CC bio baylor
1. There is a simpler method of downscaling than either dynamic or statistical downscaling. What is it called?
"Difference Method. " Involves Smoothing and interpolation. In this process, present climate data are interpolated to a desired scale, such as 1 km. The difference between present and future GCM simulations is then added to the interpolated current climate data yielding a future climate surface at the desired scale.
1. What kinds of conditions can drive range shifts in species?
Abundance, which is often governed to some degree by climate determines whether populations endure. Long term changes in mean climate state, climatic extremes such as freezing, or by interactions with other species being driven by climate change
1. What are the advantages and disadvantages of using only one GCM, several GCMs, or a large number of GCMs to assess climate change impacts?
Accessing possible outcomes against a variety of GCM projections can help capture uncertainty about possible futures. For instance, for many regions, projected change in rainfall varies from an increase in some GCMs to a decrease in others. Using several projections can help bracket these possible outcomes. In some circumstances, taking ensemble combinations of GCM projections can be more accurate than using them separately to bracket possibilities.
1. What are some examples of teleconnections?
An example of a teleconnection coupled change is the complement to el nino conditions being la nina events in which upwelling in the pacific is enhanced and rainfall is reduced.
1. One of the inputs into GCMs is how much CO2 human activities will (in the future) emit into the atmosphere. How is this information obtained?
Assumptions are made in every GCM about how much CO2 is released into the atmosphere over the time period being modeled. The IPCC tracks it and shows how much CO2 is equivalent to each RPC.
1. At the beginning of this section on modeling (p. 41), the author states that the typical horizontal resolution of a GCM is 100-200 km. Why is this level of spatial resolution, and not a finer spatial resolution such as 15-20 km, used for GCMs?
Because they are supposed to represent a larger area of space compared to models (RCMs) that focus on a smaller area. This is why combining both models gives the most in depth and fine examination of an area. They are meant to be large because they are on a global scale.
1. Why is the movement of water so important in Earth's climate system as a factor that affects climate warming?
Because water vapor has powerful heating and cooling effects, the movement of water is of unparalleled importance in the climate system. Water moves through hydrologic cycle, evaporating from the oceans, condensing as clouds, and then raining out over land to form fresh water that flows to the sea. Increases in global temperature can accelerate this hydrologic cycle by speeding up evaporation from the ocean surface.
1. How do we know that CO2 in the atmosphere has risen sharply during the last 50 years? Are our measurements of this CO2 influenced by local air pollution?
Because we have been recording the rise in CO2 due to fossil fuel burning and deforestation and have been tracking it at Mauna Loa which was chosen because it is an island location and high elevation place it far away from short term contamination from any city air pollution. So no it is not influence by local air pollution.
1. Why do most assessments of climate change use simulations from more than one GCM?
Because, no model simulates the future perfectly. Using more than one GCM therefore, helps researchers explore the uncertainty in possible future climates.
1. Explain what El Niño events are.
Best known of multiple state patterns. Ocean circulation patterns change across the pacific ocean. Rain patterns shift and atmospheric circulation changes in response to alterations in ocean water temperatures. These effect are felt in the pacific but are also reflected in other far distant parts of the globe. El nino years are associated with less upwelling of deep ocean water and enhanced rainfall in the pacific but also with decreases in rainfall and drought in Africa. Causing long distance effects.
1. Which is more relevant to biology, global mean temperature or regional temperature? Explain.
Biological impacts happen in specific places that all have their own unique climate characteristic important to species survival - the global mean fuzzes all these meaningful regional variations into one number. For instance, the variation between islands. Therefore they use regional temperatures.
1. What is the chemical effect on oceans and some of its inhabitants of higher [CO2] in the atmosphere?
CO2 dissolves on seawater to produce acid and reduce the amount of calcium carbonate held in the water. Reduced saturation state makes it more difficult or impossible for creatures to secrete calcium carbonate shells or skeletons. Consequences may include extinction, reduced abundance, or range shifts for species as diverse as squid, shelled sea creatures and corals. Acidification can have direct effects by altering the pH of seawater.
1. In what sense could climate change affect a species' niche, as defined by Hutchinson?
Climactic gradient shifts have come as a result of global warming. Species' climatic tolerance do not change, so they must track suitable climate to survive. If climate changes outside of the gradient, then species would have to move to a space where that gradient was present.
