pre-work exam 1
The greenhouse effect works with greenhouse gases such as water vapor or carbon dioxide. Carbon dioxide molecule traps energy and it's molecules become quantized. The energy is then passed and the atmosphere around the molecule is warmed (most time equally in all directions) which then warms the atmosphere. From just carbon dioxide, the Earth's surface will warm about 2 degrees Fahrenheit if everything else is constant.
7Explain how the Greenhouse effect works, specifying how much a doubling of CO2 warms earth on its own
Being able to slow the rate of global warming allows ecosystems to not perish quickly, but it also allows a greater opportunity for humans to adapt to changes. Sea level rise, for example, is predicted to be 0.1 meter lower with warming of 1.5C rather than 2C, which gives humans and ecological systems of small island, low lying coastal areas, and deltas more time for adaptation. On land, by staying around 1.5C rather than 2C decreases rates of species loss and extinction which maintains the global biodiversity. Additionally, there is expected to be a transformation of ecosystems from one type to another within global terrestrial land, and risk of this is 50% lower at 1.5C than 2C. Lastly, ocean temperature increase, associated increases in ocean acidification, and decreases in ocean oxygen levels, all decrease in risk by limiting warming to 1.5C instead of 2C.
Compare the effects of 1.5C and 2C warming. Identify tipping points or feedbacks.
Fossil fuels as we see them today are not what they were seen as by our ancestors. Initially, Cape Cod inhabitants found use of fossil fuels as a way to allow reforestation in their surrounding areas. Additionally, a whale moratorium was able to be placed on commercial whaling due to the alternative of fossil fuels.
Describe the effects of the discovery of oil on other energy sources.
Climate change will be affecting many communities; we are experiencing intense weather events occurring more frequently. These changes will cause destruction of infrastructure, ecosystems, and our health. Infrastructure will be destroyed through the sea level rise; our coastal regions will not be able to handle the water unless new structures are built to keep it out. Animals ecosystems are already changing; the shifting weather has caused certain animals to migrate to where they have never been before. The rise in sea level will destroy many of their homes, and this will all change our food supply drastically. If animals migrate to new areas the old place will not have the food that they need, and the drastic changes in weather will make it hard for us to grow new crops. These changes in our temperatures also have a massive impact on our health; more wildfires will impact our air quality negatively. We can expect more diseases in our food and water as well.
Detail direct effects on human beings that climate will have on the US. Draw on at least three areas of the report in formulating your response.
The total use of fossil fuels per person in the United States is about 175 pounds each year. According to the book, we are responsible for burning about 100 times our own weight in fossil fuels and putting out more than 250 times their body weight in carbon dioxide. We are putting more carbon dioxide into the air than we are putting our trash into landfills every year.
Explain US use of fossil fuels per person, including quantities.
There has been an observed warming in the upper 6,560 feet of the ocean since the 1960s in which the surface ocean has increased in temperature by about 1.3ºF. Additional to warming over the last 50 years there has been recorded decreases in oxygen levels within inland seas, estuaries, and coastal seas nearshore. Both of these examples relate directly to key message 3 of Our Changing Climate, which states oceans have absorbed 93% of the excess human-induced heat, and that these increases in temperature combined with other climate patterns are resulting in a decrease in oxygen for marine life.
Explain how 2 examples given in the chapter on Our Changing Climate relate to a single key message
CO2 increase is from fossil fuel burning because we know that burning oil, coal, and natural gases produced a lot of CO2. We know that the amount of CO2 in the air is not from volcanoes or the ocean so the majority of it has to come from human production. Another reason is by checking the bookkeeping and seeing that there are numerous CO2 sources, such as cosmic rays and plants, but CO2 levels have raised mostly after the Industrial Revolution.
Explain the ways we know that the CO2 increase is from fossil fuel burning.
We know this mainly by looking at the current quantity of anthropogenic carbon dioxide emissions and comparing them to the past. We also know this because the ocean temperature is rising and so are sea levels. A lot of heat is being stored in the ocean right now that would instead be in our atmosphere, and is expected to be in the future. Until then, the heat will slowly be distributed throughout the ocean and the sea level will continue to rise for centuries to come.
