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."
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.
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.
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.
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."