Michael Mann's Blog
The letter below was submitted to the New York Times on 3/26 in response to their 3/25 article on the recent National Academy of Sciences "Solar Geoengineering" report (I commented on the report here last week). The Times has evidently declined to run the letter, so I am publishing it myself here.
The U.S. National Academy of Sciences has published a new report ("Reflecting Sunlight") on the topic of Geoengineering (that is, the deliberate manipulation of the global Earth environment in an effort to offset the effects of human carbon pollution-caused climate change).
Two decades ago, in an interview with science journalist Richard Kerr for the journal Science, I coined the term the "Atlantic Multidecadal Oscillation" (the "AMO" for short) to describe an internal oscillation in the climate system resulting from interactions between North Atlantic ocean currents and wind patterns. These interactions were thought to lead to alternating decades-long intervals of warming and cooling centered in the extratropical North Atlantic that play out on 40-60 year timescales (hence the name).
As some readers will know, I happen to have been on sabbatical in Australia these last past months. I came there to study the impact of climate change on extreme summer weather events with a specific focus on Australia. Only to arrive in mid December just in time to encounter the most profound example on record.
In light of recent social media posts and conversations I've had with colleagues, I want to take this opportunity to make a statement about the importance of lifting the voices of women, people of color, and other voices that have been marginalized in the world of science communication, including the discourse over climate change.
Summer 2018 saw an unprecedented spate of extreme weather events, from the floods in Japan, to the record heat waves across North America, Europe and Asia, to wildfires that threatened Greece and even parts of the Arctic. The heat and drought in the western U.S. culminated in the worst California wildfire on record. This is the face of climate change, I commented at the time.
A new study just out in Science attributes the unusually active 2017 Atlantic hurricane season to tropical Atlantic warming. Furthermore, it attributes that warmth to human-caused climate change (a combination of increasing greenhouse gas concentrations and sulphate "aerosols" from industrial pollution).
Two years ago, in the home stretch of our last presidential election, Washington Post cartoonist Tom Toles and I published a book about climate change denial (“The Madhouse Effect: How Climate Change Denial Is Threatening Our Planet, Destroying Our Politics, and Driving Us Crazy”). Denialism was still a major problem, we argued.
Fixing the headline would be simple (just remove “but Not”), but the op-ed itself is irreparable, constituting little more than a litany of denialist talking points. No, ice is not accumulating on Earth—it is melting.
With a climate change denier in the White House, climate denialism has reached a new low point in America. Indeed, my co-author Tom Toles and I have devoted a whole new chapter to the matter ("Return to the Madhouse: Climate Change Denial in the Age of Trump") in the new paperback edition of our book The Madhouse Effect (now available for pre-order).
There is a quantity known as the "Equilibrium Climate Sensitivity" or "ECS" that serves as a traditional measure of the warming effect of greenhouse gases. The ECS characterizes the total warming we would expect from a doubling of the concentration of greenhouse gases (e.g. from the pre-industrial level of 280 parts per million to the 560 ppm level that would be expected by the middle of this century if we continue with the unabated burning of fossil fuels) once the climate system fully adjusts to this increase.