GEOG 104 Midterm
Yes, as much of this recent increase in Atlantic hurricane activity began in 1995 as the tropical North Atlantic warmed and atmospheric conditions became conducive for increased hurricane activity, similar to the mid-20th Century Atmospheric heat increases temperature in the ocean and warm water is fuel for hurricanes (the upper ocean surface temperature once they reach 80 d/F they provide a warm moist atmosphere for hurricanes)
According to models, will hurricane frequency increase due to greenhouse warming?
unclear? the average intensity of tropical cyclones to increase by up to 10%
According to models, will hurricane intensity increase due to greenhouse warming?
response to the perturbation pushes the system in the same direction as the perturbation (if the temperature cools/warms for ex.). It's accelerating the cycle e.g. melting permafrost due to climate change -> creates wetlands which release GHGs into the air (e.g. methane) -> speeds up global warming -> more melting permafrost
Amplifying (positive) feedback
Changes in the wind, warmer SST (including warmer tropical north Atlantic SST), increased thunderstorm activity
Apart from greenhouse warming, what other influences are there on Atlantic hurricanes?
the non-breeding period, external force imposed on ecological systems, environmental change and population dynamics
Biological and environmental factors impacting Adelie penguin population size
The more GHG, the higher the global temperature. When it gets absorbed into the earth the radiation are short-wave radiation and it is able to pass through GHG no problem, but when it reemerges and reflects into space, it has changed into long-wave radiation which is blocked by GHG and reradiated back into the earth/trapped
CO2 and energy in the atmosphere
(of a region) typically characterized by the long-term average of weather conditions (globally) characterized by the global average temperature. Also, time and space patterns of precipitation, temperature, and wind
Climate (vs weather)
occurs when the patterns change in time (e.g. winter months get warmer) and space (e.g. monsoon rains occur further south) e.g. sea level rise, lasting drought conditions, lasting increase in surface temperature
Climate change
Model showed that Florence would end up being bigger than it would have been if it occurred in a world with no human-caused warming. A warmer sea surface and more available moisture in the air — both due to climate change — also point to Florence dumping 50 percent more rain on parts of the states of North and South Carolina.
Climate change as a factor in the occurrence of recent devastating hurricanes
feedbacks both respond to temperature changes and, in turn, influence temperature Inflow from snow -> stock of ice -> outflow from melt
Climate change feedback link stocks and flows
the components of the Earth system that respond to and play a role in climate change. Includes the atmosphere, the hydrosphere (oceans, rivers, lakes, etc.), the biosphere, the lithosphere (land surface or terrestrial realm), and the cryosphere (ice).
Climate system
the year-to-year changes in the climate of a region. Often causes year-to-year changes from wetter to drier and warmer to cooler e.g. intense heat/cold spell, increased precipitation (amount of snowpack in winter), changes in weather based on geographical location
Climate variability
a system of interacting "spheres" (the cryosphere, the atmosphere, the lithosphere, the biosphere and the hydrosphere) How it's impacted by and impacts those spheres Anthroposphere is how humans are influencing climate
Earth as a system
Positive balance (more energy coming in than going out) -> not at equilibrium incoming: 341.3 - 101.9 = 239.4 W m^2 outgoing: 238.5 W m^2 net absorbed 0.9 w m^2 Earth's energy balance = stock
Earth energy balance
Reflectivity of ice sheet in June 2012 is lower than the average in last decade - implies that 2012 is warmer than usual Size of ice sheet may be decreasing, due to decreasing albedo (ice would absorb more energy, increasing amount of melting) Greater change at lower latitudes
Evidence for Melting Greenland Ice Sheet
Mineral deposits (stock), (rate of) formation of minerals (inflow), mining (outflow) Money in your bank account stock, income (inflow), spending (outflow) Precipitation -> water reservoir -> consumption, irrigation, evaporation
Examples of flow
external forces imposed on ecological systems that cause them to respond with results cascading throughout the food web Effects of regional warming on sea ice, krill, and Adélie Penguin communities of the WAP Air temperature <---> sea ice extent -> krill densities, winter snow -> Adélie Penguin populations
External forces
link stocks and flows, can dampen or accelerate the effects/impacts e.g. body temperature example slide 6
Feedback
the rate at which stuff adds or subtracts from a stock Changes based on flows (inflow, outflow) e.g. apples picked/hour, water melted/month, fish born/year, knowledge lost/decade When inflow = outflow -> stock doesn't change over time, equilibrium or steady state When inflow doesn't equal outflow -> stock does change over time, not at equilibrium or steady state
Flow
Any change in climate (may be temporary or permanent) that is forced to occur because of a change brought on by something outside of the climate system. For example, a change in Earth's orbit would create a forced change in climate.
