Ecological Responses to Global Climate Change: Exam 1

What are some greenhouse gases (other than CO2), are their atmospheric concentrations changing, and how are they connected to human population , agriculture, or industry?

• Nitrous oxide comes from poor soil management, where the nitrogen in fertilizers is released into the air; from transportation pollution; and from some industrial processes. 5 • Perfluorocarbons (PFCs) come from the manufacture of aluminum, solvents and plasma. • Sulfur hexafluoride (SF6) comes from the production of magnesium. • Tropospheric ozone is produced by air pollution by transport and industry • Water vapor is caused by evaporation of the world's oceans. It is the primary natural greenhouse gas, but it is not being increased by human activity in sufficient quantity to make any difference.

Define phenology

"The seasonal timing of life cycle events". The timing of spring plant development = most sensitive and easily observed indicator of the biotic response to climate change.

What causes climate?

(1) changes in ocean temperatures. (2) changes in terrestrial geomorphology and ecosystems, including human activities (impervious surfaces). (3) changes in the earth's orbital geometry. (4) volcanic activity with increased atmospheric dust and reduced sunlight penetration (clouds). (5) variations in solar radiation. (6) increases in atmospheric gases that absorb heat energy. (including greenhouse gases).

What are some ways by which organisms and ecosystems can cope (or not cope) with climate change, and what kinds of information do we have on how organisms have fared following past changes in climate? What kinds of ecological effects may result from a change in climate?

A long term change in mean temperature can have large effects, even if the change in the mean is small relative to short term variation. For example: • The 'Medieval Optimum' (in Europe) was only 0.5oC warmer than typical, but caused drought in the SW US longer and deeper than any in recent history (temperature and precipitation are linked). • 20,000 years ago at the end of the last Glacial Maximum, ice covered huge portions of N.America at depths comparable to parts of the Greenland Ice Sheet. It was only 5-6 oC colder than now. Over the past 10,000 years, mean surface temperature for the entire earth has been about 57oF or 13oC. A change of 0.8oC (as already measured since the industrial revolution) is a change of 6.1%. The earth's temperature is an equilibrium system maintained by feedbacks, just as your body is. If your body was this far out of equilibrium, your temperature would be 104.6. A change of 3.4oC is 26%, which represents a major shift in abiotic conditions. A shift of 7 this magnitude and speed is unprecedented... smaller and slower shifts caused major extinction events.

Name and Describe the 4 types of weather systems present on planet Earth.

Air masses. Types of weather fronts (cold, warm). Traveling cyclones and anticyclones. Tropical Weather Systems.

There are many potential causes for variation in climate (temperature in particular). Albedo is one. Provide a definition for albedo, briefly summarize why it's important, being sure to include a diagram indicating albedo's role within a feedback loop.

Albedo is defined as the ratio of diffusely reflected to incident electromagnetic radiation. Albedo is known as surface reflectivity of sun's radiation. 8 The proportion of absorbed, emitted, and reflected incoming solar radiation steers the Earth's climate system causing fluctuations in temperature, winds, ocean currents, and precipitation. The climate system remains in equilibrium as long as the amount of absorbed solar radiation is in balance with the amount of terrestrial radiation emitted back to space. DiagramIf a snow-covered area warms and the snow melts, the albedo decreases, more sunlight is absorbed, and the temperature tends to increase. The converse is true: if snow forms, a cooling cycle happens. The intensity of the albedo effect depends on the size of the change in albedo and the amount of insolation; the resulting incoming energy is then used to heat the land and oceans and drive the hydrologic cycle.

Identify and describe (give examples) of population responses to climate change

Change in timing (phenology). Change in location (range shifts). Adapt (over generations). Die / Go extinct.

Whats dendrochronology and how does it help for determining past climate?

Dendrochronology (tree-ring dating): Trees in temperate zones grow one ring per year. A year-by-year record or ring pattern is formed that reflects the climatic conditions in which the tree grew. These patterns can be compared with other trees growing in the same geographical zone and under similar climatic conditions. The sum of these tree-ring patterns forms a chronology against which old wood can be crossdated and the chronology extended back in time. In areas where the climate is reasonably predictable, trees develop annual rings of different properties depending on weather, rain, temperature, etc. in different years. These variations may be used to infer past climate variations.

What evidence links global temperatures and atmospheric carbon dioxide concentrations?

