3°C with a probable error of ± 1.5°C." This estimate of climate sensitivity has been essentially unchanged for over four decades, e.g., the IPCC Fourth Assessment Report (2007) says that "equilibrium climate sensitivity is likely to be in the range 2°C to 4.5°C, with a best estimate value of about 3°C. It is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement with observations is not as good for those values." In 2019 climate scientists celebrating the 40th anniversary of the Charney report said "In retrospect, the Charney report seems like the scientific equivalent of the handwriting on the wall...Their warning was accurate and remains more relevant than ever." Centenary celebration In February 2018, MIT held a symposium, named MIT on Chaos and Climate, in honor of the 100th anniversary of the birth of Charney and Edward Lorenz. The two-day event featured presentations from world-renowned experts on the many scientific contributions that the two pioneers made on the fields of numerical weather prediction, physical oceanography, atmospheric dynamics, and experimental fluid dynamics, as well as the personal legacy they left behind of integrity, optimism, and collaboration. In one presentation, Joseph Pedlosky, scientist emeritus at the Woods Hole Oceanography Institute and world leader in physical oceanography, said this of his friend and mentor Jules Charney: "It's fair to say that Jule Charney turned the mystery of the erratic behavior of the atmosphere into a recognizable–although very, very difficult–problem in fluid physics. I would like, however, to talk today about Jule's more personal and I think equally vital contribution to our field, in terms of the inspiring generosity of spirit he showed that advanced the atmosphere of collaborative collegiality in our field. He set a standard for personal and scientific integrity that I think is often overlooked but of exceptional importance." A video produced for the event highlights the indelible mark made by Charney and Lorenz on MIT and the field of meteorology as a whole. Honors and awards 1937 Elected to Phi Beta Kappa. 1961 Awarded the Symons Gold Medal of the Royal Meteorological Society. 1964 Awarded the Carl-Gustaf Rossby Research Medal of the American Meteorological Society, for research that "led to a more fundamental understanding of the atmosphere's general circulation, hydrodynamical instability, the structure of hurricanes, the dynamics of ocean currents, the propagation of wave energy and many other aspects of geophysical fluid