How does biosphere affect the atmosphere

As ice sheets in the hydrosphere melt, polar bear reproduction in the Arctic decreases. As the atmosphere temperature rises in northern latitudes, Spruce Pine Beetles are migrating north and killing massive amounts of coniferous trees.

Biosphere's Impact on Other Spheres. When organic plant matter dies and decomposes, such as in a peat bog, methane and CO2 are released into the atmosphere, increasing the amount of greenhouse gasses. The biosphere also releases more methane into the atmosphere through the digestive system of cattle containing methane releasing bacteria.

This flux in methane in the atmosphere increases the amount of greenhouse gasses and leads to global warming. National Academy of Sciences arranged a study of possible climate change, the panel mainly considered urban and industrial influences, that is, deliberate human excavation and emission of materials.

The experts remarked that changes involving living creatures in the countryside, such as irrigation and deforestation, were "quite small and localized," and set that topic aside without study.

Yet as the panel realized, the planetary environment was certainly affected by human activity. During the s, evidence mounted that such human products as nuclear bombs and chemical pesticides could inflict global harm. The comfortable traditional belief in the automatic stability of biological systems was faltering. These feelings connected with concern for the entire atmosphere when C.

Keeling published his data on changes in the level of CO 2. His measurements were so precise that from the outset, they showed a seasonal "breathing" of the planet: plants in the northern hemisphere took up carbon from the atmosphere in spring and summer, and returned it to the air when dead leaves and grass rotted away in autumn and winter.

One could even use Keeling's data to figure how many tons of carbon cycled through the plants each season. Keeling's curve was just one of many things that raised concern about global biological effects. In the early s, public sensitivity redoubled following a series of climate disasters, especially a drought in the African Sahel. Photographs of starving children, huddled in a barren landscape of scrub, told a terrible story of expanding deserts and changing climates.

Was the Sahara desert expanding southward as part of a natural climate cycle that would soon reverse itself, or was something more dangerous at work?

For a century, African travelers and geographers had worried that overgrazing could cause changes in the land that would turn the Sahel into a "man-made desert. The Sahara was not so much encroaching, one scientist remarked in , as taking advantage of "man's stupidity. Noting that satellite pictures showed a widespread destruction of vegetation in the Sahel from overgrazing, he pointed out that the barren clay reflected sunlight more than the grasses had.

He figured this increase of albedo surface reflectivity would make the surface cooler, and that could change the pattern of winds so as to bring less rain. Then more plants would die, and a self-sustaining feedback would push on to full desertification. Charney was indulging in speculation, for computer models of the time were too crude to show what a regional change of albedo would actually do to the winds. It would be a few more years before models and observations demonstrated what had long been suspected — surface vegetation is an important factor in the climate.

For example, the Amazon rain forest generates much of its own rainfall through evaporation. It would take a still later generation of models to show that Charney's specific mechanism was valid to a degree.

It was an influence, but not the only one, in a complex set of interactions involving other factors, such as variations in the surface temperature of the Atlantic and Indian Oceans. In the Sahel, the advance of the desert halted and in the s went into reverse, showing that overgrazing did not by itself dominate changes. But the question of human influence remained open. Later studies suggested that along with overgrazing, human emissions, not only of greenhouse gases but also of industrial haze, had caused changes in weather patterns that contributed to the disaster.

Human activity could change vegetation enough to affect albedo, and a change in albedo could interact with other factors to change climate. More generally, the biosphere did not necessarily regulate the atmosphere smoothly through "negative" feedbacks that pulled the system back from any change. It could itself be a source of the kind of "positive" feedbacks that amplified changes.

Where Does the Carbon Go? The science of biology was in no condition to answer the questions that climate scientists were starting to bring. To meet that demand, most biologists concentrated their research projects on one or another particular species if not a single molecule.

Even the pioneering scientists who had begun to consider larger systems rarely undertook field studies that lasted as long as five years. That was hardly enough to see how a biological community might respond to climate change. Nevertheless the study of living communities in all their complexity was gradually growing in scale and sophistication, under the newly popular banner of ecology. The field was attracting researchers who were curious about human impacts on the environment.

By the early s, everyone had grown sensitive to a variety of ways that humans were affecting the planet as a whole. The public was becoming aware, in particular, that slash-and-burn farming was eating its way through entire tropical forests. People realized that only a small and diminishing remnant remained of the great ancient forests of North America, and the same fate threatened the rest of the planet's trees. Concern about the destruction of forests was on the rise, although the concern was for the sake of wildlife, not climate.