1. What is niche tracking?
Climate changes drive populations and species to track suitable climate conditions rather than going extinct. Occupying new areas and leaving unsuitable locations as climate changes is niche tracking
1. What is a major determinant of niche space for an organism?
Climate plays a major role in defining the niche of all species. Temperature, moisture, etc. suitable climatic conditions.
1. In what ways do biological systems and climate interact?
Climatology is relevant to climate change biology but most climate studies fall outside the discipline. However, when climatologists conduct studies specifically to unlock biological mysteries, climatology is part of climate change biology. The climate system in many respects is driven by biology. Biological by-products are the very gases that capture the warmth of the sun and transform the planet. Everything from the color of plants to the cycling f moisture between plants and the atmosphere.
1. What is dynamic downscaling?
Dynamic downscaling nests a fine scale climate model or RCM within a GCM.
1. How did the ozone layer enable terrestrial life on Earth to develop?
Early photosynthesis lead to making oxygen a major component of the atmosphere. Much of tis photosynthesis occurred in microbial mats, some of which formed structures known as stromatolites. By 600 M years ago, oxygen buildup was sufficient to support the formation of an ozone layer in the upper atmosphere. Sunlight hitting the upper atmosphere split O2 atoms to create free oxygen radical , some of which recombined with oxygen to form ozone. The ozone layer allowed terrestrial life to emerge previously life had been possible only in oceans where the water column shielded organisms from damaging UV radiation. With the emergence of the ozone layer, UV radiation was screened out in the upper atmosphere, allowing life forms to emerge onto land.
Eccentricity
Eccentricity: Shape of Earth's orbit -> nearly circular to strongly elliptical variations.
1. Explain the three main types of Earth orbital variation affecting the Earth's climate.
Eccentricity: Shape of Earth's orbit -> nearly circular to strongly elliptical variations. Obliquity: Amount of tilt Earth has on its axis Precession: Direction of tilt of Northern hemisphere toward the sun These effect heat during seasons greater than solar overall energy reaching Earth.
1. What has caused more and more coral bleaching in recent years?
El Nino has caused warming of oceans as well as human induced warming of the oceans.
1. If you wanted to examine a regional ocean phenomenon in high detail, how could you do so without exceeding the computational capabilities of your hardware?
Embed an RCM into a GCM.
1. What factors have contributed to this rise in atmospheric CO2?
Factors that have contributed to this rise in atmospheric CO2 is, burning of fossil fuels, and deforestation.
1. Provide examples of how the higher resolution of a RCM (~10-80 km) is appropriate for many regional impact assessment applications.
For example the features like the North American western mountains are represented by more detail rather than a hump that completely down plays the important points in the sierra Nevada and rocky mountains found in Northern America. Also orographic rainfall, temperature variation with altitude etc.
1. Why does the burning of fossil fuels lead to a higher [CO2] in the atmosphere?
Fossil fuels are rich in carbon, and burning them both releases their stored energy and combines their carbon with oxygen to produce CO2 in excess which leads to a higher CO2 level in the atmosphere.
1. How are GCMs used to establish the role of human-induced emissions in climate change?
GCM simulations are run for the recent past using only natural drivers of climate change and compared to observed warming trends. In general, GCMs are able to reproduce the full range of warming that has been observed since the last decades of the twentieth century only when human drivers of change are included in the models. This is generally taken as strong evidence that human pollution is the cause of recently observed climate change.
1. Explain the basic structure of general circulation models (GCMs).
GCM's use a system of mathematical equations to simulate the movement of mass and energy from one part of the atmosphere to another. They divide the atmosphere and ocean into a series of three-dimensional cells, each of which transfers mass and energy to its neighbors based on the outcome of the equations within the cell. These are in principle the same type of model used to predict weather, but they are run on a broader (global) scale and for centuries rather than days.
1. Over what spatial area do GCMs simulate climate change?
GCM;s simulate climate changes across the entire planet. These models are more often referred to as GCMs because they simulate general atmospheric circulation patterns.
1. GCM output data that are saved are usually not daily observations but rather monthly means of rainfall, temperature, and wind speeds. Are monthly means useful in biological studies?
GCMs do not always save the data most relevant to biological analysis. Organisms may respond to extreme events, such as droughts or severe storms, that are not captured in mean monthly statistics. Biological studies may use typically archived statistics or work with climatologists to have more biologically meaningful outputs saved or extracted from GCM runs.
