Quote:
Originally Posted by archineer
Co2 is a greenhouse gas- we've increased co2 concentrations by roughly 35% through industrialisation. Two indisputable facts, its not exactly rocket science.
Hands up who has a degree in climatology?
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guess what
co2 levels were over 700 ppm 20 thousand years ago....so what's the big deal
guess what, by science no less...the ideal co2 ppm for hemp is....700 ppm
As the air's CO2 content rises, most plants exhibit increased rates of net photosynthesis and biomass production. Moreover, on a per-unit-leaf-area basis, plants exposed to elevated CO2 concentrations are likely to lose less water via transpiration, as they tend to display lower stomatal conductances. Hence, the amount of carbon gained per unit of water lost per unit leaf area - or water-use efficiency - should increase dramatically as the air's CO2 content rises. In the study of Serraj et al. (1999), soybeans grown at 700 ppm CO2 displayed 10 to 25% reductions in total water loss while simultaneously exhibiting increases in dry weight of as much as 33%. Thus, elevated CO2 significantly increased the water-use efficiencies of the studied plants.
In summary, it is clear that as the CO2 content of the air continues to rise, nearly all of earth's agricultural species will respond favorably by exhibiting increases in water-use efficiency. It is thus likely that food and fiber production will increase on a worldwide basis, even in areas where productivity is severely restricted due to limited availability of soil moisture. Therefore, one can expect global agricultural productivity to rise in tandem with future increases in the atmosphere's CO2 concentration.
so more co2 is actually GREENER
its not theroy, its scientific fact
science shows that humans use oxygen and expele (exhale) co2
science shows that greenery (plantlife) uses co2 and expeles o2
science shows that co2 levels have been 3 times HIGHER than they are today, in the past (ie the co2 325 of today is is much lower than the 750-800 that co2 levels were 100,000 years ago
science shows us that the earth has warmed AND cooled many times
science shows us that ANTARTICA was once a lush furtile land, not covered in ice
science shows us that greenland was once a green lush furtile land, not covered with ice
science shows us that GLACIERS created many of the geographical features that we look at today (ie Long Island was made by the lower reaching of graciers, the great lakes were created by glaciers, the grand canyon was created by glacial melting)
science shows us that plants would grow much better, and use less water if the co2 was HIGHER
common sense states that as the earths polulation expands, so does the need for more plantlife...to keep our oxygen levels up.......yet the global warming people only want to talk about car/industry exaust; man created co2,.... and how to tax it
there are plenty of other benefits to the planet from global warming. Because warming is concentrated at the poles, large sections of the continental landmasses in the Northern Hemisphere that are currently too cold to be used for productive agriculture would become usable. Current agricultural lands would be warmed, but not as seriously impacted as warming closer to the equator is less severe. Also, warming is supposedly more prevalent during the winter months, lessening the length and severity of cold months leading to longer growing and allowing us to spend less of our resources on heating (wood, fossil fuels, electricity). Furthermore, warming would increase air temperature near and water temperature in the oceans, leading to increased evaporation and moisture in the atmosphere. This moisture would then fall as rain on the continents, further increasing the land's agricultural carrying capacity, thus allowing us to grow more food (and lessen the severity of current water shortages).
so more co2 is actually GREENER
The most recent glaciation began about 125,000 years ago and climaxed about 21,000 years ago. At this time, over 30% of the earth’s surface was covered by ice, and sea level was at least 125 meters lower than present
here is some history for you
The historical record tells us of many warming episodes - and subsequent cooling periods - that have bedevilled humans for thousands of years.
The ancient Greek philosopher Plato, who lived in 427-347 BC, wrote about major climate changes known in his day. In the dialogue, "Timaeus," he argued global warming occurs at regular intervals, often leading to great floods. Said Plato, "When... the gods purge the Earth with a deluge of water, the survivors... are herdsmen and shepherds who dwell on the mountains. But those who... live in cities are carried by the rivers into the sea."
In the dialogue, "Critias," Plato wrote about weather-related geological changes. He referred to "formidable deluges" that washed away all the top soil, turning the land into a "skeleton of a body wasted by disease." What were now plains had once been covered with rich soil, Plato said, and barren mountains were once covered with trees. The yearly "water from Zeus" had been lost, he went on, creating deserts where the land was once productive.
Plato's student, Aristotle, who lived from 384 BC to 322 BC, also recorded evidence of global warming in his work, "Meteorologica." He noted that in the time of the Trojan War, the land of Argos was marshy and unarable, while that of Mycenae was temperate and fertile. "But now the opposite is the case," Aristotle wrote. "The land of Mycenae has become completely dry and barren, while the Argive land that was formerly barren, owing to the water has now become fruitful." He observed the same phenomenon elsewhere covering large regions and nations.
Theophrastus, a student of Aristotle who lived 374-287 BC, discussed climate change in his work, "De ventis," which means "The Wind." He observed that in Crete, "nowadays the winters are more severe and more snow falls." In earlier times, he said, the mountains there bore grain and fruit, and the island was more populous. But when the climate changed, the land became infertile. In his book, "De causis plantarum," Theophrastus noted the Greek city of Larissa once had plentiful olive trees but that falling temperatures killed them all.
In the first century AD, an ancient Roman named Columella wrote an agricultural treatise called, "De re rustica." In it, he discussed global warming that had turned areas once too cold for agriculture into thriving farm communities. Columella cites an authority named Saserna who recorded many such cases. According to Saserna, "regions which formerly, because of the unremitting severity of winter, could not safeguard any shoot of the vine or the olive planted in them, now that the earlier coldness has abated and weather is becoming more clement, produce olive harvests and the vintages of Bacchus [wine] in greatest abundance."
In the Middle Ages, people began recording the temperature and climate-related phenomena, such as the dates when plants began to blossom annually. They were aware of a warming trend that began around 900 and a cooling trend that began around 1300. We know that during the warm period, the Vikings established settlements in Greenland where perpetual ice had previously covered the land. Ancient Norse records tell us these settlements were abandoned after 1250 when falling temperatures made farming less viable and spreading ice in the sea made transportation more difficult.
The cooling trend led to heavy rains in 14th century Europe that were too much for the crops, leading to reduced agricultural output and numerous famines. In the 15th century, a warming trend returned, which lasted until the middle of the 16th century when temperatures again started to fall. By the 17th century, it was clearly apparent that a cooling trend was altering sea routes, changing the kinds of crops farmers could grow, fishing patterns and so on. Glaciers began to advance rapidly in many places and rivers that had long been ice-free year round started to freeze in the winter. This "little ice age" continued well into the 19th century.
Since then, we have been in a warming cycle that appears to have accelerated around 1950. The point is that we know a great deal about climate changes from the historical record and need not rely solely on scientific studies of core samples, tree rings and so on. These changes occurred long before industrialization and could not possibly have been man-made in any way. They don't prove man is not now affecting the climate through carbon dioxide emissions, but they do tell us temporary warming trends are common in human history. It may only be a matter of time before another cooling trend comes along.
you see the problem,,we are not saying that there is no such thing as global warming/cooling...we are saying that it is a NATURAL OCCURANCE.....The simple FACT is, to say its 'man-made' is just a LIE...do we humans help/hinder it...certainly..but we are not the CAUSE
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