How do we know that changes in the ocean are due to anthropogenic carbon dioxide emissions?
Past sea levels in the Pliocene and Last Interglacial event indicate that the Antarctic ice sheet is considerably sensitive to warming depending on the level of CO₂ in the atmosphere. During the warm climate interval in the Pliocene roughly 3 million years ago, the sea level was 10-30m higher than today's sea level, and during the Last Interglacial event 130-115 thousand years ago, the seal level was 6-9.3m higher than the current sea level.
How high was sea level in the past, and why?
The thing that most surprised me about the solutions they presented was the fact that most of the solutions related to the management of our resources, whether it be food or land. Out of the top 20 problems, 12 of them were related to management. And the fact that the biggest problems of refrigerators weren't that they just hog electricity but that their chemicals were the biggest problem. Another thing that I thought was interesting was how some methods of environmentally friendly farming have already existed for years and years and our "farming culture" chooses to use harmful methods of farming.
In the drawdown video, what surprises you about the solutions they propose?
The first two key messages in this chapter of the 4th National Climate Assessment revolve around the warming that has already been observed as well as the warming still expected to occur. Understanding that the global average temperature has increased around 1.8ºF since 1901, and is expected to increase by a total of 3.6ºF in the future. A key aspect of these messages is the observed and expected warming are all pointing at human activities as their cause, and without any major changes in the way society lives in their environment, increases in temperature could reach up to 9ºF which would be catastrophic.
Summarize 2 of the key messages from Our Changing Climate
Key message 2 describes how risks are multi sector and should be assessed with the understanding that there are several sectors involved in climate change. By doing so, we not only are able to involve evidence from several aspects, but we are also able to consider several possible outcomes to prepare for. Additionally, key message 3 describes the multi sector approach to dealing with climate related stressors impacting communities. The integration of several systems when dealing with these stressors can help a community be more resilient. Therefore, these two messages are stating that when understanding climate change there are several sources, but also when climate stressors are impactful there are several sectors involved in solving the problems.
Summarize 2 of the key messages from your National Topic.
With the rise in sea-level, we can expect for there to be more construction of ways to protect low-lying areas. We can also expect more contaminated water, our food supply will be in danger, and wild-life habitats to be destroyed. Economists are not actively working to prepare for the changes in the economy from the sea-level rise because they assume that we will act accordingly when the time comes.
What are some impacts of sea level rise, and why is the economic assessment of the damages likely to be flawed?
The three criteria that decide which impacts the irreversibility study examines are: 1) Observed changes that are already occurring, for which there is evidence of anthropogenic contributions to said changes; 2) the phenomenon in question is one based on well-understood physical principles; and 3) the projections in question are available strong ("robust") across various models.
What are the 3 criteria that decide which impacts the irreversibility study examines? Describe the policy implications of the study.
Economic effects include reduction of energy production methods, as well as a decrease in revenue from related areas such as tourism and the fishing industry. Infrastructure wise, power outages will be more common and longer lasting. The trillion dollar costal property market that exists in America will also be threatened. Heavy flooding will be an issue, too. The prices of importing and exporting will also increase. Another issue has to do with transportation. Heavy rain, flooding, excessive heat, wildfires, and more impact the effectiveness of transportation. Coastal roads and bridges will be threatened as sea levels rise.
What are the economic and infrastructural effects of climate change in the US? Explain one in detail
Pennsylvania became a desert because people were using tress at a faster than they could grow, they had to cut down anywhere from 300 to 400 acres to build one furnace alone, forge iron alone was responsible for the loss of 640 acres of forest in one year. This caused Pennsylvania to have vast stretches of land where the trees were simply gone. Along with that, the majority of the Pennsylvania fauna was lost which made people have to resort to importing livestock
Why did Pennsylvania become a "desert"? Explain, specifying key quantities.
With all of the effects of climate change it is not very surprising that some regions have already surpassed the global mean temperature. Some areas are experiencing more droughts. Temperatures are also going to the extreme leaving very hot days, that are expected to increase in frequency.
Why have some regions surpassed the global mean temperature already?