Climate may change from age to age however, the warming trend of the last century is 4 unprecedented in the historical record and clearly results from human activities. By studying ancient Antarctic ice cores, scientists have mapped temperatures and carbon dioxide levels over the past 800,000 years. These records clearly show that greenhouse gases have amplified natural warming cycles. Since the Industrial Revolution, carbon dioxide levels have jumped from 280 parts per million (ppm), a level characteristic of the interglacial periods, to about 411 ppm at the end of 2021. Temperatures on Earth also began to rise. The first decade of the 21st century was the warmest ever recorded. There is good evidence that current climate change is due to anthropogenic release of CO2 into the atmosphere. Based on 15 well-tested models considered by the Intergovernmental Panel on Climate Change, a doubling of atmospheric CO2 would yield an increase in global mean temperature of ∆T2X = 3.5oC (6.7 oF, with 95% confidence limits of 1.9oC - 4.1oC, or 3.6 - 7.8oF). IPCC considers only peer-reviewed science, and these models do well at: (1) predicting past climates (hindcasting) for data not used to develop the model, and (2) predicting changes in climate for the period since they were developed (Mean global temperature has already risen 0.8 oC in just over a century, with recent increases tracking the predictions of the models). (3) accounting for known climate forcings, which are factors that by logic should alter temperatures, such as solar intensity or volcanic activity.

How much is climate likely to change over the 21st century, according to the IPCC's most recent range of projections for emissions of atmospheric CO2?

Earth's average temperature has risen about 1 degree F in the past 100 years and the IPCC projects global temperature increases of 3 to 10 degrees F in the next 100 years and says that human activity is the cause of most of the observed and projected warming. This is for 'business as usual' models of human population growth, economic development and energy production. IPCC is the UN-coordinated international scientific advisory group for the Framework Convention on Climate Change. FCCC is the international group that implements the Kyoto Protocol, which originated at the Earth Summit in 1992, in Rio de Janeiro. The Kyoto Protocol aims to reduce CO2 emissions, but its targets are much too limited to have much effect on eminent changes.

What are greenhouse gases? Provide at least 3 examples and explain their role.

Gases that trap heat from leaving the earth's atmosphere. Water vapor, CO2, CH4, N2O, CFCs, and HCFCs. Water vapor - contributes the most to the greenhouse effect and occurs in the atmosphere as result of the natural cycle of water. Carbon dioxide (CO2) - also cycles naturally between the atmosphere and living organisms. Also cycles back and forth between water on the Earth's surface (freshwater and the oceans) and the atmosphere. Humans release large quantities of CO2 to the atmosphere by burning fossil fuels, deforestation, and other industrial processes. Methane (CH4) - is a natural byproduct of decomposition, but significant quantities are also produced via agriculture and animal husbandry as well as by fossil fuel production. Nitrous oxide (N2O) - is released naturally from terrestrial soils and oceans, but substantial quantities are also generated from the use of nitrogen fertilizers in agriculture and through some industrial processes. Other gases - Other natural and man-made gases also contribute to the greenhouse effect, including tropospheric ozone, and industrial gases such as halocarbons. Aerosols (Not GHG exactly) - are airborne particles within the atmosphere. Some aerosols, such as sulfate aerosols and black carbon aerosols are also produced by fossil fuel combustion.

What is the greenhouse effect and is it a new phenomenon?

Global warming is caused primarily by carbon dioxide from burning coal, oil, and gas. Certain gases, that trap heat are building up in Earth's atmosphere. The primary culprit is carbon dioxide, released from burning coal, oil and natural gas in power plants, cars, factories, etc. (and to a lesser extent when forests are cleared). The second is methane, released from rice paddies, both ends of cows, rotting garbage in landfills, mining operations, and gas pipelines. Third are chlorofluorocarbons (CFCs) and similar chemicals, which are also implicated in the separate problem of ozone depletion. Nitrous oxide (from fertilizers and other chemicals) is fourth. But CO2 is the main driver. Can see this from data sets that relate temperature and atmospheric composition over time (e.g., ice core data).

One proxy for estimating paleotemperature involves using oxygen stable isotopes. Describe the ratio method used to determine the so-called d18O, specify the relationship between d18O and temperature, and list one physical property that impacts d18O values.

