Assignment is to read the 22 page IPCC AR4 summary for policymakers Essay

Assignment is to read the 22 page IPCC AR4 summary for policymakers (SPM) (Introduction plus 5 sections) and write a concise summary of it - Essay Example shift in animal and plant ranges together with the earlier timing of various spring events has been linked to warming in the terrestrial ecosystems while changes in ice, frozen ground and snow have resulted in a general increase in both the total number and size of glacial lakes (Ipcc, 2007). It has been shown that the energy balance of the world’s climate system has been altered by changes in the atmospheric concentration of aerosols and various green house gases, solar radiation and total land cover. During the period ranging between 1970 and 2004, Carbon dioxide emissions have been shown to have grown by about 80%. The atmospheric concentration methane and carbon dioxide have exceeded the pre industrial levels recorded from ice cores over the last 650,000 years. This has mainly been attributed to the use of various agricultural products and fossil fuels (Ipcc, 2007). If the Emission of GHG continues at the current rate, this will potentially cause changes in the planet’s global climate system to be larger in the 21st century than those previously observed in the 20th century. Warming is expected to reduce the ocean and terrestrial uptake of CO2 resulting in an increase in the ocean’s acidity with an expected average decrease of its PH by about 0.1 units (Ipcc, 2007). The Greenland ice sheet is expected to continue contracting, a factor that is expected to continue playing a vital contribution to the increasing rise in sea levels after 2100, with various models suggesting the eventual virtual complete elimination of the ice sheet after a millennia. There are several adaptation and mitigation options available touching on various aspects. These include expanding water storage, harvesting and conservation techniques, the adjustment of agricultural product varieties and planting dates, reduction of the world’s dependency on a mostly single source of energy and opting for green energy, creation of storm surge barriers and sea walls to help create a