The safe level of atmospheric carbon dioxide is no more than 350 parts per million (ppm), if we wish the diversity of other species on the planet to survive – as well as "amenities" that humans require, such as fresh water supplies, stable coastlines and a normal degree of extreme weather events.
That is the safe level of atmospheric concentration of CO2 as expressed in parts per million.
The UNFCCC does not, however, identify the safe levels of atmospheric GHG concentrations.
Best to be safe and boil at atmospheric pressure (if you have ever boiled milk you have seen foaming over, no doubt; cooked milk makes a glue called casein and can even make milk into stone, when cooked with vinegar).
The IEA's "450 scenario", in which the levels of atmospheric carbon stay within safe limits, China's non-fossil energy would triple between today and 2030.
The clinically safe, maximum rate of return to atmospheric pressure depends on both the amplitude of the hyperbaric exposure (for example, water depth) and its duration.
After reviewing citations that referred to safe or "naturally occurring" levels of atmospheric lead, summit organizer and historian Alexander More, M.A. '07, Ph.D. '14, said that much of that research is funded by lead and other chemical lobbies.
"That will be the challenge at Lake Oroville in the coming months — keeping people downstream safe while managing the dam itself," atmospheric scientist and Washington Post weather editor Angela Fritz wrote Tuesday.
Less atmospheric but self-consciously safer is the YWCA Hotel (733 Beatty Street; 604-895-5830; www.ywcahothe.com), acrostreet street from BC Place, where the opening and closing ceremonies of the 2010 Games are scheduled to take place.
Rademakers and others believe that if sufficient amounts of biochar were produced – both on the micro and small industrial scale – the world could reduce atmospheric CO2 concentration to a safe level at the same time as increasing food production.
