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Summary of the Summary: A Breakdown of the IPCC Fourth Assessment Report

Posted Nov 19 2007 4:15pm
If there's one thing our current climate needs, it's the unbiased information we can depend on from the 2007 Nobel Peace Prize-winning Intergovernmental Panel On Climate Change (IPCC), founded in 1990 to gather and analyze all available scientific research on climate change.

In 2007, the IPCC released its fourth assessment report in three separate installments. Now they've condensed these findings into one "Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessement Report."

Though a summary, it's still an intimidating 25 pages. Yet, everyone on the planet needs to know what's in this report, which inspired this "Summary of the Summary."

1. Observed changes in climate and their effects

Scientists know global warming is happening because of the following observational evidence:
- Increases in global average air and ocean temperatures
- Widespread melting of snow and ice
- Rising global average sea level

Other observations likely linked to global warming are:
- Increased precipitation in some areas, increased drought in others
- More hot days and nights that cold ones
- Increased frequency of heat waves
- Increased intensity of tropical cyclone activity

We've already seen the effects on natural systems, such as the warming of lakes and rivers, ground instability in permafrost regions and shifts in plant and animal ranges. We've also seen life-altering effects, such as the dying of coral reefs, heat-related human deaths and changes in infectious diseases.

2. Causes of change

The report cites four "changes in atmospheric concentrations" that "alter the energy balance of the climate system." They are 1) land-cover, 2) solar radiation, and increases in 3) aerosols and, yes, 4) greenhouse gases.

Anyone who doubts that industrialized human activities are causing global warming need only consider this:

Between 1970 and 2004, human-produced greenhouse gas emissions rose by 70%! The biggest climate change offender -- carbon dioxide (CO2) -- went up 80% during that same time period.

Now let's put that into perspective.

"Atmospheric concentrations of CO2 ... in 2005 exceed by far the natural range over the last 650,000 years."

3. Projected climate change and its impacts

If we do not take immediate, dramatic action to find more sustainable ways of creating energy, then greenhouse gas emissions are only going to grow. At this rate -- continuing to use fossil fuels as our main energy source -- greenhouse gases in our environment are estimated to increase by 25-90% between now and 2030!

By region, here's some of what we can expect in:

Africa -- Increased water stress; 50% reduction in yield from rain-fed agriculture; sea-level rise in highly populated coastal areas.

Asia -- Decrease in fresh water availability; increased flooding from the sea; disease associated with floods and drought.

Australia and New Zealand -- Loss of biodiversity, such as in the Great Barrier Reef; water insecurity; decrease in crop and forest production; and coastal flooding.

Europe -- Increased risk of inland flash floods; more frequent coasting flooding; increased health risks from heat waves and wildfires. In mountainous areas, glacier retreat; reduced snow cover and winter tourism; and extensive species loss. In southern Europe, reduction in water availability and crop productivity.

Latin America -- Signficant species extinction; decrease in crop productivity and food security; decrease in availability of drinking water.

North America -- Decreased snow packs and more winter flooding in western mountains; increased intensity of heat waves and stress on coastal communities.

Polar Regions -- Detrimental impact on animals due to thinning glaciers and ice sheets; detrimental impact on human ability to continue their indigenous ways of life.

Small Islands -- Storm surge and erosion from sea-level rise; deterioriation of coastal conditions; erosion of beaches and coral bleaching; reduction in fresh water availability; increased invasion of non-native species.

Affecting every region, though, is the melting of Greenland's ice sheet. The predictions for it are "virtually complete elimination," which will result in a sea-level rise of 7 meters.

Also affecting many regions is the increased threat of extinction to an additional 20 to 30% of species.

4. Adaptation and mitigation options

To adapt to, and mitigate, climate change, we must incorporate sustainable practices into every sector of our lives, most of which will benefit from international cooperation.

Energy Supply Sector -- Supply and distribution efficiency; hydropower, solar, wind, geothermal and bioenergy sources; Carbon Dioxide Capture and Storage; reduction of fossil fuel subsidies, taxes or carbon charges on fossil fuels.

Transport Sector -- More fuel-efficient vehicles and hybrids; biofuels; public transportation; mandatory fuel economy, biofuel blending and CO2 standards.

Buildings Sector -- Efficient lighting and daylighting; appliance standards and labels; improved cook stoves; solar heating and cooling; building codes and certification; incentives for energy service companies.

Industry Sector -- More efficient end-use electrical equipment; material recycling and substitution; performance standards, subsidies and tax credits.

Agriculture Sector -- Improved crop and grazing land management to increase soil carbon storage; improved rice cultivation techniques and livestock and manure management; financial incentives and regulations; efficient use of fertilizers and irrigation.

Forestry Sector -- Reduced deforestation; reforestation; harvested wood produce management; financial incentives.

Waste Sector -- Landfill CH4 recovery; waste incineration with energy recovery; composting of organic waste; controlled waste water treatment; financial incentives; waste management regulations.

5. The long-term perspective

Most of the information in this section touches on the points already made in the sections above. Worth nothing, though, is the monetary cost of climate change.

The cost in 2005, for example, was an average of US$12 per ton of carbon dioxide.

"Choices about the scale and timing of greenhouse gas mitigation involve balancing the economic costs of more rapid emission reductions now against the corresponding medium-term and long-term climate risks of delay."

To read the full report, which includes many graphs and tables, click this link to the PDF document of "Summary for Policymakers of the Synthesis Report of the IPCC Fourth Assessment Report." For more information about the IPCC, click this link to the IPCC website.
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