To the editor:
In a previous letter (January 28), I asked Mr. Wilkinson, “if human activities are not responsible for this warming [global surface warming since 1900], then what is?”
In a reply published February 6, Mr. Wilkinson listed some of the natural factors that influence Earth’s surface temperatures—Earth’s distance from the sun and the tilt of its orbit, volcanic eruptions, and variations in solar intensity.
These aren’t sufficient to answer my question. Earth’s distance from the sun and the tilt of its orbit haven’t changed significantly since 1900, volcanic eruptions have only cooled the Earth for a few years after they occurred, and solar activity has been declining since 1960. If these were the only influences, our climate should have cooled slightly since 1900.
Instead it has warmed by about 2°F. Scientists of the 19th century, motivated only by curiosity, showed that greenhouse gases—generated by burning fossil fuels—can fully explain today’s warming.
Mr. Wilkinson is correct in pointing out that Earth’s internal heat sources are very slowly decreasing, but that has no relevance to Earth’s surface temperature, because heat from the interior is a negligible fraction (0.03%) of heat coming from the sun (https://en.wikipedia.org/wiki/Earth%27s_energy_budget).
Mr. Wilkinson, you and I may enjoy exchanging letters to the editor, but it seems to me that we’re not making progress toward mutual understanding. I wish to invite you to have dinner with me, at my expense, some time in the near future, so that we can discuss climate science at greater length than permitted by the 300-word limit on letters to the editor. Please send me an e-mail message (joel.huberman@gmail.com) to let me know some dates and times that would be convenient for you.
Joel Huberman
Peterborough