Forced climate change
some of the infrared (solar) radiation passes through/is reflected by the earth and the atmosphere but most is absorbed and re-emitted in all directions by greenhouse gas molecules and clouds. The effect of this is to warm the Earth's surface and the lower atmosphere
Greenhouse effect
(very effective at absorbing) typically absorb longer wave radiation (which is that emitted form Earth's surface -> earth absorbs radiation from the sun and re-emits the radiation at different wavelengths/in a different form)
Greenhouse gases
Burning fossil fuels, deforestation (inflow) -> atmospheric greenhouse gases (stock) -> afforestation, oceans (outflow) As oceans absorbs CO2, it lowers the pH of the ocean (ocean acidification) which is a big problem for ecosystems, wildlife (and in turn people) More CO2 in the atmosphere, more CO2 being absorbing into the ocean, more CO2 = more heat, which causes oceans to release more CO2
Greenhouse gases in the atmosphere system
The unadjusted record shows an increase in Atlantic hurricanes since the early 1900s When adjusted with an estimate of storms that stayed at sea and were likely "missed" in the pre-satellite era, there is no significant increase in Atlantic hurricanes since the late 1800s
Has Atlantic hurricane activity increased in the long-term record?
the numbers of Atlantic hurricanes and major hurricanes have increased. Much of this recent increase in Atlantic hurricane activity began in 1995 as the tropical North Atlantic warmed and atmospheric conditions became conducive for increased hurricane activity, similar to the mid-20th Century
Has Atlantic hurricane activity increased since the 1970s?
Greenhouse effect -> atmospheric and oceanic circulation -> local climate -> physiology/behaviour and habitat and food resources -> demographic parameters (e.g. age, quantity) -> population dynamics; survival -> distribution area (do they migrate somewhere else, do they stay as a result of changes in the environment, etc.)
How can climate change influence population dynamics?
Scientists model both human and natural factors to determine which best explains the observed climate changes Both natural and human factors are needed to explain the climate change that has already happened Human factors are particularly important in explaining the rapid temperature increase in the last three decades
How can scientists decide which factors are actually responsible for climate change?
forecasting mechanisms (based on the brightness of the Pleiades, the date that it is first visible, its size, and the position of the brightest star), adapted by altering when planting crops to have the best yields
How did Incans try to adapt to climate variations/changes
began with successfully adapting to climate change, but a prolonged drought led to the collapse of their civilisation (likely were victims of long-term climate variability since moisture levels eventually returned)
How did Mayans try to adapt to climate variations/changes
were ultimately victims of long-term oscillations in the climate of the North Atlantic (warming in other parts of North Atlantic while cooling in Greenland, and vice versa)
How did Vikings try to adapt to climate variations/changes
Air bubbles in ice cores retain atmospheric gases present when the ice was formed e.g. it'll tell you how much CO2 was in the air Annual tree rings not only indicate tree ages, the ring width indicates growth spurts due to warmer temperature
How do we study climate?
Energy retention in the atmosphere depends on the abundance and effectiveness of the GHG CO2 contributes the most (despite methane being more effective at trapping radiation, as it is in larger abundance in our atmosphere)
How much does each GHG contribute to climate change?
an organism whose presence, absence, or abundance reflects a specific environmental condition e.g. Adelie Penguin
Indicator species
Only about 50% of the increased CO2 stays in the atmosphere, the rest is absorbed by the oceans and other sinks. CO2 is dissolved in the oceans is forming extra carbonic acid which is causing a decline in pH and other ecosystem problems Human activities : fossil fuel combustion and industrial processes, deforestation, etc.
Is all of the human-caused CO2 in the atmosphere?
Global temperatures Elevation Volume of ice (stock) what is the trend Sea level Average precipitation Compare to anomaly map from other years
More information on the Greenland Ice Sheet
Less heat escapes into space and more is re-emitted back to earth
Natural greenhouse effect vs human enhanced greenhouse effect
caused by increased CO2 in atmosphere Bad on ecosystems that rely on neutral or low acidity environments to survive
Ocean acidification
Variations in the Sun's output of energy Dust and gases from volcanic eruptions
Other factors that can influence climate include
studies the size and age compositions of populations and the environmental processes affecting them Collect and analyse descriptive data : density, abundance, birth rates, death rates Evaluate population changes over time: growth rate, correlations with environmental variables, predictive models
Population dynamics
Different measures of population size can be used depending on the study organism Ecologists can measure: Total number of individuals in the population (abundance) (works for small population sizes) Total number of individuals per unit area or volume (density) Scientists most commonly use abundance of breeding pairs to measure penguin population size over time
Population size
The smaller the wavelength the more powerful generally The sun has different kinds of radiation/wavelengths (many of them being visible) but also has a bunch of UV Earth mostly emits infrared radiation from its surface
Radiation emissions spectra for sun and earth
0.0013 d/C (interglacial period -> between glacial cycles) 0.02 d/C 20x the rate that the earth has warmed in its most significant period of warming (the change is small compared to a glacial cycle, but temperature is increasing at a high rate)
Rate of change of global surface temperatures over the warming period following major ice ages vs in the last 30 years
response to the perturbation that counteracts the perturbation, stabilising the system
Stabilising (negative) feedback
amount or quantity of something residing in a particular place at a particular time Can change, can be gained/lost e.g. apples in a basket, water in a glacier, fish in the sea, people at a party, CO2 in the atmosphere, knowledge in your brain, etc.
