Climate Change
We’d like to begin by sharing with you the latest report from Intergovernmental Panel on Climate Change (IPCC), a United Nation organization in charge of advancing scientific understanding of human-caused climate change. It just released its Synthesis Report for its sixth Assessment Report (AR6) (IPCC, 2023) and its Summary for Policymakers (IPCC, 2023). Report is included here.
The Synthesis Report is based on the content of the three Working Groups Assessment Reports: WGI – The Physical Science Basis (2021), WGII – Impacts, Adaptation and Vulnerability, WGIII – Mitigation of Climate Change, and the three Special Reports: Global Warming of 1.5°C, Climate Change and Land, The Ocean and Cryosphere in a Changing Climate. We share with you the Physical Science Basis report (2021) here.
These reports conclude that “it is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred.” Human activity is mostly to blame for the current climate warming. AR6 specifies that the temperature of the planet’s surface increased by 1.09 [0.95-1.20] °C from 1850–1900 to 2011–2020, and that human activities should have induced a warming of about 1.07 [0.8-1.3] °C. Natural warming caused by the Sun and volcanoes was estimated to be negligible, that is between -0.1 °C and +0.1 °C (Summary for Policymakers, A.1.2 e A.1.3). Hence, according to the IPCC, anthropogenic (human-caused) greenhouse gas emissions and other man-induced climate forcings would be accountable for nearly all (that is, 100%) of the global warming observed between 1850 and 2020.
IPCC also states that: “The scale of recent changes across the climate system as a whole – and the present state of many aspects of the climate system – are unprecedented over many centuries to many thousands of years. Additionally, “human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened since AR5.”
IPCC reports that these assessments and predictions are obtained by using specific climate models. These models are those of the World Climate Research Programme (WCRP), Coupled Model Intercomparison Projects’ Global Circulation Model (GCM) of Phase 6 (CMIP6) (Eyring et al., 2016).
The Question of Consensus
There are those who disagree with IPCC’s assessments. One area of disagreement is it’s scientific basis and the climate models upon which IPCC’s predictions are made.
One such scientists is Dr. Nicola Scafetta, Professor of Physics of the Atmosphere and Climatology at the University of Napoli Federico II. Dr. Scafetta wrote an article April 2023 titles “Interpretation of climate change: from CO2-based to astronomical oscillations-based models”. Climate models must include many factors about earth’s climate, much of which we do not understand. He asserts that UN’s climate models are inaccurate in 3 main areas of uncertainty: it’s unequal inclusion of urban heat sink temperatures, its minimal inclusion of the sun’s influence on earth climate,and equilibrium climate sensitivity was significantly lower than what IPCC’s Coupled Model Intercomparison Project (phase 6) (CMIP6) predict and equilibrium climate sensitivity was significantly lower than what IPCC’s Coupled Model Intercomparison Project (phase 6) (CMIP6) predict.
IPCC claims 97% of the scientific community agree on anthropogenic Climate Change. Unforunately, there are reports to the contrary that 97% of scientists agree with the IPCC’s conclusions that humans are responsible for nearly 100% of the warming observed from 1850–1900 to date. A 2016 National Survey of American Meteorological Society Member Views on Climate Change: Initial Findings. George Mason University, Fairfax, VA: Center for Climate Change Communication (by Maibach, E., Perkins, D., Francis, Z., Myers, T., Englbom, A., et al.) concludes that just 29% of more than 4000 American meteorologists believed that human activity had contributed between 81 and 100 percent of the global warming that has occurred from 1965 to 2015.