Photosynthesis occurs by means of the following equation: 6CO2 + 6H2O + Light Energy C6H12O6 + 6CO2. and Cellular respiration occurs through the reaction of: C6H12O6 + 6CO2 6CO2 + 6H2O + Energy. It is important to remember that while written, these reactions look like the reverse of each other; however, in nature there are several different steps that occur through the two processes that vary from each other.
Write the formula for photosynthesis and respiration.
The process begins by acquiring Timber and cutting it into four-foot wood, this is done to help the process of conversion easier. Then around thirty cords of wood are stacked into a pile that is 15 feet tall and 30 feet wide, this pile was then covered by dirt and sod with a central vent and holes that were strategically placed on the pile. The wood would then be set ablaze and it would burn underneath the dirt and sod for around 2 weeks after most of the original wood was lost, the holes in the dirt cover were completely shut and as the fire slowly went out, the charcoal was separated and carried to a furnace by mule.
explain in detail how charcoal is made
They frame their discussion of climate change by emphasizing that the problem is not climate change itself, in fact, climate change is just the expression of the real problem which is global warming, which is caused by human activity. They talk about how the problem is that we as a whole don't properly manage our resources and that there are more solutions than just stopping the usage of fossil fuels.
in the drawdown video, How do they frame their discussion of climate change?
Climate sensitivity is the warming from doubling CO2 which is about 3oC. Scientists usually calculate this at a lower value sticking between 2-4.5oC because of the lack of knowledge on clouds. There are too many uncertainties to fully estimate the positive feedbacks so their estimates lie on the more generous side.
Define climate sensitivity, and explain why scientists are more likely to calculate a lower sensitivity than a higher one. Provide quantities.
Negative feedback is a reaction/response that reduces the initial change. Positive feedback is a reaction/response that amplifies the initial change without tipping. Tipping is when positive feedback crosses a threshold, meaning the change reaches a "tipping point
Define positive feedback, negative feedback, and tipping points
In order to understand precession, Alley says to imagine spinning a top. As the top is spinning the red handle sticking out of the top is creating its own smaller circle, this is the precession. As the top begins to slow the precession will get bigger, and the angle between the north pole and its vertical is the tilt. Since the Earth's orbit is not circular, it makes our distance from the sun change every year; the eccentricity shows us how noncircular the orbit is. According to Alley, "Eccentricity controls how much effect the precession has on summer sunshine." Right now the Earth is approaching its furthest distance from the sun during the northern summer, but 10,000 years ago the opposite was true. This has caused midsummer sunshine to drop in the North and increase in the South over the last 10,000 years.
Define precession, eccentricity and tilt. What effects do they have on climate? Include relevant numbers.
"Committed warming" refers to the idea that even if there is no increase in greenhouse gas levels in the atmosphere, we will still see an increase in global temperatures in the future. This is because some of the CO2 warmed air goes into the ocean, so the atmosphere has not gone through the full heating of the CO2. Projections include a range because of model uncertainty and internal variability. Warming projected to be on the warm side of the range because the IPCC estimates are all pointing in the low end of the uncertainty ranges. This means that warming will most likely be on the high side of the best estimate
Define the term "committed warming." Explain the two reasons projections include a range of probability, and why warming is more likely to be on the high side of the probability range.
The climate impacts on water will include very heavy precipitation in some areas and droughts in others. In these areas that will receive precipitation, not only will it be heavier, but also more often. This combined with the rising sea level puts many of our cities at risk. Coastal cities are prone to being completely flooded unless we build infrastructure to protect it. We can also expect more flooding and damaged buildings
Describe and explain the relationship between climate impacts on 2 of the following: health, food, water, security. For example, how are water impacts related to security?
The sun always has a big effect on the climate. Although its sunspot cycle not not changed much, in the early 20th century the sun brightened a little bit; this had a heating effect of 0.12 W/m^2. The eruption of Mt. Pinatubo also had an effect, but this one was cooling. After the eruption the peak of the cooling effect reached 3 W/m^2.
Describe and quantify natural effects on climate.
