IPCC report: Humans are “dominant cause” of global warming since 1950s

BBC : The UN’s Intergovernmental Panel on Climate Change (IPCC) has released the first of its three-part report on climate change, the sixth assessment since 1995. The most significant finding in the 36-page summary is the consensus among climatologists that humans have been the primary driving force behind the global warming trend since the 1950s. The report downplays the apparent slowdown in warming since 1998: That year was exceptionally warm because of El Niño , and short time periods do not necessarily reflect long-term trends. In the 2007 report, the temperature range that corresponds to a doubling of atmospheric carbon dioxide levels was 2.0–4.5 °C; the new report revises that to 1.5–4.5 °C. Among the other findings are that ocean levels will rise between 26 cm and 82 cm by 2100, depending on greenhouse gas emissions; ocean temperature increases account for 90% of the energy added to the climate system over the past 40 years; and by the end of this century, the average global surface temperatures will reach 1.5 °C over their average in 1850.