At the beginning of last month, the vlogbrother Hank Green boiled down a new report from the United Nations about global warming, released in October 2013, and tells you five things you really need to know about our warming world.
As such, the report mentioned by Mister Green, Climate Change 2013, literally states the following: “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased”, going on to say that “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” and finally adding that “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 . . . It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century”. In the next instance, the report gives the following bleak yet surprisingly low-key assessment for the future of humanity on earth: “Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions . . . Global surface temperature change for the end of the 21st century is likely to exceed 1.5°C relative to 1850 to 1900 for all Representative Concentration Pathway of RCP scenarios except RCP2.6. It is likely to exceed 2°C for RCP6.0 and RCP8.5, and more likely than not to exceed 2°C for RCP4.5. Warming will continue beyond 2100 under all RCP scenarios except RCP2.6. Warming will continue to exhibit interannual-to-decadal variability and will not be regionally uniform”, and giving the following proviso: “Changes in the global water cycle in response to the warming over the 21st century will not be uniform. The contrast in precipitation between wet and dry regions and between wet and dry seasons will increase, although there may be regional exceptions”. In fact, already two years ago, Dr Curt Stager’s book Deep Future: the next 100,000 years of life on Earth gave us an unsettling view of the future: Most debate over global warming looks only as far ahead as 2100 AD, but what happens after that? As Curt Stager argues, our fossil fuel emissions will interfere with climates for much longer than most of us, scientists included, yet realize. Even in the best-case scenario, the world won’t fully recover for tens of thousands of years, and possibly much longer.
 Climate Change 2013: The Physical Science Basis. Summary for Policy Makers (October 2013). http://www.climatechange2013.org/images/uploads/WGI_AR5_SPM_brochure.pdf.
 Climate Change 2013.
 “Deep Future: Climate Change and the Untimely End of the Coming Ice Age” A Pseudo-Ottoman Blog (27 April 2011). https://sitanbul.wordpress.com/2011/04/27/deep-future-climate-change-and-the-untimely-end-of-the-coming-ice-age/.