Although greenhouse gasses are responsible for much of the change in climate there are still other human factors that affect it. The way that we live has caused a shift in how much energy is reflected by clouds and by the Earth's surface. We have already tried to replace dark forests with more reflective crops this has a major cooling effect, and cools the Earth at about 0.2 W/m^2. The only issue is that this cooling is competing with the effects of the wildfires; this is because the soot from these fires tends to blacken the reflective snow and gives a warming of about 0.1 W/m^2. A big contributor is also acid rain, sulfuric-acid from coal plants creates particles in the air these particles actually block sunlight and have a cooling effect of 0.5 W/m^2. Jet contrails have a small heating factor of about 0.1 W/m^2.
Describe and quantify the non-GHG human effects on climate
After the meteorite came and eradicated dinosaurs the climate stayed warm with high levels of CO2. Then something weird happened, and the climate kept becoming warmer. The ocean became more acidic causing many bottom-dwelling species to go extinct, many species began to migrate or diversify, and insect damage to land-plant leaves increased. After this hit its highest point, the Earth began to reverse back to normal. This event was caused by the high levels of CO2, but it is difficult to figure out exactly how all of that CO2 got released into the atmosphere. There are some suspicions that it was caused by sea-floor methane clathrate, volcanoes intruding organic-rich rocks to get rid of their carbon, the burning of lots of plants, or drying of a seaway to expose the organic-rich sediments to oxygen, but we still do not know the exact cause of the PETM.
Describe the Paleocene-Eocene Thermal Maximum and its likely causes.
Due to a significant evolution of multicellular life in the oceans, photosynthetic land organisms released oxygen before there was enough aerobic life to receive it and release CO₂ back into the atmosphere, causing Earth's climate to remain cold. Between 250 million and 65 million years ago, though, there was enough land organisms to receive oxygen and release carbon dioxide; Pangaea started to break up, allowing more land to come into contact with oceans, creating humidity which contributed to a warmer climate. This climate was roughly 10 °C higher than today's climate and the global temperature was mostly uniform. Then, most scientists theorize that around 65 million years ago a 200 kilometer wide asteroid hit what is now called Mexico, driving a lot of flaming rock into Earth's atmosphere, which likely led to an "impact winter" cold enough to kill the dinosaurs and thus allow mammals to thrive.
Describe the climate and the role of plants during the Cambrian explosion.
Currently the amount of carbon dioxide in the air is at about 400 parts per million, and it is not stopping anytime soon. By the year 2100, scientists are expecting the carbon dioxide levels to hit 1,000ppm. At this point, human's cognitive ability decreases by 21%. Increases in pollution are capable of shortening our lifespan by 10 years. By the middle of the century Americans will most likely experience a 70% increase in unhealthy ozone smog. It is projected that by 2090 only 2 billion people will be breathing in air above the WHO "safe" level. Fossil fuel burning and wildfires will also have a major impact on these numbers and our air quality
Describe the impacts of air chemistry and particulate, using relevant quantities and examples.
The use of analysis of sediment condition, location, and properties are important, as is the age of said sediment, looking at shells, and looking at plant walls. For example, some algae use "alkenones" in their cell walls, and use this to either make their cell walls more flexible (with single carbon bonds) or less flexible (double carbon bonds). When the water in colder, the cells become more unforgiving, so the plants adapt to make single bond walls for increased flexibility. By digging up these cell wall structures that can be found in mud, we can determine the climate at a certain time.
Describe the main indicators or proxies of past climate. Explain one in detail.
There are many tests that scientists have to make sure that they are accurately measuring temperatures. There are things that need to be adjusted whenever it comes to measuring climate based on where you are located. Cities bring extra heat, so setting up a weather station right there would skew the data and whenever measuring global climate many scientists scrap the data they receive from city temperatures. It is also important for researchers to make sure there is no bias. Testing to see if at night there is a lot of wind or not can help them to see if a company is giving them numbers that are inaccurate.
Describe the methods we have for measuring temperature.
Conduction is when you actually have to make contact with something to give off heat, while convection gives off heat through a medium, like a flame. Radiation is the transfer of heat without making contact. For example, a planet (earth) can't lose or gain enough heat through convection or conduction, so in that case you need radiation to control the temperature.
Distinguish between conduction, convection, and radiation.
No, ocean acidification does not mean the ocean is becoming more acidic. Seawater itself is basic, so the acidification is shifting it to become more neutral not acidic.
