Hi JF,
Thanks for that WEF report, I'm looking forward to having a good read! If you don't mind I won't comment until then.

On the subject of CO2 and absorption of IR:
the reason Roberts is wrong is that IR radiation that impinges on the earth is of shorter wavelength (higher energy) on average than the radiation leaving. This means that the outbound radiation is more readily absorbed by CO2 molecules than the incoming stuff.

The reason for the shift in wavelength is simple: the sun is hotter than the surface of the earth and hotter means more energy, means shorter wavelength.

This isn't in doubt. What is still not well understood, although models are constantly improving, is the effect of this increased absorption of low-grade heat on planetary cycles.

JF,
The heat is not coming from the sun, but the earth! The sun shoots light which goes straight through the atmosphere, and then bounces off the earth as heat. That heat is then trapped by the CO2 from escaping as efficiently as it used to. It's like a blanket keeping you warm, but for the whole earth.

"The mechanism by which carbon dioxide traps heat in the atmosphere is commonly referred to as the "greenhouse effect." Stated very simply, carbon dioxide, or CO2, is nearly transparent to the solar radiation emitted from the sun, but partially opaque to the thermal radiation emitted by the earth. As such, it allows incoming solar radiation from the sun to pass through it and warm the earth's surface. The earth's surface, in turn, emitts a portion of this energy upwards toward space as longer wavelength or thermal radiation. Some of this thermal radiation is absorbed and re-radiated by the atmosphere's CO2 molecules back toward earth's surface, providing an additional source of heat energy. Without water vapor, CO2, and other radiatively-active trace gases in the air, the planet's average temperature would be about 34°C cooler than it is at present."
http://www.co2science.org/subject/questions/1998/greenhouse.php

Basically, I wouldn't trust anything someone like Malcolm Roberts said about science. His performance on Q&A was too retarded for words. The radiative forcing of CO2 and how light pierces it but heat cannot is not debatable. It's stuff you look up in science textbooks. *OLD* science textbooks!

J F Aus
Thankyou for the link to the BIQ building. Just as I suspected however the algae does NOT directly warm the building. The algae absorbs solar energy and stores it thus preventing some of the suns heat from warming anything. The energy stored as a residue is harvested as biogas and burnt to warm the building.
That article linked to this below.
"When the sun shines, the algae multiplies as a result of photosynthesis. The system collects the residue, then converts it to biogas, which is burned in a boiler."
https://www.fastcoexist.com/1681728/this-entire-building-is-powered-by-its-algae-filled-walls

To mimic this in the oceans you need to convert the stored energy to heat. Some things that live on the algae will do this to some extent but the overall effect still seems to be cooling as energy sinks to the bottom of the oceans.

Bob Fernley-Jones
Found a great NASA video that shows how Venus is still like a comet in the tail and how holes in the atmosphere are due to there being no magnetic field.
http://youtu.be/9MVRMzmwubM
Seems to me the magnetic field is absent with the oceans just as they are absent on Mars. There is a theory that the earths magnetic field is produced by our oceans.
Velicovsky would have expected Rosseta to find hydro-carbons too. So his theory that some of our so called "fossil fuels" rained in from space is looking better all the time.

Oh J F Aus forgot this one for you.
http://youtu.be/ExOXF1x3N1g

Another way that CO2 helps to cool the planet is the leaky one way diode valve it creates for infra red (UP and out favoured).
Pressure Broadening creates a pyramid of absorbtion bandwidth. The broadening means that at low altitudes a wide bandwith is absorbed by CO2 to be radiated back up but at a high altitude much of this will not be trapped (so to speak) by CO2 having narrow bandwidth and will escape rigt past.
“Atmospheric pressure strongly affects the absorption spectra of gases (through
pressure broadening). This poses a major problem in computing the transfer of IR
radiation through the atmosphere with varying pressure, temperature, and amount
of gases. ”
Also see figure 6.1
http://irina.eas.gatech.edu/EAS8803_Fall2009/Lec6.pdf
More info on that and other broadening.
http://www.phy.ohiou.edu/~mboett/astro401_fall12/broadening.pdf.

Siliggy,

Here are a few things for you to digest and perhaps comment on.

1. Cyanobacteria algae is deemed a bacteria. Some bacteria generates heat such as in compost as you know.
Cyanobacteria algae also feeds on waste.
http://archive.bio.ed.ac.uk/jdeacon/microbes/thermo.htm

2. I think you were AWOL and may have missed links I posted on page 17 of this thread, especially about electricity extracted from algae.
Surely there is heat associated with ocean algae occurring somewhere.
Scroll down here:
http://forum.onlineopinion.com.au/thread.asp?article=18459&page=17

3. If you consider pinpoints of cloud can be seen forming above algae inundated water, surely heat is linked to convection reaching up at least to those pinpoints.

4. As I have said previously, using my hand I can feel warmth in a mat of algae in a pond while there is no apparent similar warmth in water alongside.

5. I agree ocean algae would make water cold lower down due to shade caused by algae at the surface, but if anthropogenic proliferated algae was not there there would be no shade and no cold and no solar energy absorbed and stored in such algae.

6. It has been said to me, quote, " No autotrophic organism can survive without emitting heat as a bi-product of photosynthesis."
True or false?

7. Can anyone give categoric assurance algae MATTER in oceans and lakes does not absorb solar warmth and store it after sundown even for 2 or 3 hours?

Homework:
http://www.edinformatics.com/math_science/how_is_heat_transferred.ht