1. How do GCMs represent atmospheric and oceanic circulation?
GCMs represent atmospheric and oceanic circulation in the way that there is a series of equations describing physical properties of gases and fluids. Each set of equations is solved for a volume of air or warmer, typically with dimensions of hundreds of kilometers. The atmosphere and oceans are represented by thousands of these cubes.
1. Our climate has become relatively stable during the last approximately 10,000 years. Is this current climate unusually warm, cold, or neither, compared to climates on Earth in the past?
Glacial conditions have dominated this period, with warm greenhouse intervals coming at roughly 100,000-year intervals and lasting only a few thousand years each. This period has been characterized by much climatic variability... unusually warm.
1. What two basic physical sciences do we rely on to predict (simulate) future effects of the build-up of greenhouse gases?
Global Climate Models (GCM's) and local climate models (LCM's)
1. What portion of the electromagnetic spectrum of radiation from the sun do greenhouse gases absorb?
Greenhouse gases absorb, UV radiation, infra-red radiation, and visible. In that order.
1. Provide some examples of specific GCMs.
Hadley Centre in Britain is a well-known weather service in the UK. National Center for Atmospheric Research in Boulder Colorado. The Canadian Climate Model produced by a research group at the University of Victoria. The GFDL model created by NASA's general fluid dynamics lab, and the CSIRO GCM run by the commonwealth scientific and industrial research organization in Australia.
1. What do we mean when we say a gas is a potent greenhouse gas?
How well they are absorbed/ absorb infra-red (UV) radiation. A ranking of potency from highest to lowest goes, chlorofluorocarbons, nitrous oxide, methane, CO2.
1. CO2, methane, nitrous oxide, and chlorofluorocarbons are greenhouse gases. Rank these gases from most potent to least potent. Rank these gases from highest concentration to lowest concentration in the atmosphere.
How well they are absorbed/ absorb infra-red (UV) radiation. A ranking of potency from highest to lowest goes, chlorofluorocarbons, nitrous oxide, methane, CO2. Concentration in the atmosphere is that same list but reversed.
1. Why is it important to try to maintain natural systems, even in the face of climate change?
Human development depends on healthy natural systems. People increasingly turn to nature for inspiration and to the outdoors for recreation, as well as relying on myriad natural systems for provision of food and materials. Maintaining healthy systems is an immense challenge when those systems change rapidly as they are today.
1. In what sense does climate change biology use insights from various disciplines, but not all of the results of the disciplines themselves? Explain with examples.
In a great sense climate change biology uses insights from various disciplines. These disciplines include paleoecology, global change biology, biogeography and climatology. Climate change biology uses insights from all of these disciplines but not all of the results of these disciplines. Like paleoecology data that helps us understand how biological systems will respond to anthropogenic climate change are a major part of climate change biology, but many aspects of paleoecology may remain outside of the realm of the new discipline.
1. Based on available data, what are we likely to see over the next 10,000-30,000 years, increased warming or an ice age? Explain.
In the next 10,000-30,000 years we are an expected to be in an unusually long interglacial period, therefore not another ice age. We are likely to stay in this period of warming for actually an extended period of time due to the current position of Earth's orbit we are in.
1. Explain the process of thermohaline circulation.
In the ocean, the equator to pole circulation is the thermohaline circulation. It is more complex because it must work its way around land masses and because it involves salinity as well as warmth. Warm water at the equator evaporates leaving behind water that is both warmer and more slaty and hence more dense. This salty warm water moves toward the poles where it cools and sinks renewing the circulation. Especially strong in the North Atlantic called the gulf stream. Changes in thermohaline circulation are important triggers for climate change.
1. How is the difference method of downscaling implemented?
Involves Smoothing and interpolation. In this process, present climate data are interpolated to a desired scale, such as 1 km. The difference between present and future GCM simulations is then added to the interpolated current climate data yielding a future climate surface at the desired scale. It subtracts the present value for a variable of interest, such as temp, that a GCM projects from the future projected value. This difference is then added to current observed climate for that variable to obtain an estimate of possible future values.
1. What does the term El Niño/Southern Oscillation (ENSO) refer to?
It is referring to the complement to el nino conditions being la nina events. This causes upwelling the pacific and how it is enhanced and rainfall is reduced. The oscillation between these two conditions is known as the el nino/southern oscillation or ENSO. This is directly linked to the teleconnection relationship that comes as a result of el nino.
