Citizen Scientist Willis Eschenbach is a prolific poster on climate issues at Watts Up With That. In a New Years post of reflection on where we are in climate science and where we need to go, Willis has posted a number questions; what we do not know now, or know in the future, with a list of his most important questions. For those of you who are not regular WUWT reader I am posting Willis questions for you thoughts and comments
With that as a prologue, let me give at least a partial list of what we don’t know about the climate. Now, bear in mind that I’m not saying we don’t have theories about any number of these questions. Everyone has theories about some or all of these unanswered puzzles, including myself. But there is no agreement, no so-called “consensus”, about the following matters:
WHAT WE DON’T KNOW ABOUT THE PAST AND PRESENT
• Why the earth has been generally cooling since we came out of the last ice age.
• Why the earth generally cooled from earlier in the millennium to the “Little Ice Age” in the 1600-1700s
• Why the earth generally warmed from the “Little Ice Age” in the 1600-1700s to the present.
• Why the warming of 1910-1940 was as large and as fast as the warming of 1975-1998.
• Why the warming that started in 1975 plateaued in the last couple decades.
• What the current generation of climate models are missing that made them all wrong about the current plateau.
• Why there has been no increase in extreme weather events despite a couple of centuries of warming.
• Why the albedo of the northern hemisphere is the same as the albedo of the southern hemisphere, year after year, despite radically different amounts of ocean and land in the two hemispheres.
• Why there has been no acceleration of sea level rise despite numerous predictions that it would occur.
WHAT WE DON’T KNOW ABOUT THE FUTURE
• Whether the earth will warm over the next decade.
• Whether the earth will warm over the next century.
• What the climate of 2050 or 2100 will be like. Wetter? More windy? More droughts? Calmer? More hurricanes? Fewer tornadoes? We don’t have a clue.
• Whether a couple of degrees of warming would be a net bonus, a net loss, or a catastrophic Thermageddon.
• Whether predicting future climate is a “boundary problem”.
• If predicting future climate is a boundary problem, what the boundaries might be and what their future values might be.
• Whether the evolution of the climate is predictable even in theory over anything but the short term.
THE IMPORTANT QUESTIONS
• Why the system is so stable in the very short term (decadal), e.g. the net top-of-atmosphere (TOA) imbalance hasn’t varied by much more than half a watt per square metre over the last 14 years of the CERES records.
• Why the system is so stable in the short term (centuries), e.g. a variation in surface temperature of only ± 0.1% over the 20th century.
• Why the system is so stable in the longer term (millennia), e.g. a variation in surface temperature of only ± 0.5% over the Holocene.
• Why the system is so stable in the even longer term (a million years), e.g. a variation in surface temperature over the period of the ice ages of only ± 1% over the last million years.
• Why the system is so stable in the longest term (a half billion years), e.g. the sun has increased in strength by 5% over that period, an increase of about 13 W/m2. According to the accepted theory such an increase in forcing should have led to a surface temperature increase of 13°C over that period … why didn’t that increase happen.
• Why we are no closer to getting a value for the so-called “climate sensitivity” than we were thirty years ago. After uncountable hours of human labor, after huge increases in the size and complexity of our models, after unprecedented increases in computer power, after millions and millions of dollars spent on the problem, the error bounds on the answer have not narrowed at all … why not?
Your thoughts on the these questions by Citizen Scientist Willis Eschenbach are most welcome, here or at WUWT.