia (Australia is still in the grip of its worst ever recorded drought). Over the last 50 years, cold days, cold nights and frost have become less frequent and hot days, hot nights and heat waves more frequent. Tropical cyclone activity in the North Atlantic has increased. Average Northern Hemisphere temperatures in the latter half of the 20th century are the highest in the last 1300 years.

Temperature increase is impacting many natural systems, especially in relation to snow, ice, frozen ground, glacial lakes and ground instability in mountain and other permafrost regions with changes in these and Arctic and Antarctic ecosystems (Northern Hemisphere ice and snow cover is declining) . Hydrological systems have been affected by increased runoff, there are earlier spring events and poleward shifts in plant and animal terrestrial ranges. Range changes are also occurring in marine and freshwater systems in relation to algal, zooplankton and fish abundance and associated with temperature, ice cover and salinity changes.

Some significant changes are emerging in relation to agriculture and forestry (earlier spring planting, forest fires and pests), human health (heat wave mortality, changes in disease vectors and allergenic pollen shifts) and human recreation (e.g. skiing and hunting).

2. Causes of change

Global Greenhouse Gas (GHG) emissions (principally carbon dioxide, CO2, methane, CH4, and nitrous oxide, N2O) due to human activity have increased markedly since 1750 and far exceed pre-industrial values. CO2 (379 ppm) and CH4 (1774 ppb) exceed the natural range for 650,000 years. CO2 comes from fossil fuel burning and land-use; CH4 comes from animal husbandry, agriculture and rotting vegetation. N2O comes from agriculture. While CH4 production has slowed, annual CO2 pollution is steadily growing.

Detailed graphs of temperature increase in the period 1906-2005 for various regions, the world, global land and global oceans show that the observed changes upwards since about 1950 are consistent with modelled outcomes involving both man-made (GHGs) plus natural (solar activity, volcano) “climate forcings†– whereas modelled changes due to natural forcings (changes in solar activity, volcanic eruptions) are roughly constant.

Accordingly it is very likely that the observed changes in temperature since the mid-20th century are due to increased GHG concentration and that man-made GHG changes are with various degrees of certainty responsible for the observed sea level rises and increased heat waves, droughts, ice-melting, de-glaciation, and ecosystem changes observed since 1950.

3. Projected climate change and its impacts

This is the most alarming part of the Report. GHG emissions will continue to grow over the coming decades with current practices. The current CO2 concentration is about 380 ppm but current GHG emission rates (from the very latest literature not considered by the IPCC) place us in the worst scenario envisaged by the previous Third Assessment Report (TAR). This scenario leads to temperature increases of 2.4-6.4 degrees centigrade and sea level changes of about 0.3 -0.6 metres (2090-2099 relative to 1980-1999) 9and in section #5 we are told that it will yield CO2 levels of 660-790 ppm).

The IPCC Special Report on Emissions and Scenarios (2000) (SRES) projects increase in global GHGs by 25-90% over the period 2000-2030 with fossil fuels dominant to 2030 and beyond. Continued GHG emission at or above current rates would induce 21st century climate changes greater than those observed in the 20th century. Even if GHG pollution is severely constrained, long half-lives for GHGs means that the temperature will still increase for several decades. For the next 20 years a warming of 0.2 degrees per decade is projected for a variety of SRES scenarios.

Some of the global projections are for INCREASES in heat waves, sea level, forest fires, deforestation, ocean acidity, pole-ward shift of extra-tropical storm tracks, high latitude precipitation, tropical cyclone intensity, regional drought, ice melting, deglaciation, and permafrost thaw depth, and DECREASES in forests, glaciers, snow cover, subtropical precipitation, sea ice extent (Arctic ice will disappear completely in summer), water resources, ocean pH, ocean phytoplankton and fishery reserves.

The very detailed and lengthy region by region projections are alarming. Thus in Africa by 2020 (only a dozen years away) 75-100 million people will have increased water stress and regional agriculture could decrease by 50% with massive increases in malnutrition. In contrast, in prosperous Australia, by 2020 there will be major damage to the Great Barrier Reef and other ecologically rich sites that is already evident and further decades will see further intensification of current drought and huge bush-fires.

