Even 2 Degrees of Global Warming Poses Large Climate Risk

Takeaway: the world must treat the 2 degree target as an upper bound in order to minimize climate risk.
  • A 2013 study finds that levels of greenhouse gas emissions previously thought to be consistent with limiting global temperature increase to 2 degrees (regarded by some as a manageable level of warming) risk triggering secondary effects that, in the long term, would result in 3 or 4 degrees of warming.

  • 3 or 4 degrees of warming would have major undesirable consequences such as flooded coastal cities and displaced populations.

  • If no further action is taken, the world is projected to exceed 2 degrees of warming before 2100.