Ice cores previously retrieved from both Arctic and Antarctic ice sheets have used stable isotopes of water 18O/16O and/or D/H, expressed as d18O and dD (‰)) to evaluate past climate fluctuations. The temperature- d18O relationship originally proposed by Dansgaard (1964) forms the basis of this relationship, however there is a growing body of research suggesting that timing of precipitation, changing vapor mass trajectory, and post-depositional modification can complicate this. The ice d18O-temperature relation is positively correlated, i.e., warmer temperatures during precipitation lead to higher d18O values. This is opposite to the fractionation behavior during the formation of carbonates, where increasing temperatures lead to decreasing d18O. Physical properties: evaporation and precipitation were the big two we mentioned.

Identify and describe the two physiological indicators of thermal stress.

Levels of ubiquitinated proteins: Ub proteasome pathway rids cells of denatured proteins. "The garbage disposal of the cell". Direct measure of irreversible protein loss to the organism. Use Ub conjugate specific antibodies. Levels of heat shock proteins: Hsps as chaperones, rescue some proteins. Help ameliorate loss of proteins. Indirect measure of thermally-induced denaturation pressure. Use antibodies and other techniques to measure Hsp levels.

Discuss both manners in which a population can gain entrance to a new habitat. Mention all four characteristics in which the population might become established.

May immigrate from neighboring area. May be introduced by Humans, Weather event and Currents. For establishment a population: Must find new habitat appropriate; Must compete well with native species; Must have adequate food; Must not be preyed upon too much.

Discuss the three factors that affect climate and give an example of each.

Our atmosphere is made up of gases, such as nitrogen, oxygen, and CO2, and water vapor, which act like a "blanket" draped around the planet. Some of these gases—such as CO2, water vapor, and methane—absorb heat, reducing the amount that escapes to space, and increasing global temperatures. This is what is called the "greenhouse effect," and these gases are often referred to as "greenhouse gases." Without this process, the temperature of Earth's atmosphere would average about 30 degrees Celsius (50 degrees Fahrenheit) colder than it is today, making it difficult for Earth to sustain life as we know it. However, if this blanket were to become too "thick," with too many gases trapping too much heat, Earth would be uninhabitable. In the atmosphere of Venus, for 2 example, a buildup of carbon dioxide has led to a broiling temperature of 500 degrees Celsius. Some scientists continue to believe that global warming could be due to changes in sunspots, natural cycles of warming and cooling, or other factors, most scientists who study this issue now agree that it's extremely unlikely that these changes in temperature are wholly natural in origin. Instead, they believe the warming we are experiencing today is due to rising concentrations of heat-trapping gases that form a "blanket" around Earth. These gases are put into the atmosphere primarily by human activities—particularly the burning of fossil fuels

Describe a positive feedback loop and give an example of how one could lead to global warming.

Positive feedback- imposed change causes further changes in the same direction; Warming leads to more warming; DESTABILIZING

Name 3 of the 4 forces driving wind circulation

Pressure Gradients; Coriolis; Centripetal forces; Friction

What are the effects of thermal inertia?

Smaller organisms (with less "thermal inertia") heat up faster than large organisms, and may get hotter during brief, high temperature events Larger organisms, with a lower SA/Volume ratio, take longer to heat up, but given enough time often heat to higher temperatures.

Recognize this equation? Describe the numeric constants and variables . k=Ae ^-Ea/RT

Svante Arrhenius publishes first calculation of global warming from human emissions of CO2. Calculates that doubling the atmospheric CO2 content would increase the global average temperature by between 5 and 6°C.

What is the difference between weather and climate?

Weather refers to the conditions at a specific time and place, and can change from hour to hour, day to day, and season to season. Climate, on the other hand, refers to the long-term average pattern of weather in a place. For example, we might say that the climate of South Florida is warm, moist, and sunny although the weather on a particular day could be quite different than that. Long-term data are needed to determine changes in climate, and such data indicate that Earth's climate has been warming at a rapid rate since the start of intensive use of coal and oil in the late 1800s.

How have humans influenced the global climate cycle? (Consider fluxes as well as compartment sizes.)