Even more worrisome is the prediction that anthropogenic warming could lead to abrupt and irreversible impacts such as polar ice loss, huge sea level changes, mass extinctions of as many as 40-70% of species assessed, and major damaging changes to marine animal and plant ecosystems.

Perhaps the most chilling sentence in this large section of the Summary is the last sentence: “Changes in terrestrial and ocean CO2 uptake may feed back on the climate systemâ€. This indeed is the thesis of Professor James Lovelock FRS in his recent book “The Revenge of Gaiaâ€. Lovelock says that at 500 ppm CO2 (perhaps the best many say we can hope to stabilize at) there is a crash in the ocean phytoplankton system (that crucially sequesters CO2 and promotes cloud formation through dimethyl sulphide production), Greenland ice melts and there is a positive feedback to exacerbate global warming through the “albedo flip†– decreased light-reflecting clouds and ice and increased light-absorbing “black†water.

I looked in vain in the Summary for a “consensus statement†about what atmospheric CO2 concentration is catastrophic for global temperature in this irreversible impact, positive feedback and “loss of control†sense (for discussion see “Climate Criminals and Climate genocideâ€).

4. Adaptation and mitigation options

The Summary describes all kinds of obvious ways in which we can ADAPT to global warming, listing all kinds of adaptations, strategies, options, policy frameworks, constraints and opportunities in areas such as water, agriculture, infrastructure, towns and cities (especially those in coastal locations), human health, tourism, transport and energy. The Summary then goes on to summarize all kinds of technologies, policies, measures and constraints relating to obvious ways in which we can MITIGATE GHG pollution in the areas of energy supply, transport, buildings, industry, agriculture, forestry, forests, and waste. A distinction is made between “bottom up†studies emphasizing specific technologies and regulations and “Top-down†studies relating to global, macro-economic, economy-wide aspects.

This is a valuable section for Green activists in particular in relation to what we can do.

In particular the Summary says that “ an effective carbon-price signal could realize significant mitigation potential in all sectorsâ€, quoting modelling studies indicating that “global carbon prices rising to 20-80 US$/tCO2-eq by 2030 are consitent with stabilization at around 550 ppm CO2â€.

However what is apparently NOT mentioned is the “true cost†of fossil fuels (as opposed to the politically- and market-determined “workable†“carbon price signalâ€. Thus a Canadian Ontario Ministry of Energy study has estimated that the “true cost†of coal-based electricity (taking into account conservatively-estimated environmental costs and human morbidity and mortality costs from coal burning pollutants) is 18cents/kWh as compared to the market cost of 4 cents/kWh – and at that level all major existing renewable technologies (except for silicon-based photovoltaics) become CHEAPER than coal). (see “Renewables – how the numbers stack upâ€).

5. The long-term perspective

The climate criminal Bush Administration’s “softening†influence on this consensus document is “very likely†seen in the first and last sentences of this part of the Summary: “Determining what constitutes “dangerous anthropogenic interference with the climate system,†in relation to Article 2 of the UNFCCC (UN Framework Convention on Climate Change) involves value judgements. Science can support informed decision on this issue, including by providing criteria for judging which vulnerabilities might be labelled “key†…Choices about the scale and timing of GHG mitigation involve balancing the economic costs of more rapid emission reductions now against the corresponding medium-term and long-term climate risks of delayâ€.

The major RISKS identified include risks to unique and threatened systems (islands, coral reefs, 20-30% of plant and animal species risk extinction if temperatures rise a further 1.5-2.5 degrees centigrade); risks of extreme weather events (droughts, heat waves, flood, cyclones); risks in distribution of impacts and vulnerabilities (people in low latitudes and less developed areas, especially in drier and mega-delta regions); aggregate impacts (economic benefits peak at low warming levels, damages are higher at higher warming levels); risks of large-scale singularities (sea level rise; Greenland, Arctic and Antarctic ice sheet melting).

This section tabulates various stabilization scenarios (categories I-VI) that are very alarming.

Of these, category IV seems the most favoured in public discussion (e.g. in report by Sir Nicholas Stern) and involves stabilization at 485-570 ppm CO2 , 3.2-4.0 degrees centigrade temperature rise above pre-industrial temperature (2-3 degrees above today’s) and 0.6-2.4 metres sea level above the pre-industrial sea level or 0.4 – 2.2 metres above today’s). However Professor Lovelock thinks that 500ppm CO2 would cause disastrous phytoplankton and Greenland ice losses with irreversible loss of major global temperature controls.

