Paper shows a high negitive forcing from human activity

[Tim the plumber]

A peer reviewed paper that provides support to skeptics! And it's in Science.

 

Among all cloud-aerosol interactions, the invigoration effect is the most elusive. Most of the studies that do suggest this effect link it to deep convective clouds with a warm base and cold top. Here, we provide evidence from observations and numerical modeling of a dramatic aerosol effect on warm clouds. We propose that convective-cloud invigoration by aerosols can be viewed as an extension of the concept of aerosol-limited clouds, where cloud development is limited by the availability of cloud-condensation nuclei. A transition from pristine to slightly polluted atmosphere yields estimated negative forcing of ~15 watts per square meter (cooling), suggesting that a substantial part of this anthropogenic forcing over the oceans occurred at the beginning of the industrial era, when the marine atmosphere experienced such transformation.

 

I don't have a subscription to science so I am unable to read the whole paper, I may have to visit my local library.

 

-15 Wm^-2 seems a lot. I am presuming that this figure would be fairly localized.

 

If anyone can post more of the paper without infringing copy right that would be good.

 

The world must move to nationalize scientific journals. The content has already been paid for by us all in our taxes to fund the research!

[John Cuthber]

"Among all cloud-aerosol interactions, the invigoration effect is the most elusive"

Because it is small, and largely overturned by the other effects.

"a substantial part of this anthropogenic forcing over the oceans occurred at the beginning of the industrial era"

So, it's not contributing to recent changes.

[swansont]

 

The world must move to nationalize scientific journals. The content has already been paid for by us all in our taxes to fund the research!

 

!

Moderator Note

Discussion on this particular topic has been split http://www.scienceforums.net/topic/83613-paywalled-science-journals-split-from-negative-forcing-from-human-activity/

 

"a substantial part of this anthropogenic forcing over the oceans occurred at the beginning of the industrial era"

So, it's not contributing to recent changes.

 

Indeed. "A transition from pristine to slightly polluted atmosphere yields estimated negative forcing of ~15 watts per square meter (cooling)"

 

We no longer have a pristine or slightly polluted atmosphere.

[billiards]

"Among all cloud-aerosol interactions, the invigoration effect is the most elusive"

Because it is small, and largely overturned by the other effects.

Where do you get that from?

 

"a substantial part of this anthropogenic forcing over the oceans occurred at the beginning of the industrial era"

So, it's not contributing to recent changes.

I don't buy that. You're assuming that nature does not flush out aerosol.

 

The real significance of that statement is expressed in the conclusions of the paper:

 

If this is true, it means that the preindustrial globe should be considered differently from today’s globe. At least over the oceans, the coverage of warm clouds should be regarded as having been much smaller than it is today.

So it has major implications for palaeo-climate modelling.

[John Cuthber]

Where do you get that from?

 

 

I don't buy that. You're assuming that nature does not flush out aerosol.

 

 

Why else would the effect be elusive?

I'm not making that assumption. I'm assuming that pollution is ongoing. It is, so that's a fair assumption.

 

In any event, what you "buy into" doesn't change things.

Edited June 8, 2014 by John Cuthber

[billiards]

Why else would the effect be elusive?

Because it's part of a complex system and is difficult to isolate.

 

I'm not trying to be antagonistic, I just wanted to know your source.

[John Cuthber]

I don't have a source. To me it's obvious that if, even after decades of research into the effects of pollution on climate, it's because it isn't a big effect and it's swamped by others.

[overtone]

 

 

A peer reviewed paper that provides support to skeptics!

Why does the discovery of yet another negative anthropogenic forcing factor provide "support to "skeptics"?

 

Nobody has ever claimed that every single anthropogenic influence on the climate or weather was a positive contribution to global warming. What else would one be skeptical of, here?

 

 

If this is true, it means that the preindustrial globe should be considered differently from today’s globe. At least over the oceans, the coverage of warm clouds should be regarded as having been much smaller than it is today.

So it has major implications for palaeo-climate modelling.

Quite possibly. Especially the role of volcanic aerosols. So?

[Wild Cobra]

A peer reviewed paper that provides support to skeptics! And it's in Science.

 

 

I don't have a subscription to science so I am unable to read the whole paper, I may have to visit my local library.

 

 

I hope nobody minds if I read and respond to some older threads.

 

I haven't read this yet, but will. When you don't have a subscription, you can often find articles without the paywall if you search the doi number. I searched DOI: 10.1126/science.1252595 and found the full article:

 

http://www.see.ed.ac.uk/~shs/Climate%20change/Climate%20model%20results/Koren%20invigoration.pdf