It’s important to deconstruct this study because it is touted in the press as silencing “Climate Deniers” and as giving scientific proof of the greenhouse gas effect, once and for all. For example, a CBC article said this:
“A recent experiment at the Lawrence Berkeley National Laboratory in California has directly measured the warming effect of our carbon emissions, using data from instruments that measure the infrared radiation being reflected back to the ground by the atmosphere – the so-called greenhouse effect.
They found that the amount of radiation coming down increased between 2000 and 2010 in step with the rise of carbon dioxide in the atmosphere. So, the effect is real. And since we are continuing to increase our carbon emissions, change will continue to happen, like it or not, both warm and cold.”
The media was agog over this paper, saying that it measures the warming effect of CO2 in the atmosphere, and is proof of the greenhouse gas effect.
This paper claims to prove rising CO2 in the atmosphere increases down-welling infra-red radiation (DWIR), thereby warming the earth’s surface. The claim is based on observations from 2 sites, in Alaska and Oklahoma. Let’s examine the case made.
Observation: In Alaska and Oklahoma CO2 and DWIR are both increasing.
Claim: Additional CO2 is due to fossil fuel emissions.
Claim: Higher DWIR is due to higher CO2 levels.
Claim: Global DWIR is rising.
Claim: Global surface temperatures are rising.
LL Conclusion: Fossil fuel emissions are causing Global surface temperatures to rise
There are several issues that undermine the report’s conclusion.
Issue: What is the source of rising CO2?
Response: Natural sources of CO2 overwhelm human sources.
The sawtooth pattern of seasonal CO2 concentrations is consistent with release of CO2 from the oceans. Peaks are in March when SH oceans are warmest (60% of world oceans), and valleys are in September when NH oceans are warmest. In contrast biosphere activities peak in January in SH and July in NH.
CO2 content of the oceans is 10 times that of the atmosphere, resulting in the sawtooth extremes. Human emissions are ~5 to 7 Gigatons compared to ~150 Gigatons from natural sources.
Issue: What is the effect of H2O and CO2 on DWIR?
Response: H2O provides 90% of IR activity in the atmosphere.
The long term increase in DWIR can be explained by increasing cloudiness, deriving from evaporation when the sunlight heats the oceans. A slight change in H2O vapor overwhelms the effect of CO2 activity, and H2O varies greatly from place to place, while the global average is fairly constant.
Issue: What is the global trend of DWIR?
Response: According CERES satellites, DWIR has decreased globally since 2000, resulting in an increasing net IR loss upward from the surface.
Globally, Earth’s surface has strongly strengthened its ability to cool radiatively from 2000 to 2014 (by about 1.5 W/m2 or ~1 W/m2 per decade) according to CERES. The increased upward heat loss from the surface is matched by decreasing trend of DWIR globally. And this is in spite of significantly increasing atmospheric content of both CO2 and H2O (WV & clouds) + allegedly rising temps since 2000.
The rise in CO2 is almost all from natural sources, not fossil fuel emissions.
IR activity is almost all from H2O, not from CO2.
Global DWIR is lower this century, and the surface heat loss is less impeded than before.
Global surface temperatures are not rising with rising fossil fuel emissions.
In fact, you need only apply a little critical intelligence to this paper, and it falls like a house of cards. Are there no journalists with thinking caps allowed to write about this stuff?