2020 Wasn’t All Bad: There’s Good News About Climate Change

Two important climate stories have somehow evaded media attention. The first is that the authoritative International Energy Agency now recognizes that the high-emissions (and therefore high-warming) scenarios associated with future energy use are flat-out wrong, and the second is that global greening is fighting global warming.

The only real attention that has been paid to the IEA’s bombshell is from University of Colorado’s Roger Pielke, who notes that “thousands” of alarmist articles in the scientific literature now need major revisions (or retraction?). This is a problem because that literature forms the core of the most recent (2018) United States “National Assessment” of climate change effects, a sort of biblical resource for policymakers and the media.

In its revelation, the IEA relies heavily on a withering article by University of British Columbia’s Justin Ritchie in the journal Energy, showing that the United Nation’s future energy use scenarios generally employ what he calls a “return to coal hypothesis,” in which coal use expands dramatically to the year 2100. The high-end scenario used by the U.N.’s Intergovernmental Panel on Climate Change simply ignores the rapid fuel-switching that is occurring as hydrofractured natural gas displaces coal for electricity generation, especially in the U.S.

Yet, the panel’s future energy consumption model producing the greatest warming is based upon the primitive notion that oil will soon be depleted and there will be a massive switch to coal, as Ritchie notes.

In its 2019 “World Energy Outlook” report, the IEA issued an updated suite of emissions projections, which are much lower than almost every scenario in both the most recent (2013) Intergovernmental Panel on Climate Change report and the next one due out in 2021.

The 2013 report specifies a range of future emissions, but the scientific community pays undue attention only to the highest one. IEA says we are on an emissions path that will produce less than half of the high-end warming, around 2.5 degrees Celsius this century. Most people, myself included, think that a 5 degrees Celsius warming this century is surely likely to cause major problems next century, as the year 2100 is not a magic point in which warming suddenly stops.

But the 2.5 degree Celsius estimate is likely too high because it uses the default assumptions in the widely employed Model for the Assessment of Greenhouse-gas Induced Climate Change. One of these assumptions is that the “sensitivity” of global surface temperature (the amount of warming calculated for doubling atmospheric carbon dioxide) is 3 degrees Celsius. Recent analyses using satellite data or observations of temperature and radiation changes yield sensitivities about half of that, which means the actual increases this century are likely to be much lower than even the IEA’s projection.

Read the full article at Washington Examiner.