1. In the context of a RCM, what are the "boundary conditions," and from where does information about boundary conditions for a RCM come?
It needs information about its neighboring cells. For instance, an RCM cannot simulate orographic rainfall unless it knows the amount of moisture entering the region. These neighbor cell conditions, or "boundary conditions" are provided by GCM in which the RCM is embedded.
1. Water is the most abundant greenhouse gas in the atmosphere, and it is produced in the combustion of fossil fuels, but it is not a major contributor to the greenhouse effect. Explain the apparent paradox.
It stays in the lower atmosphere when it is released in the combustion of fossil fuels. The magic happens in terms of climate change and warming in the upper atmosphere. This is why although it is a greenhouse gas, it has an overall low effect on warming.
1. Explain what La Niña events are
La nina events are upwelling in the pacific is enhanced and the rainfall around the pacific regions is reduced.
1. What factors cause the major ocean circulation patterns?
Major ocean circulation patterns follow the wind patterns, forming large gyres with eat to west flow along the equator and west to east flow at the midlatitudes. However, ocean current directions varies from wind direction by 15-45 progressively with depth an effect known as the Ekman spiral.
1. How many GCMs exist, and how do they differ?
Many GCMs exist, but they all use similar suites of physical equations but differ in the specifics of particular equations, complexity and treatment of parameters.
1. Provide a brief overview of the evolution of GCMs.
Models of global climate began as mathematical description of atmospheric circulation. They were known as general circulation models or GCMs. As the models became more complex, layers of ocean were added, they are known as coupled atmosphere ocean GCMs. Today most GCMs are AOGCMs. More advanced versions have vegetation, joining models of the biosphere to the ocean atmosphere models. These most advanced models are known as earth system models.
1. What are the natural drivers (forcings) of the Earth's climate?
Natural forcing's are natural things that are affecting Earth's climate change. Some of these things include, orbital variations, volcanoes. They modify summer climate on shorter timescales.
1. Does it make sense to run a RCM for one particular region by itself? Explain.
No it does not. The most common way to run an RCM is to embed an RCM into a GCM. The RCM then takes coarse resolution GCM inputs at edges and turns them into a finer scale regional climate simulation.
1. How can RCMs be used in a way that takes into account information from neighboring regions?
No it does not. The most common way to run an RCM is to embed an RCM into a GCM. The RCM then takes coarse resolution GCM inputs at edges and turns them into a finer scale regional climate simulation.
Obliquity:
Obliquity: Amount of tilt Earth has on its axis
1. What is the chemical effect of higher [CO2] in the atmosphere on land plants?
On land, CO2 stimulates plant growth because it is one of the principle inputs to photosynthetic pathways. This effect is not uniform for all species, and it may favor plants using the C3 photosynthetic pathway. Global vegetation patterns may therefore be influenced by direct CO2 effects as well as by warming. The complex, long term effects of CO2 either in the oceans or on land are yet to be fully understood.
Precession
Precession: Direction of tilt of Northern hemisphere toward the sun
1. Most of the increase in the [CO2] in the atmosphere during the past century has originated from human activities. What are these activities?
Primarily due to the burning of fossil fuels. Beginning with coal at the outset of the industrial revolution, and transitioning to oil and natural gas.
1. What constraint does the difference between RCMs and GCMs impose on the use of RCMs? Why?
RCMs cannot be run alone because they must be connected to other regions in some way.
1. The Intergovernmental Panel on Climate Change (IPCC) has developed representative concentration pathways (RCPs) to help study the anticipated impacts of CO2 emissions and other activities on climate change. Name and explain the most commonly used RCPs in climate change assessments.
RCP's allow assessment of the implications of a range of possible pathways, including overshoot scenarios in which global greenhouse gas concentrations exceed a policy target. They represent atmospheric greenhouse gas concentrations resulting from possible differences in future emissions.
1. What is the difference between regional climate models (RCMs) and GCMs?
Regional climate models are finer scale GCMs specifically of changes in particular regions. The equation based processing, cubes, and layers of the GCM are all present in an RCM but at a finer scale. The scale of an RCM is measured in tens of kilometers as opposed to hundreds of kilometers.