Category VI (and current global GHG pollution EXCEEDS that specified in this worst-case scenario) involves stabilization at 660-790 ppm CO2 (twice today’s level of 379 ppm) , 4.9-6.1 degrees centigrade temperature rise above the pre-industrial (4-5 degrees above today’s) and 1.0-3.7 metres sea level above pre-industriall sea level or about 0.8-3.5 metres above today’s)..

A key omission from this section (“very likely†due the Bush Administration pressure but also possibly because of limits on considering the most recent scientific literature ) is how we are ACTUALLY doing in relation to mitigation of CO2 pollution.

The IPCC (2000) SRES scenarios are summarised in New Scientist, with the worst case scenario being the fast economic growth and globalization, fossil fuel-intensive A1F1 scenario in which global population peaks in mid-century and declines thereafter, and involving the rapid introduction of new and more efficient technologies.(see:

However recent data from 2 independent sources (see: “Recent CO2 rises exceed worst case scenariosâ€, New Scientist) reveal that ACTUAL rates of CO2 emission are the same or worse than in the worst case scenario A1F1 that, according to the 2007 IPCC Summary, will lead to catastrophic, long-term stabilization at (upper estimates) 790 ppm CO2, and a 6 degree centigrade higher temperature and 3.7 meter sea level rise relative to pre-industrial levels i.e. CO2 catastrophically at twice today’s level of 379 ppm , temperatures 4-5 degree centigrade above today’s and sea level 0.8-3.5 metres above today’s.

Thanks to climate criminal, climate genocidal countries, notably Bush America (the world’s #1 GHG polluter) and Bush-ite Australia (the world’s #1 coal exporter) – noting that neither of these will constrain GHG pollution nor sign Kyoto - the world is on track to deliver this predicted catastrophe or even WORSE to our children and grandchildren.

Dr Gideon Polya published some 130 works in a 4 decade scientific career, most recently a huge pharmacological reference text "Biochemical Targets of Plant Bioactive Compounds" (CRC Press/Taylor & Francis, New York & London, 2003). He has just published “Body Count. Global avoidable mortality since 1950†(G.M. Polya, Melbourne, 2007: and He is very actively involved in a Melbourne, Australia Climate Action Group. For his commentary on global warming as a painter of HUGE polemical paintings, see: “US Nuclear, Greenhouse & Poverty Threats. “Apocalypse Now†Paintingâ€: and “War on Terra, Climate Criminals. “Terra†paintingâ€:

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Dr Gideon Polya
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Guest Eric from GetSolar

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While I share your worries about current climate policy in the United States and Australia, and the imperative for action is upon us for issues of climate change, I do not believe that the activities of one administration will permanently cripple efforts to adjust for the possible catastrophes of global warming. Human ingenuity is a remarkable force. The current generation of young people is firmly behind the idea of curbing carbon emissions and the pace of global warming, and legions of very intelligent people in politics, the arts, economics, philanthrophy, academia, science, and, most importantly, business are preparing ideas for the upcoming green transition. The failure to sign Kyoto is a real one. But it will not cripple the process of change.

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Guest Dr Gideon Polya

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I agree, Eric, that it is not all gloom and doom. Thus if the "true cost" of coal-based electricity is considered (about 18 cents per kiloWatt hour ) then (depending on size, location etc) wind, geothermal, wave, tide and concentrated solar power are CHEAPER - and accordingly economics and the market place should EVENTUALLY stop GHG pollution. In the end I agree with Professor Mark Diesendorf (a top Australian renewables and energy policy academic) that the science, technology and economics are clear - what is lacking is the political will to stop the climate criminal, terracidal fossil fuel burners. However the current reality is that that while America has only 4.7% of the World's population it consumes about 25% of the world's resources and together with climate criminal Australia (the world's #1 coal exporter) refuses to sign Kyoto, or seriously slash GHG pollution. As the article makes clear world GHG pollution rate STILL equals or exceeds that for the worst of the IPCC scenarios. For a comparative quantitation of "annual per capita fossil-fuel derived CO2 pollution" see: "War on Terra, Climate Criminals. "Terra" painting" at the link below or at .

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