In this newer paper, they reported that they tested two different levels of extra thermal radiation. You might think they would have tested something more realistic, like +3W/m².
1/6. From measurements of downwelling LW IR, 342 W/m² is a reasonable, approximate estimate of downwelling LW IR radiation averaged over the entire surface of the Earth.
It's essentially identical to MacCracken's 1985 estimate (which he called "only an approximation"):
(Note: the numbers are percentages.)
The quoted text excerpt is:
“The fluxes of energy within the atmosphere-surface system can be illustrated using an energy balance diagram. Although many measurements have been made at the surface and from satellites, there are still uncertainties of 10-20% in the values of some of the fluxes because of the difficulty of making representative global measurements. In some cases model calculations have been used to generate estimates. The values shown in the diagram in Figure 1.2 are derived from consideration of energy balances prepared by Gates (1979), Liou (1980), and MacCracken (1984), and are only an approximation.”
Source:
M. C. MacCracken and F. M. Luther (Ed.), "Projecting the Climatic Effects of Increasing Carbon Dioxide," United States Department of Energy, DOE/ER 0237, Dec. 1985.
Note that the main source of uncertainty is not that we cannot measure downwelling LW IR. Rather, it is "the difficulty of making representative global measurements." Actual downwelling LW IR fluxes vary wildly with time and location, so finding an accurate global average is problematic, to put it mildly.sealevel.info/MacCracken1985… researchgate.net/profile/Michae…
3/6. Here's the NCA4 version (with my notes about the "radiative imbalance" added). They show downwelling LW IR = 338 to 348 W/m², with a best estimate of 342: sealevel.info/NCA4_global_en…
@joelgombiner @RARohde 1/5》I agree. Without those ice sheets, there's no source for vast influxes of freshwater into the northern North Atlantic, to slow the AMOC.
There are a few key lessons to be learned from Dansgaard-Oeschger events (and D-O #0, a/k/a the Younger Dryas). sealevel.info/learnmore.html…
@joelgombiner @RARohde 2/5》Because D-O terminations had warming trends an order of magnitude faster than current warming, and because nearly all extant species survived those large, sharp warming events, we needn't worry that the current slight warming could cause extinctions. archive.is/aUi9R#selectio…
3/5》Because D-O events only occur during glaciations, and never during interglacials, we can say with confidence that warmer climates are more stable than colder climates.
That might be largely because without the great northern ice sheets, there's nothing which could pour vast quantities of freshwater into the northern North Atlantic, slowing the AMOC.
It's surely also because Planck Feedback is ∝ T⁴, so the warmer the climate gets, the stronger that negative (stabilizing) feedback is.
3/4. The best science shows manmade climate change is modest & benign, and CO2 emissions are beneficial, not harmful. The major harms from CO2 are all hypothetical, and mostly implausible. The major benefits are proven, measured, and very large.
1/11》 Don't believe the Climate Industry propaganda. Here are some academic papers and articles about what fossil fuels, carbon emissions, and #climatechange are ACTUALLY doing to the Earth:
2/11》 Here's a NASA video about it. It's based on measurements, unlike most of the Climate Industry's "climate impact" claims, which are based on dubious modeling and baseless speculation.
3/11》 The CO2 Coalition's website also has many excellent resources to help you learn about this issue:
The CO2 Coalition is an organization of volunteer scientists, dedicated to combating disinformation about CO2 & climate change, and pushing back against the corruption of science for political & pecuniary reasons.
Many of the CO2 Coalition's members are extremely distinguished. Their newest Board Member is Dr. John Clauser, 2022 Nobel Laureate (Physics). co2coalition.org
1/11❯ You've been lied to. The impacts of rising CO2 levels are in both the past and the future, and they are overwhelmingly positive. sealevel.info/learnmore.html…
2/11❯ The fact that elevated CO2 is dramatically beneficial for crops has been settled science for more than a century. This was not the "mid 20th century." sealevel.info/ScientificAmer…
@collapse2050 3/11❯ Thanks, in significant part, to rising CO2 levels, crop yield improvements have outpaced population growth.
1/5. Here's what CO2 emissions and #ClimateChange are actually doing to the world's food supply. sealevel.info/learnmore.html…
2/5. The relationship between food (in)security and CO2 emissions / climate change is that CO2 emissions greatly improve crop yields, improve crops' drought resilience, and improve food security everywhere in the world.