module 5-green house gasses & climate change Flashcards
what are greenhouse gasses
natural and manmade atmospheric gases that trap heat
what is the greenhouse gas effect
it occurs when some of the solar energy that reaches the earth’s surface is radiated back to the atmosphere as heat where it is absorbed by the greenhouse gases
how do greenhouse gasses work
they absorb the heat let off from the earth and create a blanket of warmth around the earth by preventing all of the heat from escaping beyond the atmosphere
how much atmospheric gasses do GHG account for (excluding water vapor)
less than one percent
are GHGs always bad
no, they are essential for life
what would happen if there was no such thing as GHGS
the temp on earth would vary, like the temperatures on the moon, from 134C when the surface is facing the sun and -153C when the surface of the moon is away from the sun
how much water vapor is on earth
it can range from 0-4% depending on location, season, and time of day
what characteristic does water vapor have that other GHGs don’t have
water vapor is a condensable gas and the amount of water vapor in the air increases as temperature increases
what causes global warming
an increase in the amount of GHGs
what is the major naturally occurring GHGs
CO2, CH4, N2O, and H2O
what GHGs are naturally cycled in the earth’s biosphere through the soil-plant-animal process
methane, nitrous oxide, and carbon dioxide
what is the global warming potential of CH4
about 25x that of CO2
what is the global warming potential of N2O
about 298x the potential of CH4
how does the amount and power of N2O and CH4 compare to CO2
nitrous oxide and methane have much more potential energy absorbers but there is much less N2O and CH4 than CO2. but they will have a much higher proportional effect on global warming
how is the greenhouse gas potentials expresses
in terms of CO2 equivalents. which is calculated by multiplying the metric tonnes of the gas released by its global warming potental
at what point was there a dramatic increase in GHGs
data over the last 2000 years have demonstrated a huge increase in GHGs have occurred since the industrial revolution
in the last two decades how much has CO2 increased.
by 30 parts per million prior to that it never increased that much over a 1000 year period
post-industrial revolution how were all the GHGs believed to be caused
human-caused as a result of burning fossil fuels for energy
how much has the temperature of the earth increased since the 1800s
the mean temperature of the earth’s surface has risen 0.6oC
what is the predicted temperature increase supposed to be for the year 2100
it ranges from 1.4C to 5.8C
what does global climate change refer to
refers to the increasing changes in measures of climate over a long period of time and global warming is one aspect of global climate change
what word more accurately defines the effects of the accumulation of greenhouse gases in the atmosphere
global climate change
what other alterations come with global climate change
changes in precipitation patterns causing increases in drought areas as well as flooding, changes in wind patterns, more frequent and severe storms, and hurricanes, increase sea levels as polar ice melts and coastal lands will be lost.
how will affect agriculture be affected by global climate change
Changes in growing seasons and alterations in the plants that can survive in different areas of the world will occur as a consequence of climate change; this will benefit some areas of the world and be devastating to others.
how does the natural carbon cycle work
carbon cycle involving plants, animals and the soil releases CO2 and CH4 into the atmosphere and removes them from the atmosphere; anthropogenic activities increase the amount of CO2 and CH4 released into the atmosphere to a level above that which can be taken up by plants and the soil
what do plants do to atmospheric CO2
they convert it into biomass. from there carbon accumulates in the soil as part of the organic soil content
what happens to carbon released from the soil
Carbon from the soil is released to the atmosphere as CO2 or CH4 through soil respiration and microbial degradation
what happens to carbon that is taken up through animals eating plants
Animals consuming plants take up carbon which is released to the atmosphere as CO2 through respiration or processed by microbial fermentation and released as CO2 or CH4. Some of the carbon is also returned to the soil through excreta or the breakdown of bodies, contributing to the organic matter (OM) of the soil
how do human activities affect the carbon cycle
they disrupt the balance of the carbon cycle by producing emissions over and above what can be taken up by plants as well as by reducing carbon storage
explain the balance of carbon between the atmosphere the soil and biotic components of the earth conditions
it requires equivalency between carbon release and uptake. The amount of carbon taken up from the atmosphere and released into the atmosphere from various sources.
what does the imbalance of the carbon cycle do caused by the burning of fosses fuels and deforestation? how can we offset this increase
they create an imbalance in the carbon cycle resulting in a net increase in atmospheric carbon. To offset this increase, we will need to find ways of reducing carbon emissions into the atmosphere and/or taking CO2 and CH4 out of the atmosphere.
currently how much carbon are we putting into the earth, taking out, and what is the net difference
we are putting 117-119 billion tons into the earth, 112.5 is being taken out, there is a net difference of 4.5 to 6.5 billion tons
what is the biggest outputs of carbon into the atmosphere
1) soil organic matter oxidation and erosion
2) respiration from living organisms
3) burning fossil fuels
4) deforestation
what are the biggest contributors to the ti=hings taking carbon out of the atmosphere
1) photosynthesis
2) defusion into the ocean
how does the nitrogen cycle work
involves the removal of nitrogen from the atmosphere into the soil by nitrogen fixation carried out by soil and root bacteria
what happens to fixed nitrogen
The fixed nitrogen is converted into a form that can be utilized by plants through processes of ammonification and nitrification
how can other bacteria release fixed Nitrogen
Other bacteria release fixed nitrogen as N2O through denitrification
what can increase denitrification
Soil disturbance can result in an increase in denitrification and N2O release into the atmosphere. Over-application of manure and man-made fertilizers containing nitrogen increases the amount of N2O released into the atmosphere and contributes to soil nitrogen. Denitrification also occurs in manure, releasing N2O into the atmosphere.