Meanwhile a few scientists pointed out that the world's forests were a significant player in global cycles of carbon and water. The conversion of forests to croplands since the early 19th century had given the first big contribution to the global rise of CO 2. Decades later, scientists realized that deforestation also contributed to cooling — for one thing, snow on exposed soil reflects more winter sunlight than a forest does — so the net effect of deforestation may have helped keep the 19th century cool.

Moreover, as anyone who has walked sweating through a steamy jungle might understand, a forest evaporating moisture can be wetter than an ocean, in the way it affects the air overhead.

The ancient ideas about climate change from deforestation looked plausible again. Only now it was not just local weather, but the entire global climate that could be affected. Just what kind of changes would further deforestation bring? As one scientist who pioneered study of the subject remarked, "it is difficult even to guess.

There were a few things that could be measured with confidence. Statistics compiled by governments on the use of fossil fuels told how much CO 2 was going into the atmosphere from industrial production.

And Keeling's measurements showed how much of that remained in the air, to push the curve higher year by year. The two numbers were not equal. Roughly half of the gas from burning fossil fuels was missing. Where was the missing carbon going? There were only two likely suspects. It must wind up either in the oceans or in biomass. In , the geochemist Wallace Broecker and colleagues developed a model for the movements of carbon in the oceans, including the carbon processed by living creatures.

While admitting that knowledge of biological interactions was inadequate, they thought it likely that the "biosphere is not an important sink" for swallowing up CO 2. The residue must somehow be sinking into the biosphere. Perhaps trees and other plants were growing more lushly thanks to CO 2 fertilization?

If so, that was hard to check. The pioneering carbon box models mostly concentrated on chemistry and did not attempt to calculate whether any organisms might grow more abundantly when CO 2 and warmth increased.

Some ocean carbon calculations entirely left out not only plants but all the terrestrial biota, that is, all organisms on land. Plant biologists — a type of specialist that had scarcely interacted with climate scientists — had published few solid studies of carbon fertilization.

It was clear enough in greenhouses, but that said little about what would happen amid the complexities of a real forest. The prevailing view had been established in the s by Eugene Odum, the pioneering author of the dominant ecology textbook. In a mature ecosystem, Odum maintained, gains and losses of carbon precisely balanced one another. What was clear in , as Keeling pointed out, was that even with good data on past and present conditions, any calculation of the future fertilizer effect would be unreliable.

Every gardener knows that giving a plant more fertilizer will promote growth only up to a certain level. Nobody knew where that level was if you gave more CO 2 to the world's various kinds of plants. As Hutchinson had suggested back in , deforestation and other human works would increase decay in soils, so the land biota could be a major net source of the gas. The respected meteorologist Bert Bolin broke with his earlier view that plants were not a major source of CO 2.

He argued that deforestation of the tropics, plus the decay of plant matter in soils damaged by agriculture, was releasing a very large net amount of CO 2 into the atmosphere — somewhere around a quarter of the amount added by fossil fuels. Since the level in the atmosphere was not rising all that fast, it followed that the oceans must be taking up the gas much more effectively than anyone had thought.

Bolin admitted that "This result is difficult to reconcile with present models of the role of the oceans. George Woodwell, a botanist who had recently joined the Marine Biology Laboratory at Woods Hole to direct their Ecosystems Center, went still further with calculations he had begun independently of Bolin.

Woodwell believed that deforestation and agriculture were putting into the air as much CO 2 as the total from burning fossil fuel, or maybe even twice as much. His message was that the attack on forests must be stopped, not just for the sake of preserving nature but also to avoid disrupting the climate.

Broecker and other geochemists thought Woodwell was making ridiculous extrapolations from scanty data. Defending their own calculations, the geochemists insisted that the oceans could not possibly be taking up so much carbon. People's beliefs about the sources of CO 2 were becoming connected to their beliefs about what actions if any governments should take.

Researchers tried to resolve the problem scientifically, attacking it from many directions. In meetings, workshops, and publications the experts met and wrangled, sometimes bitterly but always politely.

As occasionally happens in scientific debates, opinions divided largely along disciplinary lines: oceanographers plus geochemists versus biologists. The physical scientists like Broecker pointed out that they could reliably calibrate their models of the oceans with data on how the waters took up radioactive materials fallout from nuclear weapon tests was especially useful.

Woodwell's biology was manifestly trickier. His opponents argued that nobody really knew what was happening to the plants of the Amazon and Siberia. When he invoked field studies carried out in this or that patch of trees, his opponents brought up more ambiguous studies, or just said that studies of a few hectares here and there could scarcely be extrapolated to all the world's forests. Key data came from measurements of carbon in old wood. This used the fact that new radioactive isotopes cycled through the atmosphere and plants, whereas fossil fuel emissions had long since lost any radioactivity.

