Greta Thunberg (klimataktivist)

Timothy Osborn, Professor, University of East Anglia, and Director of Research, Climatic Research Unit:
The unpublished paper by Kauppinen & Malmi is deeply flawed and the claims that (1) CO2 has caused only 0.1 degC of warming and that (2) only 10% (0.01 degC) of this warming is from human activity are both unsupported claims.

The paper should not be relied upon.

Their claims are based on a chain of reasoning with multiple flaws:
(1) They claim that climate models cannot be relied upon but do not demonstrate this.
(2) They instead make a new climate model (despite this being in contradiction of (1)).
(3) Their new climate model is unvalidated. It is based upon datasets of cloud and humidity without any sources given and which are not up-to-date. They provide no assessment of the accuracy of the data used—these variables are very difficult to measure on a global basis over the time period used. No physical basis is given for their new climate model (e.g. no process is given for how higher relative humidity can make the globe cool).
(4) They fail to consider cause and effect. For example, they assume without any support that a decrease in relative humidity is natural. They give no reasons why it would have decreased. They fail to consider whether climate change could have caused relative humidity to change.

(5) They state without any support that most of the atmospheric CO2 increase is due to emissions from the oceans. They ignore anthropogenic CO2 emissions which are more than large enough to explain the full increase. They ignore observational evidence that shows that the oceans are net sinks of CO2 at present, not net sources.
(6) They dismiss the entire body of climate science—especially that there is a significant greenhouse effect—and instead cite their own work (unpublished or published in journals outside the field).