1. Why is sea-surface temperature so important?
SST drives many climatic phenomenon and is important because oceans comprise 2/3 of the Earth's surface and what happens at the air water interface influences much of what happens near the habitable surface of the planet. It strengthens hurricanes and determining height of tropical cloud formations.
1. What does Figure 2.20 indicate about the role of human-induced changes in mean temperature?
Shows the world wide natural and human forcings and how they have impacted each continent/ major country. This is real measured data so it's far harder to dispute for disbelievers of climate change.
1. Explain the positive feedback loop in Earth's climate system between global temperature and area of ice and snow.
Snow and ice are particularly important parts of the Earth's surface in the climate system because they reflect the sun well. White surfaces reflect solar energy colling the Earth's surface. Glaciers, snowpack, and sea ice all measurably cool the Earth by reflecting sunlight. Increases in average global temperature reduce the area of ice and snow by melting, thus reducing the resultant reflectivity of the planet and producing a positive feedback loop in the climate system as the Earth warms still further. Positive feedback loop: now and ice reflect light which is a measure of albedo/ light colored materials have a high albedo and dark material have a low albedo. The near white of snow and ice gives them a high albedo, whereas the dark waters revealed when ice melts or the dark needles of the forest conifers revealed when snow melts have a low albedo. This accelerates warming.
1. Explain the "greenhouse" effect.
Some of the gases in the Earth's atmosphere trap heat. Sunlight warms the Earth's surface, which then radiates long wave radiation. Some of this radiation is absorbed and reemitted by gases such as CO2 and water vapor. Part of the reemitted radiation is directed back at the Earth which results in a net redirection of long wave radiation from space and back to Earth. This warms the lower reaches of the atmosphere, much as glass in a greenhouse traps heat from the sun, so is known as the greenhouse effect.
1. Give an example of how climate change may be manifested as regional cooling, not just warming.
Some regions have cooled whereas most have warmed. Cooling and warming trends are sometimes found in close proximity. Areas of antarctica for instance, have warmed as much as 2.5 C, whereas other areas of the continent have cooled slightly
1. What is the so-called "seesaw" effect at the scale of the northern and southern hemispheres?
Southern vs. Northern Hemisphere one reflecting while one absorbs via plants. Alternately impacting what is reflected into the atmosphere. Teleconnections are disrupted across equator so each hemisphere is doing its own thing.
1. What is statistical downscaling?
Statistical downscaling uses observed relationships between large scale climate phenomenon and local conditions to generate fine grain projections from GCM output.
1. The sudden change in climate that occurred during the Younger Dryas was due to a breakdown in the thermohaline circulation. What other causes of rapid climate change might there be?
Sudden releases of greenhouse gases such as CO2, or methane.
1. What are teleconnections in the context of global climate?
Teleconnections are long-distance linked impacts that are not random; they tend to be linked to complementary sister states. They often involve coupled changes in ocean and atmospheric states
1. How does energy from the sun get trapped near the Earth's surface?
The atmosphere traps energy by capturing and reradiating radiation that would otherwise escape into space. Long wave radiation given off by the land surface and oceans is absorbed by greenhouse gases in the atmosphere. This energy is then reradiated in all directions, the net effect being a trapping of a portion of the energy in the Earth's atmosphere near the surface. Clouds in the atmosphere can reflect incoming solar energy, cooling the surface. During the day, this outstrip the warming effect of the water vapor in the clouds, whereas at night the warming effect of clouds dominates.
1. What is the likely cause of the seesaw effect at the scale of the northern and southern hemispheres?
The cause of the seesaw is most likely decoupling of climate connectivity across the equator. Circulation features such as Hadley cells originate at the equator, so there may be a delay in transmitting large changes across this boundary. Alternatively the circumpolar current in Antarctic could be barrier to change and the Antarctic climate may be out of such with the rest of the planet it has even been suggested that large abrupt change may originate in the tropics.
1. Why is the difference method used to get projections?
The difference method is used because GCMs do not faithfully reproduce present climate at fine scales, so comparing future GCM projections to observed climate may result I errors. The method takes the amount of change from the GCM but the spatial and temporal variability from observed climate.
1. What are the major and dynamic elements of Earth's climate system?
The dynamic elements include, hydrology and the movement of gases, including water vapor. The Earth's climate system is composed of the atmosphere, the oceans, and the Earth's land surface.
