A scientifically based report released in Stockholm, Sweden on Friday by the Intergovernmental Panel on Climate Change (IPCC) stated that not only does human activity influence global climate change but human activity is also the main cause of this change.
This report is the fifth assessment report (AR5) from the IPCC; an assessment report is released every six years. It is based upon numerous sets data across various systems and strengthens the scientific consensus from previous reports and vast multitudes of scientific studies over past decades that climate change is set to continue throughout the century and that human activity is the key driver of global warming over the past 60 years.
“Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system,” the report emphasized.
In determining its conclusions the report detailed changes in various global systems including increases in land and ocean surface temperatures, increases in sub-surface ocean temperatures, increases in ocean thermal expansion, drastic reductions in arctic sea ice extent, increases in glacier melt around the world, increases in atmospheric temperatures at varying levels, changes in “natural variability” trends such as El Nino, changes in precipitation, decreases in the number of cold days and nights, increases in warm days and nights, increases in ocean evaporation rates based upon salinity, decreases in snow cover, increases in permafrost temperatures and increases in sea levels.
Scientific data show that the primary cause of increases in global temperatures is from greenhouse gases in the atmosphere and the report noted that it is ‘extremely likely’ that over 50% of greenhouse gases over a sixty-year period from 1951 until 2010 came from sources directly related to human activity.
“Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes,” the IPCC reported. “This evidence for human influence has grown since AR4. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.”
AR4 is the notation for the 4th assessment report on climate change released by the IPCC in 2007.
According to findings, human influence on climate change has been observed in six of the seven continents: Africa, Asia, Australia, Europe, North America and South America. In addition, the large amount of Arctic warming and sea ice melt has “likely” been affected by human activity. The report noted that there was “low confidence” on data pointing to human influence in Antarctica due to “large observational uncertainties.”
The report uses a rating system of confidence levels from “very low” to “very high” to rate each set of data and likelihood probabilities ranging from “exceptionally unlikely” to “virtually certain.” If there is a lower confidence level in a specific set of data, it may mean that the data is somewhat inconclusive or it may mean that there is not yet enough data to warrant a higher confidence level in the conclusion. Such a rating system follows standard scientific method for reaching conclusions.
In a press statement on Friday U.S. Secretary of State John Kerry called the report’s findings “a wake-up call,” adding, “If this isn’t an alarm bell, then I don’t know what one is. If ever there were an issue that demanded greater cooperation, partnership, and committed diplomacy, this is it.
“Once again, the science grows clearer, the case grows more compelling, and the costs of inaction grow beyond anything that anyone with conscience or common sense should be willing to even contemplate,” Kerry stated.
“This isn’t a political document produced by politicians,” he added, “it’s science. It builds on the most authoritative assessments of knowledge on climate change produced by scientists, who by profession are conservative because they must deal in what is observable, provable and reviewable by their peers.”
In late June of this year U.S. President Barack Obama announced a sweeping multi-step plan to combat and prepare for the effects of climate change.