joining us to discuss what this means is crisfield, the director of the was institute for the environmentnk you so much for your time. >> thank you for having me. kristen: how hot was it yesterday from a global sense? >> the average temperature of the whole world yesterday was just about 63 degrees. that does not sound so hot. remember, that has places like the southeast that are really baking. it also has antarctica in the whole summer -- southern hemisphere. this is really remarkable that we are seeing global highest temperature ever. kristen: met 63 degrees is how much higher comparatively to 30 years ago, 40 years ago? chris: the whole world has warmed by about two degrees. the record temperature had been pretty close to this. it had been within a few tenths of -- few tenths of a you can think of these record temperatures as a strong exclamation point on the idea that quibble warming is occurring. kristen: can i ask you quickly before we move further, why is this an unofficial record? how is it measured? chris: this measurement is taken from satellites that cover the whole world every