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C3 and C4 photosynthesis
#1
Before you yawn and click to another place, you need to get your head around this because it matters. Understand it and you will be ahead of the game:

First a quick cut & paste for the basic background:

The majority of plants and crop plants are C3 plants, referring to the fact that the first carbon compound produced during photosynthesis contains three carbon atoms. Under high temperature and light, however, oxygen has a high affinity for the photosynthetic enzyme Rubisco. Oxygen can bind to Rubisco instead of carbon dioxide, and through a process called photorespiration, oxygen reduces C3 plant photosynthetic efficiency and water use efficiency. 
In environments with high temperature and light, that tend to have soil moisture limitations, some plants evolved C4 photosynthesis. A unique leaf anatomy and biochemistry enables C4 plants to bind carbon dioxide when it enters the leaf and produces a 4-carbon compound that transfers and concentrates carbon dioxide in specific cells around the Rubisco enzyme, significantly improving the plant's photosynthetic and water use efficiency. 
As a result in high light and temperature environments, C4 plants tend to be more productive than C3 plants. Examples of C4 plants include corn, sorghum, sugarcane, millet, and switchgrass. However, the C4 anatomical and biochemical adaptations require additional plant energy and resources than C3 photosynthesis, and so in cooler environments, C3 plants are typically more photosynthetically efficient and productive.





1. Photorespiration is a wasteful pathway that occurs when the Calvin cycle enzyme rubisco acts on oxygen rather than carbon dioxide.

2. 95% of are 3C plants, which have no special features to combat photorespiration.

3. So 3C plants are less drought tolerant


Why does this matter?

Although C3 plants are not as adapted to warm temperatures as C4 plants, photosynthesis of C3 plants is limited by carbon dioxide; and as one would expect research has shown that C3 plants have benefitted from increased carbon dioxide concentrations with increased growth and yields.

Increasing CO2 in air is making deserts greener

Another cut & paste:

"Focusing on the southwestern corner of North America, Australia’s outback, the Middle East, and some parts of Africa, Randall Donohue of the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra, Australia and his colleagues developed and applied a mathematical model to predict the extent of the carbon-dioxide (CO2) fertilization effect. They then tested this prediction by studying satellite imagery and teasing out the influence of carbon dioxide on greening from other factors such as precipitation, air temperature, the amount of light, and land-use changes.

The team’s model predicted that foliage would increase by some 5 to 10 percent given the 14 percent increase in atmospheric CO2 concentration during the study period. The satellite data agreed, showing an 11 percent increase in foliage after adjusting the data for precipitation, yielding “strong support for our hypothesis,” the team reports.
“Lots of papers have shown an average increase in vegetation across the globe, and there is a lot of speculation about what’s causing that,” said Donohue of CSIRO’s Land and Water research division, who is lead author of the new study. “Up until this point, they’ve linked the greening to fairly obvious climatic variables, such as a rise in temperature where it is normally cold or a rise in rainfall where it is normally dry. Lots of those papers speculated about the CO2 effect, but it has been very difficult to prove.”
He and his colleagues present their findings in an article that has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
The team looked for signs of CO2 fertilization in arid areas, Donohue said, because “satellites are very good at detecting changes in total leaf cover, and it is in warm, dry environments that the CO2 effect is expected to most influence leaf cover.” Leaf cover is the clue, he added, because “a leaf can extract more carbon from the air during photosynthesis, or lose less water to the air during photosynthesis, or both, due to elevated CO2.” That is the CO2 fertilization effect.
But leaf cover in warm, wet places like tropical rainforests is already about as extensive as it can get and is unlikely to increase with higher CO2 concentrations. In warm, dry places, on the other hand, leaf cover is less complete, so plants there will make more leaves if they have enough water to do so. “If elevated CO2 causes the water use of individual leaves to drop, plants will respond by increasing their total numbers of leaves, and this should be measurable from satellite,” Donohue explained.
To tease out the actual CO2 fertilization effect from other environmental factors in these regions, the researchers first averaged the greenness of each location across 3-year periods to account for changes in soil wetness and then grouped that greenness data from the different locations according to their amounts of precipitation. The team then identified the maximum amount of foliage each group could attain for a given precipitation, and tracked variations in maximum foliage over the course of 20 years. This allowed the scientists to remove the influence of precipitation and other climatic variations and recognize the long-term greening trend.
In addition to greening dry regions, the CO2 fertilization effect could switch the types of vegetation that dominate in those regions. “Trees are re-invading grass lands, and this could quite possibly be related to the CO2 effect,” Donohue said. “Long lived woody plants are deep rooted and are likely to benefit more than grasses from an increase in CO2.”
“The effect of higher carbon dioxide levels on plant function is an important process that needs greater consideration,” said Donohue. “Even if nothing else in the climate changes as global CO2 levels rise, we will still see significant environmental changes because of the CO2 fertilization effect.”
Via American Geophysical Union

So this is not just crackpot theory
  • More food
  • Lower food prices
  • Less acreage needed for farming
  • Greening of deserts
This is good climate change !
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#2
Meanwhile in Australia, more people die on the roads than in bush fires. Just not as newsworthy...

Three Men Die In 24 Hours As Victoria's 2020 Road Toll Gets Off To A Horror Start

Victoria’s road toll is off to a horror start in 2020.

2019 was a nightmare year for the state, with 288 people dying on our roads, up from a record low of 212 in 2018.

But this decade is proving even worse – 10 people have already lost their lives, up from seven at this point last year.

Three men died in a 24 hour period yesterday after fatal crashes in Rye and Pearcedale.

A second Victorian firefighter has died battling a blaze in the alpine region, bringing the state’s bushfire death toll to four and 27 nationally.

https://app.powerbi.com/view?r=eyJrIjoiM...Y1MTc4NCJ9
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#3
Here it's motorbikes. Maybe what? One vehicle in a hundred on the road is a two wheeler? Yet last year motorbikes accounted for the majority of deaths.

That is one scary stat for anyone considering buying a motorbike.

Wayne, I watched the news from NZ, USA and Aussie Sky. All had articles on the same topics - Aussie bushfires and global warming. You wouldn't think they were reporting from the same planet:

TVNZ News: Bushfires all caused by global warming and Adele penguins are dying out because of global warming. World has reached tipping point and we're all going to be drowned by sea level rise.

Aussie Sky News: Local politician and fireman committing to back burning in future to prevent rampaging bushfires. Arsonists charged. Warning about potential for flooding now the summer rainstorms have arrived.

Fox News: Massive new colony of Adele penguins found on the other side of Antarctic allaying fears their numbers were falling. Everything else about impeachment.

No wonder people turn off this stuff!
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