1. What are the fundamental reasons that climate affects species?
The fundamental reasons that climate affects species are, species are adapted to their niche or ecological role. This means they have adapted to specific temperatures, precipitation levels, etc. When climate effects these conditions it affects the associated species drastically. A good example of this is coral. Minor temperature changes result in death of species.
1. What gases are the main constituents of the atmosphere?
The gases that are the main constituents of the atmosphere include, nitrogen (78%) and oxygen (21%).
1. How does the land surface influence how the Earth warms?
The land surface influences how the Earth warms in the way that, land surface consists of vegetation exposed soil and rock, human structures and snow and ice. The reflective properties of these surfaces make a large difference in how the planet warms. Dark surfaces absorb solar energy and reradiate it as heat that may be trapped by greenhouse gases in the atmosphere. Light surfaces reflected sunlight back into space in wavelengths not trapped by greenhouse gases so they have a colling effect.
1. What other factors significantly influence our climate that are external to our climate system?
The major elements include, sun, variations in the Earth's orbit in relation to the sun, and the shape and position of continents and oceans.
1. What general roles does the ocean play in our climate system?
The ocean are the second major component of the oceans is as vast reservoirs of water and dissolved gas. The oceans contribute most of the water vapor found in the atmosphere. Warmer oceans give off more water vapor. They also produce larger and more severe storms such as hurricanes. They also absorb CO2 reducing its concentration in the atmosphere.
1. What is the source of energy that drives Earth's climate system?
The source of energy that drives Earth's climate system is, energy from the sun. The sun's warmth is unevenly distributed across the planet, which sets winds and ocean currents in motion, transporting heat from the equator to the relatively cooler poles. Energy from the sun drives the hydrologic cycle as well, evaporating water from the oceans and freshwater bodies.
1. Explain why the speed of temperature change varies with topography.
The speed of temperature change varies with topography because on a perfectly flat smooth Earth, maintaining a constant temperature requires shifting north or south with latitude toward the cooler poles to offset warming. The latitudinal shift sets the velocity of climate change in areas with little topography. In mountainous areas, a similar temperature change can be achieved by shifting upslope and these distance are much shorter. In the real world, with topography flat areas have a HIGH velocity of climate change and mountains have a LOW velocity of climate change.
1. What is climate change biology? Give me a brief definition.
The study of the impact of climate change on natural systems, with emphasis on understanding the future impacts of human-induced climate change. The scope of the discipline encompasses all of the effects of human greenhouse gas pollution on the natural world. It links climate systems and biological systems. Includes things like ecosystem habitability and biologically created emissions.
1. What gases are the most abundant greenhouse gases in the atmosphere?
The two most abundant greenhouse gases in the atmosphere are H2O (water vapor) and CO2 (carbon dioxide). They are both transparent to visible light arriving from the sun, but each traps heat coming from the Earth's surface. Both occur naturally but CO2 is a lso released by human burning of fossil fuels.
1. Are these three solar forcings affecting primarily the distribution of heating between seasons or between hemispheres, or primarily the overall amount of solar energy reaching the Earth?
These effect heat during seasons greater than solar overall energy reaching Earth. They strongly affect the distribution of heating between seasons or between hemispheres more strongly than they affect the overall amount of solar energy reaching the Earth. Their effect on climate is therefore due to amplifications and dynamic effects rather than to changes in raw energy input.
1. Why are these emissions driving major changes in climate?
These emissions have massive effects on the global carbon cycle and are driving major changes in climate. Carbon cycle changes are important because they affect the balance that determines concentrations of CO2 in the atmosphere and hence climate change.
1. What are Hadley cells?
They are circulation patters and there are two Hadley cells between the equator and south pole. Hadley cells have both vertical and horizontal structures. Viewed in cross-section, air masses in a Hadley cell rise at the equator, move toward the pole, and then descend.
1. What are the Milankovitch cycles?
They are cycles in orbital forcings. They recognize that cool summers are key to ice buildup. They show that low obliquity brings cool summers to both hemispheres, which favors ice buildup in the north and intensified circumpolar current in the south. The intensification f the circumpolar currents reduces upwelling of CO2 rich water. The reduction in atmospheric CO2 cools the planet facilitating continental ice sheet buildup in the north. And vice versa.