The primary driver of anthropogenic climate change is CO2. There are important other drivers: 3 • methane (contributes to warming, one molecule of CH4 affects temperature more than one molecule of CO2) • particulates (contribute to cooling) • water vapor (contributes to both, depending on altitude and type of cloud). Some 7.2 billion tons of carbon dioxide are being released into the atmosphere every year because of human activities. Cars, power plants, factories, and homes release about 5.5 billion tons of carbon dioxide every year as fossil fuels such as coal, oil, and natural gas are burned to produce energy. Another 1.6 billion tons of carbon dioxide are released by deforestation, especially in the tropics. Some of this carbon dioxide is absorbed by the ocean, plants, and other natural "sinks." But about 3.2 billion tons of carbon dioxide remains in our atmosphere every year. The biggest source of anthropogenic CO2 emission is from burning fossil fuels (coal, oil, natural gas) to produce energy. Almost all energy on earth ultimately comes from the sun. Plants capture that energy by photosynthesis CO2 + H20 + energy «-» CH20 + O2 • If this redox reaction proceeds to the right, it is photosynthesis: storing energy by reducing a molecule of CO2 to produce a carbohydrate. • If it proceeds to the left, it is respiration: releasing energy by oxidizing a carbohydrate, consuming O2 and releasing CO2. Over geological time, plant matter is converted to fossil fuels, with high temperature, pressure and anaerobic conditions. Coal: reduced terrestrial plants, mainly peat. Peat is organic matter that accumulates in soil when plant tissue accumulates (via photosynthesis) faster than it is decomposed to its inorganic components. Oil and natural gas: reduced aquatic plants (mainly algae) and animals that accumulated as ocean sediments, and were geologically subsumed and compressed. Oil is lighter than the water that saturates permeable or porous rock, so it works upwards. Oil deposits accumulate where porous rock is capped by impermeable rock. Most plankton do not end up in the sediments - they are consumed by other organisms. Consequently, only highly productive ocean waters produce enough organic sediment to allow oil to form - these are mainly nearshore. Sediments that support oil formation also require waters to with low oxygen content (anaerobic). Natural gas is mostly methane, formed as a by product of the conversion of organic sediment into oil, so natural gas deposits usually are found in the same rock layers as oil. The conditions for oil formation are narrow, so oil deposits are geographically restricted.

Global climates have changed as much (or more) in the past, but something is different about the climate change likely to result from increased greenhouse gas concentrations versus climate changes of the past. What is this difference, and how is it likely to affect the ability of organisms and ecosystems to "cope with" this change?

While Earth's climate has changed naturally throughout time, the current rate of change due to human activity is unprecedented during at least the last 10,000 years. The projected range of temperature rise is wide because it includes a variety of possible future conditions, such as whether or not we control greenhouse gas emissions and different ways the climate system might respond. Temperatures over the US are expected to rise more than over the globe as a whole because land areas closer to the poles are projected to warm faster than those nearer the equator.

Scientists on the United Nations Intergovernmental Panel on Climate Change have studied the global sea level, and they say it will rise by up to a meter by 2100, because of climate change. Which of these four reasons do they say is the reason for this rise in sea level?

a. The expansion of the water molecules in the sea, which is caused by the higher temperature of the water. b. The increase in fresh water that is running into the oceans, as a result of increased rainfall around the world. c. The melting of the Greenland and Antarctic ice caps. d. The melting of the Arctic ice cap. C

As the temperature warms, the permafrost that covers most of the Arctic and northern lands melts. Which of these four impacts is being caused by the melting permafrost?

a. The ice-roads which people use to cross lakes and rivers in the winter are melting earlier, and must be closed, since they are no longer safe. b. The large quantities of methane gas from ancient rotting vegetation that is stored in the permafrost is escaping and may explode in a dangerous manner. c. The land underneath houses, roads and bridges, is collapsing causing them to buckle and become dangerous. d. It is becoming more dangerous to travel over land by snowmobile, since there are frequent patches of water and bare earth where there used to be snow.

If global warming continues, the summer ice on the Arctic Ocean could be all gone by 2050, and the year-round ice by 2100. This will affect the polar bears in various ways. Which of these four effects will be the most serious and life threatening to the bears, as the ice melts?

a. There will be a shorter season when they can hunt for walrus, so the bears will slowly starve to death. b. The increased rain and warmer temperatures will cause the snow dens where the female raise their cubs to collapse, while the cubs are still very small and vulnerable. c. There will be a shorter season when they can hunt for ringed seals, so the bears will slowly starve to death. d. There will be fewer tourists standing around on the ice, making for easy prey, so the bears will slowly starve to death.