A Bigger contributor to GW than Carbon Dioxide.

[nemesis9]

Originally Posted by cbacba

Whether deforestation hurts or helps is not a simple question nor does it have a simple or obvious answer.

My hypothesis would be that deforestation hurts. Then, I would then try to estimate the forest area just prior to the industrial revolution and use that as a loose baseline. Now, that baseline wouldn't take into account the increase in population since then nor a few other changes either, but there would seem to be a way to use this baseline to restore forested area, and then try to reduce human CO2 emissions as much as practically possible.

[cbacba]

Originally Posted by nemesis9

My hypothesis would be that deforestation hurts. Then, I would then try to estimate the forest area just prior to the industrial revolution and use that as a loose baseline. Now, that baseline wouldn't take into account the increase in population since then nor a few other changes either, but there would seem to be a way to use this baseline to restore forested area, and then try to reduce human CO2 emissions as much as practically possible.

Well, most people play russian roullete with a revolver. There really aren't any repeat players that start out with an autoloader.

You're not even doing what you need to do to ascertain what the effects might be. Lets take the ultimate reforestation project of the sahara and assume that man is actually capable of reforesting it. First off, what is the albedo of that area? Sand is very high so far as surface area goes, much higher than forests of all types. Second, you need to find out what the albedo of your new forest would be. Third, you'll need to determine the water evaporation and content for the desert area and what the effects of installing a forest would be. This includes what the current cloud covering happens to be and estimates would have to be made concerning what the final expected cloud cover would be and fourth, what effect on albedo that the additional clouds happen to be. Fifth, you'd need to ascertain what effects of putting in a forest there would be on the dust content of the atmosphere and what effects that might have on warming or cooling and what effects that might have on the creation of tropical storms out past the canary islands - the ones that often turn into hurricanes. Sixth, you'll need to determine just what sort of demand increase there could be on plant life usage of co2. What if this stresses the system even with mankind's usage of co2 causing technologies? Finding out why the sahara's forests died out originally might be good and it might indicate they stressed out due to a lack of co2 concentration. It would also be good to be absolutely sure over the value of the solar constant back then before proceding as well. AFter all, we were just getting out of the little ice then so temperatures were naturally somewhat colder - hence the discoveries of lost mines, the abandoned colonization efforts of greenland by the vikings etc.

Depending on the outcome from these and numerous other anaylisis efforts needed, your hypothesis could very well be quite wrong and result in exacerbating the problem it is intended to solve. In fact, your very belief that we are indeed warming is actually very much in question. It would seem that may be answered by what the sun decides to do - such as have long feeble sunspot cycles as occurred during the LIA and Maunder minimum or short very strong cycles. Although quite premature, there is already some dicussion over in print of whether we may have a Maunder minimum headed our way starting sometime around the next two solar cycle time frames - assuming it hasn't started already.

[Besoeker]

Originally Posted by cbacba

if 80 ppm (or 100ppm) is responsible for 1.4 deg K rise from 1.5W/m^2, then each doubling would account for 3 deg K rise in temperature. Since the earth's atmosphere is responsible for a 33K rise in T over no atmosphere, then the 12 doublings which have occurred for co2

CO2 has increased by a factor of 4000?

[Bored Wombat]

Originally Posted by cbacba

Finding out why the sahara's forests died out originally might be good and it might indicate they stressed out due to a lack of co2 concentration.

The collapse of the Sahara forests occurred at a time when atmospheric CO2 was at the high point in its natural cycle, not a low point.

Until the recent increase due to the combustion of fossil fuels, Atmospheric CO2 concentrations have cycled between essentially the same levels for at least a million years, being about from 180ppm to 280ppm.



Analysis of plant pollens and bones have shown that the collapse of the Sahara to desert only occurred about 5000-6000 years ago. The ice age had ended, and the warmest part of the ice age cycle had arrived already. CO2 concentrations were over 250ppm, significantly above the 200ppm that existed 10,000 years before that.



Forests don't tent to die from lack of CO2, especially rainforests, which house a large proportion of the world's biodiversity. Quite the opposite.

This paper published in October last year shows that overall during warm "greenhouse" periods, biodiversity is lower, while extinction rates and species origination rates are higher than in cool periods.

[Bored Wombat]

Originally Posted by cbacba

In fact, your very belief that we are indeed warming is actually very much in question.

In blogs funded but fossil fuel interests or Bush foreign policy supporters, but not in science or scientific literature.

[Windguy]

Originally Posted by nemesis9

My hypothesis would be that deforestation hurts. Then, I would then try to estimate the forest area just prior to the industrial revolution and use that as a loose baseline. Now, that baseline wouldn't take into account the increase in population since then nor a few other changes either, but there would seem to be a way to use this baseline to restore forested area, and then try to reduce human CO2 emissions as much as practically possible.

I am trying to see because of the current drought crisis Australia has endured that evaporation slow down has occured. There isn't enough data, and the data there is doesn't help prove anything.

Another possible problem is to define it through all of these.

Australian Climate Influences

One thing that was said to me from a 39 yr experienced meteorologist is the sub tropic areas of the planet are usually deserts. which goes right across the guts of Australia and around other places such as the red sea.

[Windguy]

Trend Maps

Forest evaporation is separate (not wholly independant), so this just covers pan evaporation.

Shows proof of the evaporation process is slowing down. So that is occuring all over Australia except the sub tropic area which is usually hot and dry, and is a desert. So that sub tropic region is the only region where evaporation is speeding up and that is because through climate change it is becoming hotter and drier still.

We have to assume Australia is still losing forests (which it is and has accelerated by 70% within the last few years). So you can connect the dots, but you can't eliminate any other theories if there is any. Warming oceans alone can create similar circumstances, and the ocean can just heat up from the greenhouse effect alone.

[forfismum]

Originally Posted by Windguy

We have to assume Australia is still losing forests (which it is and has accelerated by 70% within the last few years).

Haven't seen many papers on Oz forests,any good linkies Windy?It would be interesting to get a handle on the historic aspects.My impression of Oz is one of a dry continent since the year dot,with wisps of forest around the coasts.
regarding the Sahara,that has been there since biblical times,the Sahel is the current problem but just think,no Sahara no Amazon.Or indeed no growth in parts of the uSA and Southern Europe.

[Windguy]

The last article I read in the newspaper. But here is one link to a deforestation study.

Underlying Causes of Deforestation: Australia

And one study about deforestation lowering rainfall.

Tropical Deforestation Affects Rainfall Around the Globe | Climate Change Australia

[Windguy]

We normally have about 20% of Australia being forests, so 1/5 is still a fairly large number for a country classed as arid.