As the founder of the Worldwatch Institute and the founder and president of the Earth Policy Institute, author or co-author of over 50 books on global environmental issues and recipient of 26 honorary degrees, described by the Washington Post as "one of the world's most influential thinkers", Lester Brown can be relied on for a good-enough initial summary of the condition of our planet. 

In his talk  at the 40th anniversary of the publication of The Limits to Growth hosted by The Club of Rome and the Smithsonian Institution, Lester Brown explains how the buffers that could allow our global system to come back to equilibrium in the case of a disruption (his example is a substantial loss of crops due to a drought) have been depleted.