Science has been an unreliable indicator of global warming for over 30 years

The Hill:

“Science tells us we have nine years before the damage is irreversible,” Joe Biden declared last week, echoing Rep. Alexandria Ocasio-Cortez’s (D-N.Y.) claim 18 months ago that the world would end in 12 years unless climate change was addressed. Pledging “drastic action,” the Democrats’ presumptive presidential nominee says he’ll spend $1.7 trillion so that the United States can cut net greenhouse-gas emissions to zero by 2050.

Biden’s and Ocasio-Cortez’s doomsday remarks both refer to the 2018 special report of the Intergovernmental Panel on Climate Change (IPCC) on the impact of global warming of 1.5 degrees Celsius above pre-industrial levels. That report can now be seen as the most successful bait-and-switch of the 21st century.

In 2015, many national governments, including the United States under the Obama administration, signed on to the Paris Agreement and its aim of “pursuing efforts” to limit the rise in global temperature to 1.5°C and to reach “net zero” – a balance between greenhouse-gas emissions produced and emissions taken out of the atmosphere – sometime in the second half of the century. Three years later, the IPCC produced its 2018 report, bringing forward the net-zero deadline to 2050. At the same time, it declared that greenhouse-gas emissions must be cut by 40 percent by 2030, thereby setting in motion the doomsday timetable touted by climate alarmists.

The science in the report is pretty crude. In essence, the IPCC concluded that the climate impacts of limiting global warming to a 2°C rise are greater than a 1.5°C rise. That’s hardly rocket science, or even climate science. Far more important is what the IPCC did and didn’t do. It didn’t look at the costs of working toward net zero and weigh them against the putative climate benefits. In fact, it barely looked at the costs of net zero at all.

The few estimates that the IPCC does provide should give any but the most fanatical climate advocate pause. A carbon tax instituted to meet the 1.5°C limit would have to be between 10 and 20 times higher than for a 2°C limit and require a tax of up to $6,050 per metric ton. This compares to the $92 for the undiscounted value of the Social Cost of Carbon estimated by the Obama administration. The Social Cost of Carbon aims to identify the net damage caused by each additional ton of carbon dioxide. It also equates to the benefit of reducing emissions by the same amount.

Thus a $6,050 carbon tax to meet Biden’s net-zero goal would be set at a level more than 60 times the hypothetical climate benefits — and that’s assuming China and other large emerging economies cut their emissions too. Seen this way, it’s hard to escape the conclusion that net zero is a form of climate sadism, especially on the middle class and the less well-off.
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The projections of climate change doomsday have been as unreliable as the projections on Covid-19.  They always seem to be about 10 years from whatever the current date is.  Meanwhile, Trump has gone the opposite route of the Democrats and the air is cleaner and we are not on the hook for what other countries do.