http://www.nature.com/nclimate/journal/v6/n8/fig_tab/nclimate3004_F1.html

I've been looking at Zhu et al and have noticed a couple of points.

Firstly, my suggestion that the net effect of extra CO2 in arid/ semi-arid areas is negative. Look at the maps in Figure 1.

The most well defined arid area, Australia, shows pale green or yellow in all maps and definitely yellow in GLAS. Leaf area has reduced. I think Matt Ridley is mistaken.

Now look at Figure 1d, the trend probability distributions. The modes, the maximum probability values, are what I am looking at.

Both GIMMS and GLOBEMAP show no trend at all. AVG shows a trend of 0.002. That is an increase of 20cm^2/m^2/year, two postage stamps.
Since a typical crop will have a leaf area around 10,000 sq.cm, that is an annual increase of 0.2%,

Only GLAS shows significant change, a trend of 0.025. This is an increase of 250sq.cm, half a sheet of A4 paper, and an annual increase of 2.5%.

With two out of four sensors showing no trend and only one showing a significant change, Zhu et al is very weak evidence of greening. Goldany and Ridley are making a propoganda mountain out of a greening molehill.

A brighter iris gleams from within the greenished love.
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I have had a quick look at the title and list of authors, of this paper that was received by Nature and Climate Change in June 2015 but not accepted until March 2016.

I do not recognise any of the names of the numerous authors, as being associated with the normal Hockey Team suspects of Climate Science. This is probably a good sign.

The paper took NINE months to get through Peer Review. This suggests that some at Nature and Climate Science were keen that this paper should not pass Peer Review. This is probably a good sign.

The paper has attracted sufficient concern amongst the Concenserati, that a critical post/thread has been started here. This is probably a good sign.

As Climate Science found CO2 guilty, with out trial or evidence, but based on a "hunch" that matched preconceived prejudice, I conclude that Zhu et al is GOOD, based on the logic above, with a high level of confidence (about 97%).

That is how Climate Science works, and normally fails what it doesn't like.

I'm more than a little amused that 'greens' have found a need to be 'anti-green'.

The sun and the biome conspire to almost irreversibly sequester carbon from that same biome. That man has effected a miniscule reversal of that inevitable process would constitute a miracle if it were not so predictable.
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The coccolithophores are already massing a response to our measly meddling; the silting of their bones practically constitutes a condensing of CO2 out of the atmosphere and the oceans.
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NASA is, or was before the climatocracy stepped in, showing that plankton is up in the oceans. That's where the bulk of the biomass exists. The papers claiming that plants don't thrive in the presence of increased CO2 are, to be diplomatic, dubious at best. They are, to be honest, denying the facts. How ironic.

hunter
It's interesting that laboratory experiments show that CO2 is a greenhouse gas and that plants do better in a CO2 enriched environment and that at marginal temperatures for growth a bit of warming helps too. Models show that the polar regions will have greatest warming therefore will get two boosts from increased CO2.

Yet we're supposed to believe increased CO2 is a disaster for plant life and only 250ppm will do.

Entropic man
How does the Australian data correlate with long term (decadal or longer) natural climate cycles? We know that California has had century long dry spells in the past. The ENSO affects both Australia and California so it might be reasonable to investigate Australia's current climate against history before solely blaming CO2 for the current situation?

Loving the fact that all the attribution to CO2 etc is model-based. Some models are better than other, clearly.

I'm still looking for papers on the magnitude of the effect of CO2 and warming on crop yields and nutritional btw, if anyone knows of any, most crops are seeds rather than leaves.

Golf Charlie

The paper has attracted sufficient concern amongst the Concenserati, that a critical post/thread has been started here.

Thank you for the promotion. I was not aware that I was a major player in the climate debate.

Radical Rodent

Research the long term carbon cycle. You will find that carbonate rocks do not permanently sequester carbon dioxide.

Eventually they erode, become marine sediments, subduct and the carbon dioxide returns to the atmosphere via volcanoes.

SandyS

How does the Australian data correlate with long term (decadal or longer) natural climate cycles?

In the short term Australia is affected by ENSO and it's Indian Ocean equivalent. In the long term it is affected by glacial/ interglacial cycles.

Off hand I don't know of any intermediate cycles. Do you have data?

Entropic man: See RR above and note 'almost irreversibly'. That there are massive stores of carbonates and of hydrocarbons testifies to the overall direction of carbon sequestration.

RR, given that the whole climate scare is built on unnecessary fear and misplaced guilt, removing those might give legs to the thought. We've been scammed by ancient mechanisms of the religious shamen. We need not fear the mild warming of which we are capable, and we need not feel guilty about rescuing the plants, and thus the whole biome.

We deserve credit, and it will come; perhaps not before our grandchildren's time, but sometime.
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"....most crops are seeds rather than leaves."
Phil Clarke.9:28 AM
According to the FAO (Food and Agriculture Organization), worldwide, land used as arable (including seed), is 5 million square miles, whereas pasture (leaves, mainly grass), is 13 million square miles.

Heh, we could have pilgrimages to toss rocks into volcanos to pacify the angry plant community.
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Given the necessity of CO2 for life on Earth, persisting intelligent life on earth will eventually derive a means to liberate carbon from carbonates, probably by harnessing sunlight to do so. There is no need for research toward such a method now, thanks to those pesky little hydrocarbons.
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I love a grass sandwich, me.

We know you produce gas, Phil, but please, less of the methane.
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Mark Stevens

One acre of arable cropland can, on average, support 2 people. The crop is eaten directly by people so all the energy from it is available.

Pasture can only to feed animals. 90% of the energy is used by the animals, and only 10% is left to be aten by people.

Thus living on pasture, 10 acres is needed to feed 2 people.

EM, are you now advocating in support of carnivores eating Greens?

I am sure Polar Bears won't be too fussy.

RR, kim. What do you think happens to mountain chains worth of limestones (Alps, Atlas, Dinarides, Zagros, Himalayas, Rockies, Andies) when they erode, weather and dissolve, or when clays, mustones and shales (the most common sedimentary rocks, containing on average 0.5% organic carbon by weight) weather? They release their carbon as carbon dioxide. So no chance whatsoever of plants running out.

Coccolithophores are now stored on some deep ocean floors, but too deep and they dissolve to be recycled.

Time's Arrow is not toward increasing sequestration of carbon.

RR "So, what you are saying is that there may be sources of CO2 other than human consumption of fossil fuels, and release from the biome by human-induced warming."

No I'm not saying that, I'm saying there are definitely sources of CO2 far larger than human activities produce. Much weathering involves life, increases with temperature, rainfall and rain acidity. Much of the increase in atmopheric CO2 will be a by product of increased weathering rates responding to warmer temperatures.

"Do you wonder if the High Priests of Climastrology know about this?"

I was going to suggest a quick read of The Carbon Cycle in Wiki, but it's crap, as were items on the first two Google Pages. Then I remember reading a particularly good coverage in the Science reports of the IPCC. So yes the scientific high priests do know and have spent much treasure quantifying the magnitudes of the fluxes.
Enjoy!

ACK, the existence of large stores of carbonates and hydrocarbons proves the arrow is toward sequestration. CO2 levels in paleontology have a decline curve.

There may well be a point at which release evens out with sequestration, but it will be at a very low level of CO2. I suppose it is possible that plants will evolve to survive at that level.
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Radical Rodent, clearly the EU needs to Capture and Store the Alps. The US can do the Rockies, and South East Asia the Himalayas. It is going to need a lot of concrete though. Maybe we could turn the Great Barrier Reef into an offshore limestone quarry?