Claim reviews

Natural variability can not explain modern global warming, as Heartland Institute report claims
CLAIM
Neither the rate nor the magnitude of the reported late twentieth century surface warming (1979–2000) lay outside normal natural variability.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 30 May 2017

VERDICT

A lull in solar activity would have little effect on global temperatures; claims of “global cooling” are not based on science
CLAIM
Forward projections of solar cyclicity imply the next few decades may be marked by global cooling rather than warming, despite continuing CO2 emissions.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 30 May 2017

VERDICT

Global warming has not “ceased”, as Heartland Institute report falsely claims
CLAIM
global warming ceased around the end of the twentieth century and was followed (since 1997) by 19 years of stable temperature

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 29 May 2017

VERDICT

CO2 is a greenhouse gas that caused warming during past climate changes, notably as a feedback amplifying other factors
CLAIM
Increases in atmospheric CO2 followed increases in temperature. Therefore, CO2 levels could not have forced temperatures to rise.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 26 May 2017

VERDICT

Heartland Institute report’s claim that climate models are too sensitive to CO2 does not reflect evidence
CLAIM
[climate models] systematically over-estimate the sensitivity of climate to carbon dioxide ... and modelers exclude forcings and feedbacks that run counter to their mission

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 23 May 2017

VERDICT

Heartland Institute report incorrectly claims no evidence of human impacts in melting ice
CLAIM
Melting of Arctic sea ice and polar icecaps is not occurring at ‘unnatural’ rates and does not constitute evidence of a human impact on the climate.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 17 May 2017

VERDICT

Global sea level rise is accelerating, despite Heartland Institute report’s claims otherwise
CLAIM
Best available data show sea-level rise is not accelerating. Local and regional sea levels continue to exhibit typical natural variability—in some places rising and in others falling.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 08 May 2017

VERDICT

The Sun cannot explain recent global warming, contrary to what Heartland Institute report claims
CLAIM
Solar forcings are not too small to explain twentieth century warming. In fact, their effect could be equal to or greater than the effect of CO2 in the atmosphere.

SOURCE: Craig Idso, Robert Carter, S. Fred Singer, Heartland Institute

Published: 03 May 2017

VERDICT

Climate sensitivity estimate given in Heartland Institute’s report is misleading
CLAIM
Doubling the concentration of atmospheric CO2 from its pre-industrial level, in the absence of other forcings and feedbacks, would likely cause a warming of ~0.3°C to 1.1°C

SOURCE: Craig Idso, Robert Carter and S. Fred Singer, Heartland Institute

Published: 02 May 2017

VERDICT

In CNN interview, William Happer incorrectly claims temperatures don’t match climate model projections
CLAIM
The temperature is not rising nearly as fast as the alarmist computer models predicted. You know, it’s much, much less, factors of 2 or 3 less.

SOURCE: William Happer, CNN

Published: 25 Apr 2017

VERDICT