In , Minze Stuiver used isotope measurements to estimate that two-thirds of the CO 2 added to the atmosphere up to had come from cutting down forests. But global industry and population had been multiplying explosively.

The situation had changed, and now nearly all the new carbon was coming from fossil fuels. The ocean models were roughly correct. This did not mean that forests were unimportant. The way Keeling's CO 2 curve swung up and down with the seasons showed plainly that the springtime growth and autumn decay of plant matter played a huge role in the atmosphere's carbon budget.

But averaged over a year, the gas emitted from decaying or burned plants seemed to be roughly balanced by the amount taken up by other plants. Maybe deforestation was balanced by more vigorous growth due to fertilization by the increased CO 2 in the atmosphere — "a chance compensation of opposed effects. Woodwell denied this, and through the s, he continued to insist that tropical deforestation and other assaults on the biosphere were contributing about as much net carbon to the air as the burning of fossil fuels.

Calling carbon dioxide "a major threat to the present world order," he called not only for a halt to burning forests but for aggressive reforestation to soak up excess carbon.

Saving the forests, more for the sake of wildlife than of climate, was a popular idea in the growing environmental movement — a movement in which Woodwell had long been a leader. Eventually Woodwell had to concede that deforestation was not adding as much CO 2 to the atmosphere as he had thought. An important lesson remained. As a team headed by Broecker wrote in , Woodwell's claims that destruction of plants released huge amounts of CO 2 had been a "shock to those of us engaged in global carbon budgeting.

The only areas so poorly understood that they might hide such a huge feature of the system were biological. Taking his own advice, Broecker began to look at seawater as a container not only of chemicals but of life.

In a pair of seminal papers he drew attention , he drew attention to what was later called a biological carbon "pump. After they die, fragments eventually snow down to the ocean floor, where the carbon is buried in sediments. One might suppose that adding more plankton would immediately reduce the amount of CO 2 in the atmosphere.

Further investigation, however, showed that the short-term effect is not straightforward. When creatures make calcium carbonate for their shells, they alter the complex chemistry of seawater, which actually ends up releasing more of the gas into the air. Scientists had much to study in the many biochemical changes that occur as plankton flourish and dissolve. In studying all this, Broecker and his colleagues were not concentrating on what it meant for the contemporary carbon budget.

Their chief interest was what the burial of carbon over thousands of years might mean for the swings between ice ages and warm periods. Over the long run, the more carbon was buried, the less there should be in the atmosphere. May 26, GHG's primarily. Explanation: I'll break down the question: combustion refers to burning, which, as a base reaction releases CO2 and H20, but in reality, combustion reactions release much more.

What are the global wind belts? Why is carbon dioxide in the atmosphere increasing? The biosphere benefits from this food web. The remains of dead plants and animals release nutrient s into the soil and ocean. These nutrients are re- absorb ed by growing plants. This exchange of food and energy makes the biosphere a self-supporting and self-regulating system. The biosphere is sometimes thought of as one large ecosystem —a complex community of living and nonliving things function ing as a single unit.

More often, however, the biosphere is described as having many ecosystems. Biosphere Reserves People play an important part in maintaining the flow of energy in the biosphere. Sometimes, however, people disrupt the flow. For example, in the atmosphere, oxygen levels decrease and carbon dioxide levels increase when people clear forest s or burn fossil fuel s such as coal and oil.

Oil spill s and industrial wastes threaten life in the hydrosphere. The future of the biosphere will depend on how people interact with other living things within the zone of life. A network of biosphere reserves exists to establish a working, balanced relationship between people and the natural world. Currently, there are biosphere reserve s all over the world. The first biosphere reserve was established in Yangambi, Democratic Republic of Congo. Yangambi, in the fertile Congo River Basin, has 32, species of trees and such endemic species as forest elephants and red river hogs.

The biosphere reserve at Yangambi supports activities such as sustainable agriculture , hunting, and mining. One of the newest biosphere reserves is in Yayu, Ethiopia. The area is developed for agriculture. Crop s such as honey, timber, and fruit are regularly cultivate d. This shrub is the source of coffee. Yayu has the largest source of wild Coffea arabica in the world.

Biosphere 2 In , a team of eight scientists moved into a huge, self-contained research facility called Biosphere 2 in Oracle, Arizona. Inside an enormous, greenhouse-like structure, Biosphere 2 created five distinct biomes and a working agricultural facility.

Scientists planned to live in Biosphere 2 with little contact with the outside world. The experiments carried out in Biosphere 2 were designed to study the relationship between living things and their environmentand to see whether humans might be able to live in space one day. The mission was supposed to last years, with two teams of scientists spending 50 years each in the facility.