Does ocean acidification mean that the ocean is becoming acidic? Why or why not?
The economic and infrastructural effects of climate change actually tie together. The change in climate will affect our infrastructure because we are expecting a rising sea level. If the sea level rises much of our coastal infrastructure will be destroyed. With the infrastructure destroyed, this will have a major impact on the economy of the coastal region because if their infrastructure is destroyed then all of the business there is destroyed. The economy is also being affected by the migration of animals; if the animals are moving that they typically catch to eat, then all of their business is gone. The increasing temperatures will also have a direct impact on the productivity of workers; if you are hot, you are more tired and less able.
Drawing on two areas of the report, what other problems (natural and human) does climate change intensify? Explain one of these in detail
In the far past CO2 levels rose after an increase in the temperature. This was because the increase of temperature caused feedbacks, one of which was a rise in CO2. This increase in CO2 then became in control and started to increase the temperature even more.
Explain how CO2 can cause warming, even if it follows temperature changes caused by other factors.
Warmer air can carry more water vapor, so a warmer atmosphere will cause more frequent and heavier precipitation. However, dry areas are expected to experience a drought. So we can expect for dry areas to keep getting more dry and wet areas to keep getting more wet. Areas in the middle of these regions might experience a switch from wet to dry because of how the climate is shifting toward their area.
Explain how global warming affects precipitation and storms.
When scientists create models, the are using averages of several different factors such as temperature or location of grasslands and cities, and they set parameters within a range. Through several factors within the scenario, scientists create a model representing a climate looking very much like the Earth's and they check against history to evaluate the accuracy of their projections from years or decades ago in order to gain confidence in future projections. The four ways the models are assessed before being brought forward include: results must be understood from fundamental science, results appear in a range of models, results appear in varying data from different research groups, and results appear in recent data from various research groups.
Explain how scientists use models to "predict" past temperatures. Why is this a valuable scientific activity? Explain in your own words the 4 ways model results are assessed.
Water: About 80% of the world's population already suffers from serious threats to its water security, that is if we take availability, water demand, and pollution into consideration. Freshwater stress is expected to occur as a result of projected aridity change. Furthermore, warming of 1.5°C might increase the risks for water availability. Health: Any increase in global temperature is expected to affect human health. Urban heat islands will the impacts of heatwaves in cities and risks for some air-borne diseases, such as malaria and dengue fever are projected to increase with warming. Food: Risks of decreasing food security are expected to become greater as global warming reaches 1.5°C and both ocean warming and acidification increase, with substantial losses likely for coastal livelihoods and industries. High levels of adaptation will be required to prevent further impacts on food security.
Explain impacts on health, food, water, and security
Risks related to health, food, and water are expected to increase as the Earth warms to 1.5 and will increase further with 2ºC. Communities dependent on agriculture/coastal livelihoods, dryland regions, small islands, and lesser developed countries are all at increasingly high risks surrounding health/food/water. In general, as heat increases, so do human's health risks. This includes general access to food and water, which will greatly impact people globally.
Explain impacts on health, food, water, and security by reading a relevant part of the full report
Obviously the sun has a major role in heating our atmosphere, but it is not as big of an effect as burning fossil fuels. The sun changes extremely slowly, so in the past over time it has been a reason for climate change, but the climate is changing so fast right now that the sun does not have much of an effect on it. This is why we do not see much about the sun raising the global temperature maybe a couple tenths of a degree.
Explain one possible driver of climate in detail, along with why it does not explain current warming
The main controversy lies in if it is ethical to explain the worst case scenario in a journal article. It is worth it to get everyone this worked up about a situation that is not extremely likely to occur. Scientific reticence is the way that scientists sometimes speak that makes a situation seem less dire than it actually is. It minimizes the problems discussed because people are not getting the urgency from the language used. This article frames climate change as a very serious and pressing issue. It is framed this way because the author knows that it is a vital topic and that is it excessively important and should be treated as such.
Explain the controversy over the article "Uninhabitable Earth." What is "scientific reticence"? How does the article frame climate risks, and what reasons does the author give for framing it in this way?
