United Nation’s Intergovernmental Panel on Climate Change (IPCC) just published their fifth assessment report and the conclusion is that the global warming is caused by human activity and the scientific evidence is overwhelming and incontrovertible.
The Intergovernmental Panel on Climate Change is a scientific body set up in 1988 by the United Nations. It is charged to gather comprehensive scientific assessments of the change in Earth’s climate. Thousands of scientists and other experts contribute in writing this report, which is reviewed by peer representatives from more than 120 countries. The IPCC produces reports which have the agreement of leading climate scientists and the consensus of participating governments.
The report concludes that the human influence on the climatic changes since the mid 20th century is indisputable. The scientific data collected by IPCC shows an unprecdented increase in greenhouse gases in the atmosphere. Human activity has been the main cause of rising land and ocean temperatures, shrinking of snow and ice caps, and in the rise of sea levels.
The findings of the IPCC Report are:
Atmosphere: Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years.
Oceans: Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010. It is certain that the upper ocean warmed from 1971 to 2010, and it is likely that this change occurred between the 1870s and 1971.
Cryosphere: Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent.
Sea Level: The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia. Over the period 1901–2010, global mean sea level rose by 0.19 m.
Carbon and Other Biogeochemical Cycles: The atmospheric concentrations of carbon dioxide (CO2), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. CO2 concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification.
Drivers of Climate Change: Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750.
The import of these numbers should be frightening for us. The resulting changes in our weather patterns would jeopardize human life, would cause massive social displacement and economic losses. When will we heed the clarion call of the scintific community warning us of a series of impending weather related calamities Which would place extra ordinary burden on our food production abilities and fresh water resources.