Stock
an interconnected set of elements that is coherently organised in a way that achieves something. More than the sum of its parts, have to have stock and flow e.g. solar system, climate system, SFU, our national economy, etc. Not systems: a conglomeration w/o connections (e.g. sand scattered on a road)
System
Winter (June, July, August) serves as a critical times in the life history of a species, which likely dictates the stability of populations ~15% of adult Adélie Penguins do not survive the winter months Fledgling survival is even more variable
The non-breeding period
Changes in the climate system that result from interactions among climate system components. These changes are not forced by anything external to the climate system.
Unforced climate change
greenhouse gases (affected by plants, trees -> photosynthesis), latitude -> distance from equator, altitude, proximity to water bodies, ocean currents, etc.
What are internal factors affecting climate? HOW do they affect climate?
Correlated because the temperature increased as well the occurrence of hurricanes Hurricanes follow the upward trend of sea-surface temperature
What are the relationships between Sea Surface Temperatures (SSTs) and hurricanes?
Reflected solar radiation, infrared radiation emitted from the earth's surface and the atmosphere (outgoing terrestrial radiation)
What are the sources for energy leaving Earth?
Solar radiation, back radiation from greenhouse gases (they re-radiate a lot of the energy back to earth)
What are the sources of energy for Earth's surface?
Latitude, shape of land (mountains, valleys), altitude, population, public awareness, differences in regional climate systems, proximity to water, pollution (e.g. smog can cause local warming), albedo (reflecting power of the land surface, just in terms of its colour e.g. Antarctica)
What can the climate of a particular place on Earth be affected by
solar flares, asteroid impacts, earth's rotations around sun (distance and orientation), human impacts (humans are external to the climate system) -> anthropogenic forcing e.g. greenhouse gases
What determines global average climate? In other words, what things are external to the climate system?
GHGs are molecules that absorb and emit terrestrial radiation (rather than reflecting) at wavelengths that overlap with some of the wavelengths of radiation emitted by Earth (which is infrared) This "surface radiation" is the earth emitting infrared radiation, related to earth's temperature Particular wavelengths of infrared radiation cause particular gases to vibrate, such that they absorb the IR radiation
What do greenhouse gases do?
Knowledge of terrain (various flora and fauna) Better access to resources Diet Food gathering/producing practices Reliance on farming crops vs pastoralism Records/monitoring/awareness of climate patterns Ability to forecast conditions (so you can plan ahead) Belief systems Trade options with other regions/peoples Technological advances (GMOs, vertical farming, advanced irrigation systems) Public sentiment, politics Transportation, energy consumption/use Intensity and duration of the climate change itself to your region
What does the ability of a society to adapt to climate change depend on
CO2 concentrations and temperatures are correlated and it seems that when one goes up the other follows
What does the long-term variation of temperature and CO2 in air bubbles preserved in the Vostok ice core tell us
Earth's average temperature as a whole is about -18 degrees C Earth's average surface temperature is about 15 degrees C
What is Earth's average temperature?
Clothing choices, technological innovations (e.g. genetic seeds), having trade options w/other regions, people have evolved to live in harsh climates (e.g. low oxygen levels), crop selection (growing certain crops in specific climates), etc.
What modern adaptations do we have that can or have helped us survive or adapt to climate challenges in high mountains, tropical rainforests, or barren, cold high latitudes
Detailed analysis of ice cores and measurements shows: CO2, CH4, N2O changed slowly after the end of the last Ice Age, but began to increase rapidly about 200 years ago
When did CO2 and other GHG begin to increase?
Milankovitch cycles (systematic changes in earth distance and angle relative to the sun) Climate results from a balance between the rate at which energy arrives at and leaves Earth
Why do times of glaciation occur episodically on earth
short-term flows of carbon from seasonal cycles in CO2 (resulting from photosynthesis and respiration) cannot explain the upward trend The trend has to result from carbon that has been stored for long periods of time, such as in fossil fuels and soils
Why do we think that CO2 released by human activities is causing the increase in the atmosphere?
Climate changes naturally on a range of timescales, from decadal, centennial, millennial, and longer (glacial cycles, e.g. Ice Ages) and on a range of spatial scales, from local and regional to global
Why is studying climate change a scientific challenge
Because of the greenhouse effect
Why is the surface so much warmer than the Earth as a whole?
determines the type and location of human-managed ecosystems, such as agricultural farmlands affects the weathering of rock, the type of soil that forms, and the rate of soil formation helps to determine the quantity and quality of water available for human use determines the severity of droughts, storms, and floods largely determines the nature and locations of biomes (major terrestrial ecosystems, defined based on their plant communities) e.g. a prediction of climate change for BC Increase in mean annual temperature across the province for the next several decades
Why should we be interested in climate change?
A vital part of the Antarctic food web A true Antarctic seabird, lifestyle closely linked with environmental changes and sea ice Scientists study the factors that influence the population size of the species
Why the Adelie Penguin