Representative Concentration Pathways (RCPs) are different scenarios the IPCC describes in order to project varying trajectories for CO2 emissions. RCP 2.6 is considered the best case scenario as far as limiting anthropogenic climate change; however, it would require a turnaround in climate policies and actions from both developed and developing countries. RCP 4.5 is characterized by emissions peaking mid-century, about 50% higher than 2000 levels, but then decrease over the span of 30 years to level out at about half of the 2000 levels. RCP 6 is a scenario where CO2 concentrations continue to rise, emissions double by 2060 to then fall and concentrations are slower to rise but we still remain well above the current levels. Lastly, RCP 8.5 is the worst case scenario, where emissions continue to increase rapidly, to a point where around 2100 emissions stabilize at 30 gigatonnes of carbon as compared to 8 gigatonnes in 2000.
Explain the different IPCC Representative Concentration Pathways (RCPs).
The RCPs are used for making projections based on socio-economic factors -- such as population size, economic activity, lifestyle, energy use, land use patterns and technology -- and describe different 21st-century pathways of GHG emissions. The four scenarios are stringent mitigation (RCP2.6), intermediate GHG emissions scenarios (RCP4.5 and RCP6.0), and very high GHG emissions (RCP8.5).
Explain the different IPCC Representative Concentration Pathways (RCPs).
A system known as "the Ocean Conveyor" or climate's "Achilles Heel" is the deep circulation system of the oceans that drives the ocean currents. The ocean currents are what distributes heat across the globe and is extremely important when it comes to global climate. However, CO2 emissions are increasing temperatures of the ocean which is changing the typical circulation by slowing it, which creates even further climatic consequences. Additionally, the ecosystems of the ocean are being impacted by warming, coral-reefs are dying and unable to grow at their normal rate, growth of algae is changing, and increasing acidity is dissolving carbonate shells.
Explain the effects of CO2 - driven global warming on oceans.
Roughness in terms of climate modeling means that it is constrained by data. This means that using maps will show a landscape. There is uncertainty in climate modeling because no measurement can be perfect, and if we want it as accurate as possible we need to use averages. Tuning is used in order to approximate current data within narrow windows of real measurements.
Explain the meaning of key terms in climate modeling: roughness, uncertainty, tuning.
Rock weathering is a result from the rate at which the volcanic CO2 and rock come back together at the surface. Warming speeds up these chemical reactions. When there is cold climate, CO2 comes out of volcanoes and into the atmosphere. The extra CO2 warms the planet. But when the climate is warm, CO2 can react with rocks and cool the planet. Since it's a long process for CO2 to emerge from volcanoes, it takes a while for the rock weathering to make a big difference in the planet's temperature.
Explain the mechanism of the rock weathering/CO2 thermostat
If the permafrost melts, this will trigger a massive release of methane into the atmosphere. Methane is 34 times as powerful as carbon dioxide. Also, this permafrost melt will release double to amount of CO2 into the atmosphere than there already is. This all can accelerate warming by a couple degrees. 252 millions years ago the earth warmed by five degrees triggering the release of methane in the Arctic; this wiped out 97% of all life on Earth. Right now, we are going at about ten times faster than that rate, and it keeps accelerating. We can also expect for it to be too hot to go outside.In El Salvador, ⅕ of their population has a kidney disease linked to dehydration.
Explain the problem of permafrost melt. Describe the extinction event connected to permafrost melt. How is this related to the threat of disease?
Global warming is mainly caused by how much carbon dioxide we are releasing into the atmosphere. Most of the carbon emitted ends up being absorbed by the ocean. This then causes the pH in the ocean to lower, making it more acidic.
Explain the relationship between global warming and ocean acidification.
Whale oil was used in lamps and lanterns, it was a bit more expensive to buy but it lit better than other oils, didn't smell much and had little risk of exploding -- which was good considering explosion from other oils were responsible for the deaths of many people, including a 13-year-old girl who was holding a lamp while it exploded. Since the demand for whale oil was so high, people started going off to the sea to participate in whaling, with 10,000 seamen on ships out in the ocean at the peak of the whaling. At the peak of production, there were about 12.5 million gallons of whale oil being produced a year, thankfully that number dropped down to 2.5 million gallons by 1875.
Explain the use and importance of whale oil, including key quantities.
