The Bad Science and Bad Policy at the Heart of the Climate Movement
Sitting in plain sight for more than 30 years
Roger Pielke Jr.
Jul 28, 2025
Climate policy is so easy!
Few people are aware of the fact that “climate change” means very different things in science and in policy. That difference exposes the fundamental incoherence of climate policy, highlighted by the recent rediscovery that there is more to increasing global temperatures than just greenhouse gas emissions.
Remarkably, the Intergovernmental Panel on Climate Change (IPCC) and the U.N. Framework Convention on Climate Change (UN-FCCC, 1992) use different definitions of “climate change.”
The IPCC defines climate change as:
A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use.
Under the IPCC, any change in the statistics of weather, regardless of cause, is thus climate change.
https://rogerpielkejr.substack.com/p/the-bad-science-and-bad-policy-at
