Our current lack of understanding of the Earth’s climate system does not allow us to determine reliably the magnitude of climate change that will be caused by anthropogenic CO2 emissions, let alone whether this change will be for better or for worse.
The major errors in the models (we think) are related to not accounting fully for the sun's energy, and not modeling clouds accurately. There is very high confidence that uncertainties in cloud processes explain much of the spread in modeled climate sensitivity.
Even the relationship between CO2 concentrations and temperature is complicated.
The glacial record shows geological periods with rising CO2 and global cooling and periods with low levels of atmospheric CO2 and global warming. According to a 2001 article in Climate Research by astrophysicist and geoscientist Willie Soon and his colleagues, “atmospheric CO2 tends to follow rather than lead temperature and biosphere changes.”
A large proportion of the warming that occurred in the 20th century occurred in the first half of the century, when the amount of anthropogenic CO2 in the air was one quarter of the total amount there now. The rate of warming then was very similar to the rate of warming recently. We can’t have it both ways. The current warming can’t be unambiguously caused by anthropogenic CO2 emissions if an earlier period experienced the same type of warming without the offending emissions.
Even so, the political narratives and trans-national push for net-zero emissions have only strengthened in the face of this growing uncertainty.
Over the last 14 years Willie Soon, a researcher at the Harvard-Smithsonian Centre for Astrophysics, received a total of $1.25m from Exxon Mobil, Southern Company, the American Petroleum Institute (API) and a foundation run by the ultra-conservative Koch brothers
There were no grants from Nasa, the National Science Foundation or the other institutions which were funding his colleagues at the Center for Astrophysics. According to the documents, his work was funded almost entirely by the fossil fuel lobby.
The major errors in the models (we think) are related to not accounting fully for the sun's energy, and not modeling clouds accurately. There is very high confidence that uncertainties in cloud processes explain much of the spread in modeled climate sensitivity.
Even the relationship between CO2 concentrations and temperature is complicated.
The glacial record shows geological periods with rising CO2 and global cooling and periods with low levels of atmospheric CO2 and global warming. According to a 2001 article in Climate Research by astrophysicist and geoscientist Willie Soon and his colleagues, “atmospheric CO2 tends to follow rather than lead temperature and biosphere changes.”
A large proportion of the warming that occurred in the 20th century occurred in the first half of the century, when the amount of anthropogenic CO2 in the air was one quarter of the total amount there now. The rate of warming then was very similar to the rate of warming recently. We can’t have it both ways. The current warming can’t be unambiguously caused by anthropogenic CO2 emissions if an earlier period experienced the same type of warming without the offending emissions.
Even so, the political narratives and trans-national push for net-zero emissions have only strengthened in the face of this growing uncertainty.
Why is that?