It's estimated climate change has influenced between 3-20% of armed conflict risk and this is only going to increase. Influence on conflicts would increase more than 5 times, causing a 25% increase in conflict risk. The real world factors that will increase this risk are damaged economies, lowered farming/livestock production, and an intensified inequality between social groups.
Explain the ways climate change will increase the likelihood of armed conflict, using examples and quantities.
Instead of their being one policymaker, the Academy brings forth many different views since there is an entire committee of scientists. If there is a single scientist then they are able to say whatever they want, but with a group of scientists there are too many people watching them and what they say for them to say something that is not factual. Also, the Academy is not being paid which eliminates bias from being bribed.
Explain ways the National Academy of Sciences prevents reports from containing bias.
When approaching how to handle the warming of the 20th and 21st centuries, it is important we focus solely on the drivers of climate that are most rapidly creating change and put aside the causes making very little change. The drivers of climate we can put to the side when evaluating the warming are drifting continents and orbits because in the grand scheme of everything, they only make roughly a difference of 0.1ºF per century. It is important to recognize though, that while we are setting these drivers aside for the 20th-21st centuries, they are still important aspects but only in time scales of millions of years.
Explain what drivers of climate are bracketed, and why they are set aside as we explain 20th-21st century warming.
The temperatures of Venus, Mars, and Earth are different because their atmospheres are different thicknesses. Thick atmospheres trap more heat from the sun than thin atmospheres. Alley started by calculating how much sunlight is reaching the top of the planets' atmospheres, subtracted the reflected part, the distribution around the rest of the planet, and figured out the temperature needed to radiate that much energy back into space. For Mars he got -78* F, for Earth he got 0* F, and for Venus, he got -63* F. Mars has a thin atmosphere, so its surface temperature is 11* F warmer than Alley's original calculation. Earth has a thicker atmosphere, so its temperature is warmer than the original calculation by 59* F. Venus has a much thicker atmosphere than Earth, so it's 855* F times Alley's original calculation.
Explain what makes the temperatures of Venus, Mars, and Earth different, using quantities.
Two factors that will cause the sea level rise to be irrevocable are the process by which warming causes the ocean to expand, and thus the sea level to arise; and the loss of land ice which raises the sea level as the atmosphere warms and the land ice continues to melt. There are also studies which imply that changes in winds contribute to the currently observed rapid ice sheet flow that contributes to sea level rise, and a less certain but important observation based on the past (the Paleolithic age) indicates that slow ice sheet mass balance might also contribute to sea level rise. Ice discharge is projected to contribute up to 1-2m of sea level rise, thermal expansion of the ocean could raise sea level from 0.2-0.6m per degree of warming, in addition to the complete loss of glaciers and small ice caps which could raise future sea level by approximately 0.2-0.7m, and even partial loss of the great ice sheets in Antarctica and/or Greenland could add several meters to these quantities of sea level rise in the future.
Explain why sea level rise will be irrevocable: what are the causes, and how much are they likely to cause?
Since our planet is 71% water with a depth of 3.8 km, the oceans play a major role in the climate system. Water holds a very high heat capacity and its ability to hold, store, and transport heat help to majorly cool down our atmosphere.
Explain why the ocean is a primary player in the climate system, using quantities.
10% of cereal crop is lost for every degree of warming. If there is greater warming, then it may be better to grow crops at some places, but even a small increase in temperatures will cause places with the current optimal growing temperature to not be able to produce crops as efficiently. There are already some regions that are too hot to grow certain crops, so a warming will increase this everywhere.
How much cereal crop is lost for every degree of warming? EITHER Explain optimal growing temperature, and the problems with relocating agricultural production to more northern regions, OR explain the problem of drought.
The are four main climate drivers to focus on when looking at the warming of the 20-21st century are as follows: volcanoes, sun, ocean-atmosphere events, and CO2. Aside from CO2, it is important to focus on these drivers because even though in the data of our history they have made a relatively small impact on climate, these variables contain uncertainties that may be twofold or more in terms of impact. CO2 is the biggest climate driver to focus on because once the Industrial Revolution occurred, the CO2 variations skyrocketed to seeing highs of 380 parts per million (ppm) when the usual highs were around 280ppm. Additionally, the evidence from seafloor sediments indicates the current levels of CO2 is the greatest we have seen in about 2 million years.
