Hey all, I've been a long time lurker, but I've had some rather silly questions I can't seem to get a definitive answer on.
Firstly, it was recently determined that the effect of aerosol masking has been underestimated by double, but I don't see any paper which gives any temperature value as to how much warming has been avoided. This paper: https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4613 says we have avoided 2.6K, this is equivalent to degrees C right? And if this is the case, would that mean that 4C or more is in the cards when we lose aerosol masking?
Also, many this year are saying we will tie 2012 or surpass it, but it seems to my ignorant eyes that the ice is overall much poorer in terms of overall rigidity to even really matter if it does or not, because it seems like so much energy is going into the ice that refreeze will start later and melt will start early next season, with nothing but poor ice. Are any others feeling this way, or would it be too early to speak about?
In the event that we do lose sea ice, it would seem to me that there wouldn't be a rebound of the pack as a whole, but rather there would be seasonal diminishing returns of small areas having bits of ice until there is no longer a refreeze. Is this assumption also incorrect?
Finally, to what degree would this bring in terms of warming and how fast do we estimate the warming will occur?
Welcome to the forum.
Far from best qualifies for this but:
easy question first
K is equivalent to degrees C right?
yes.
Says we have avoided 2.6K And if this is the case, would that mean that 4C or more is in the cards when we lose aerosol masking?
If we lost aerosol masking that would be 2.6K and perhaps you are adding 1.5C that seems pretty much unavoidable to get to 4C?
Not sure we are going to lose the masking completely even if we completely give up coal mining there will still likely be other mining and other sources of aerosols. So not sure we will really get the full 2.6K. However increases in GHG while reducing aerosol forcing should be considered highly likely to give a faster rate of temperature rise than GHG increases while aerosols are also increasing.
>effect of aerosol masking has been underestimated by double
I assume this is Rosenfeld et al 2019. I haven't seen much in the way of review that I would trust. I have seen headlines like
We need to rethink everything we know about global warming
New calculations show scientists have grossly underestimated the effects of air pollution
which I don't trust - looks like a clickbait heading to me.
If I read the paper, I wouldn't trust me to critique the paper, but I will point out:
The paper's title is
Rosenfeld, D.; et al. (2019): Aerosol-driven droplet concentrations dominate coverage and water of oceanic low level clouds
looks like it has appeared in Science so very reputable journal and if I had criticisms of the paper definitely trust the peer review rather than me.
However, note that this paper is only about part of the effects of aerosols.
Second it is one paper.
I am noting these things because there are other ways to assess aerosol effects. For example volcanoes have massive effect on aerosol levels compared to what humans do and we can see the temperature effect. From one eruption, you couldn't tell much but from 3 or 4 significant volcanoes in the last several decades you can start to judge if the models have aerosols about right. If the models are way out, there would be noticeable problems with other efforts at assessing aerosol effects.
I am not saying it is impossible that ghg warming and aerosol cooling have both been underestimated such that the errors largely cancel out. However if we were way out, it would likely show up elsewhere.
With that size difference, a more likely possibility might be that we have underestimated aerosol effects in one place but also overestimated them somewhere else.
'rethink everything we know about global warming' just isn't the way things work. It is not a long chain that is only as strong as the weakest link. It is much more like a mesh where even if you cut one wire then not much happens other than nearby wires taking up some of the strain.
Sorry this is not a more expert answer.