1. What role does the southern hemisphere play in the formation and termination of glacial periods?
They show that low obliquity brings cool summers to both hemispheres, which favors ice buildup in the north and intensified circumpolar current in the south. The intensification f the circumpolar currents reduces upwelling of CO2 rich water. The reduction in atmospheric CO2 cools the planet facilitating continental ice sheet buildup in the north. The southern hemisphere may also push the northern hemisphere along as glacial periods end—high obliquity results in warmer summers in both hemispheres. This begins to melt the continental ice sheets in the north, whereas in the south it intensifies circumpolar currents and winds pumping CO2 rich water to the surface and warming the planet.
1. GCMs use cells that are too big (coarse) to capture physical patterns and processes that are important in a region. How is this problem circumvented?
This is circumvented by using RCM's. RCMs operate in the same principle as GCMs but with cells of considerably smaller dimensions—typically 10-80 km on a side. Because the dimension is squared to get the area of the cell, and cubed to get its volume, an RCM at 50 km has more than 100 times greater resolution than a GCM at 300 km
1. If global warming led to a northward shift of conifers into areas that were previously tree-less tundra, what effect might this have on climate warming? Why?
This might have a fairly drastic effect on climate warming. This is because replacement of tundra with coniferous forest owing to climate warming is darkening boreal latitudes, increasing heat absorption and causing further warming. This moisture transpired by trees in one area of the amazon condenses in the atmosphere and falls as rain in other areas of the amazon.
1. In part, the discipline of climate change biology seeks to understand future impacts of human-induced climate change. What information does the discipline use to understand these impacts?
To understand future change, the discipline draws on lessons from the past, currently observed changes, biological theory, and modeling.
1. What factors cause the trade winds?
Trade winds are surface winds caused by air movement and Hadley cells being deflected by the Coriolis effect. They move westward along the equator in both the northern and southern hemisphere. Where the trade winds converge along the equator a zone of uplift and cloud formation results, which is known as the intertropical convergence zone (ICTZ). The trade winds are balanced by return flows in the midlatitudes by west to east blowing winds known as the westerlies.
1. What causes upwelling?
Upwelling results when along shore winds move ocean water. The wind driven surface movement is deflected by the Ekman spiral resulting in transport of water away from the coast. This moving water has to be replaced so water from depth is drawn to the surface. The movement of this cold nutrient rich water from depth to the surface is referred to as upwelling.
1. Why is knowledge about the velocity of climate change important?
Velocity of climate change matters to living things especially plants. Plants are mobile only when seeds disperse which makes keeping up with the velocity of climate change very difficult. Understanding the velocity of climate change and its interplay with species dispersal is therefore important to understanding both past and future range shifts.
1. Have warmer periods in Earth's history been associated with higher or lower levels of atmospheric CO2?
Warm periods have been repeatedly associated with high levels of atmospheric CO2 during ice ages of the past 2 M years. Deeper in time, period of high CO2 concentrations or methane release have been associated with global warm periods.
1. Which atmospheric gases are important greenhouse gases (gases capable of absorbing heat energy)?
Water vapor and CO2 are minor constituents of the atmosphere but potent greenhouse gases.
1. What is coral bleaching?
When coral is met with increasing temperatures they expel their zooxanthellae. Without the photosynthetic pigments in zooxanthellae coral loses its color and the only thing visible is the calcium carbonate skeleton because now there is nothing to photosynthesize and pass nutrients to the coral and it appears white or bleached.
1. Is there any evidence that species' interactions are shifting due to climate change?
Yes! A very important example of species' interactions shifting due to climate change is seen in the symbiotic relationship between zooxanthellae and coral and how with increased temperatures, there is an expelling of zooxanthellae from coral which causes coral bleaching which is vastly hurting coral reefs.
1. Is the rapidity of climate change related to the velocity of temperature change? Explain.
Yes. Another way to look at the rapidity of climate change is the velocity of temperature change. The velocity of climate change is proportional to the distance that has to be traveled over the surface of the Earth to maintain a certain temperature as climate changes.
1. Is there any evidence that species' niche space (locations where species can live) has shifted in response to climate change?
Yes. The aforementioned evidence is known as niche tracking and range shifts. Often associated with moving farther north as a result of warming.
1. Generally define an organism's niche.
A plants or animals address. It is the combination of conditions in which they can survive and reproduce. This address is called their niche. Organisms cannot survive outside of their niche