What climate drivers need to be accounted for in explaining 20-21st century warming, and why?
Abraham Lincoln was in charge of signing the bill to establish the National Academy of Sciences. The act stated that they would "investigate, examine, experiment, and report upon any subject of science or art" anytime the government called upon them; they also would never accept payment. Their mission was to help the US government in whatever science or art assistance they would need without receiving compensation for their actions.
What does the National Academy of Sciences do, and what do they not do?
Peak oil describes the idea that at what point in time will we reach our maximum use of fossil fuels before we run out. Since the rate at which the plant materials needed to burn fossil fuels grows is less than the rate at which we are burning fossil fuels, we will eventually run out. We should only be using about 0.0001 Gt C per year, and we are currently using 6Gt C per year.
What is "peak oil"? Explain, including the concept of net primary production and quantities.
Most likely the cause of snowball Earth was the rising oxygen had probably broken down some of the nonCO2 greenhouse gases.The Earth became very cold with the lack of greenhouse gases and glaciers left deposits extending to sea-level in the tropics. This freezing cold slowed rock weathering which allowed CO2 from volcanoes accumulate. Eventually whenever the warmth overcame the reflectivity of the snow, the snow began to melt.
What likely caused snowball earth? How did earth get out of it?
Geological record shows that that, 10 million years after the Cambrian explosion, sudden warming was caused by a large infusion of carbon in the environment, largely hypothesized to have been due to methane being released by sudden melting of methane-containing ice at both the seafloor and the poles. This could have been due to an underwater volcanic eruption or change in the solar cycles, melting the "methane ice" which led to "greenhouse Earth" during which the planet was completely void of ice.
What likely led to a warmer climate after the Cambrian explosion?
If we begin to act on climate change we will still be able to continue life as (almost) normal. Of course we will have to begin using alternatives to the things that are causing climate change, but these changes are much smaller than the life we will live if we decide to do nothing. If we can begin to slow climate change back to a normal pace our economy will not be damaged, our wildlife will return to normal, we will not have to worry about more natural disasters, we will have cleaner air and water than before, and our infrastructure will not be damaged.
What non-climate benefits are there of acting on climate change?
Likely is above 66%, very likely is above 90%, and extremely likely is over 95%.
What percent probability do "likely" "very likely" and "extremely likely" represent?
Humans have major control over the climate. Our current release of greenhouse gases have caused a major increase in global temperatures. If we put a halt to out CO2 emissions and cut back on other greenhouse gases this would have an impact far into the future. If we stopped using greenhouse gas emissions the highest temperature reached in the future would only go up as high to what our past emissions allow. If we stopped now we could prevent feedbacks from being triggered, minimize sea level rise, and reverse ocean acidification
What sort of control do we have over the climate? Detail the warming human emissions have already caused
We humans have long-term control over climate. The actions we took after the industrial revolution caused us to be responsible for the increase of 1 degree in the global mean surface temperature. Warming from anthropogenic emissions from the pre-industrial period to today will persist for centuries and will continue to cause even more long-term changes in the climate system, such as sea-level rise, with associated impacts. Human emissions have caused approximately 1.0°C of global warming and will increase to 1.5°C between 2030 and 2052 if it continues to increase at the current rate.
What sort of control do we have over the climate? Detail the warming human emissions have already caused
Good generalization must have specific examples, have more than one example, and have representative examples. You must have examples that have actually happened and more than one in order to have a base for your generalization to lay upon. You must also have a representative example that is not an odd, extreme example, but one that can represent your generalization in a way that can prove it to be true.
What three requirements must a reliable generalization meet?
A cause-and-effect inference must cite accurate correlations such as statistics from scientific research in order to provide readers with basic factual evidence. Secondly, the argument has to explain how the potential cause would lead to the potential effect, at which point the previously mentioned citations are examined and explained contextually to create a connection for the reader. The argument must finally explain how the proposed cause-and-effect connection is the best possible explanation at hand to convince the reader it would be a likely relation, proving all other variations of correlation would not be as sensible as the one being argued.
What three requirements must such a cause-and-effect inference meet?
