claim: "His [Dr Spencer's] latest research demonstrates that – in the short term, at any rate –  the temperature feedbacks that the IPCC imagines will greatly amplify  any initial warming caused by CO2 are net-negative, attenuating the  warming they are supposed to enhance.
evidence: In 1939, Martin Kamen and Samuel Ruben of the Radiation Laboratory at Berkeley began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research.