Climate Change Unit 3 (Ch 6-9)
explain the changes in severe weather and why that is bad for humans
(basically everything that I put for why we should care abt climate change, how temp and precipitation are changing, and how sea level and ocean is changing) Severe weather events can affect human health. They can also increase the potential for hazardous chemicals and waterborne and vector borne pathogens to spread through communities and the environment due to facility damage, storm surge, and flooding. (as well as extreme heatwaves which can kill a lot of people mostly children, elderly, mentally ill, the poor, and people in urban areas)
how is climate change going to alter disease and famine
- Malaria, diarrhea, malnutrition, and flooding Climate change can mean more disease: - For example - ebola in west Africa - Abundance of fruit has coincided with outbreaks - Bats and apes gather to eat fruit allowing for zoonosis (zoonosis: illness is not specific to just one animal, disease passed from one species to another) - People encounter these animals, then with each other - Food shortages lead to pressure to eat bushmeat Deadliest animal: mosquitoes (killed 725,000 people per year) Mosquitoes live in wet areas however, when seasons change, they typically die and temporarily the disease dies with them and then once they come back the disease also come back. But because of our changing climate and warming (so because wetter areas will get wetter) they will stay year-round and thus, disease will also stay around year round. They follow warmer weather.
how do we know the CGCM is accurate?
- We can test models by using past data to see if it can be replicated - For example, a CGCM was used to model past surface temperatures of the earth and the model results were compared to observations. - Both natural and anthropogenic forcings were needed to simulate past climate records
what are two main functions of climate modeling?
1. test our understanding of the climate system - start by trying to replicate observational data from the past (if we have something that we recorded (past data), compare our model, then predict future change using data and change.) - if this is successful, then we can have confidence in our understanding of climate and our ability to predict the future. 2. predict the consequences of future climate change - use current data and assumptions about future actions to predict climate's future response.
match the term with the correct definition:
C. Climate lag - caused by the slow warming of the deep ocean and the melting of ice sheets. D. Commitment - the climate will continue to warm even if we stop all greenhouse gas emissions because of this. A. Climate sensitivity - the amount of change expected to happen to balance Ein and Eout to return to thermal equilibrium. B. radiative forcing - greenhouse gases cause a warming effect while aerosols cause a cooling effect for this.
The _________ is the model used to predict future climate.
CGCM (coupled general circulation model)
what is more predictable, weather or climate and why? Explain using CGCM as well.
Climate because it is easier to predict what the climate will be because of the trends we have seen. It is harder to predict weather because we don't know what it could be tomorrow, but climate is easier because we know that due to greenhouse gases and the warming trends we have seen that climate will most likely be increasing in temperature. CGCM could be used to model weather, but smaller grids are needed to model the short and local weather changes. This requires more computational power and precise data that we don't have. Consequently, weather predictions are worse than climate predictions even though the same tools are used. Climate change deniers use weather prediction issue to question climate predictions.
how does the changing climate affect biomes?
Climate change can alter where species live, how they interact, and the timing of biological events, which could fundamentally transform current ecosystems and food webs. Climate change can overwhelm the capacity of ecosystems to mitigate extreme events and disturbance, such as wildfires, floods, and drought. Biomes are dependent on temperature and precipitation, they are moving because of temperature changes.
Explain the difference between commitment, climate sensitivity, and climate lag.
Commitment: we have committed to the warming of our atmosphere due to the amount of greenhouse gases we have put in the atmosphere. The greenhouse gases we have put into the atmosphere have not yet caused all the warming that they will, most of the warming will occur in the coming decades, but some warming will take centuries or millennia due to climate lag. Climate Lag: takes a long time to warm (because of the ocean, delay) delay that can occur in a change of some aspect of climate due to the influence of a factor that is slow acting. Earth's temp is set by the energy into and the energy out of the earth. When these are equal, there is thermal equilibrium and the earth's temp remains constant. Climate sensitivity: (amount of change) tells us how much the temperature of the planet will change to restore the earth's energy balance. There are significant uncertainties in these measurements. (we use calculations using computer models and paleoproxy data using the climate record to look for similar forcings and their associated temperature changes.)
what are ecosystem services and what do they provide us?
Ecosystem goods and services produce the many life-sustaining benefits we receive from nature - clean air and water, fertile soil for crop production, pollination, and flood control. These ecosystem services are important to environmental and human health and well-being, yet they are limited and often taken for granted. Ecosystem services: - Supporting - Provisioning - Regulating - Cultural
what are examples of fast and slow feedbacks?
Fast: immediate to a few years. (ice-albedo, water vapor, clouds, and changes to the carbon cycle that involve the atmosphere.) Slow: thousands of years. (ice sheet contribution to ice-albedo, permafrost, clathrate melt, and chemical weathering.)
what are the differences between forcing and feedbacks?
Forcings: affect climate, but are unaffected by climate (cause of change - 1 thing happening) Feedbacks: (how we respond to change) do not initiate climate change but respond to it - making it better or worse. (respond to change - 2 things happening. 1: initial change and 2: how you respond. Add them together to figure out it it's positive or negative.)
explain climate lag with regards to the radiative forcing and the current warming we have seen
Graphs: to the right of zero: positive forcing, left of zero: negative forcing. (will warm, takes a while because of climate lag, already committed to warming bc of co2 in atmosphere, climate sensitivity is how much we will continue to warm which is .5) We are warming, committed to warming because of co2 in the atmosphere that will be in our atmosphere for a long time. We have not reached thermal equilibrium (our ein and eout).
what does I=PAT stand for? what is increasing? what is decreasing? what are the two components of T?
I - PAT is the simple equation to model climate I: total greenhouse gas emissions (impact on the environment, greenhouse gases) P: are a function of population (population) A: affluence (GDP/gross domestic product, what is your spending, buying more things, how many good someone Is purchasing is also increasing) T: technology (energy intensity and carbon intensity, how much energy are you using, what type pf economic activity are you doing.) I, P, and A is all increasing. Both population and affluence are growing (increasing). T is decreasing. Technology is improving, so its overall effect is decreasing.
why is a rising temperature and changes in precipitation bad for humans?
Increasing heat causes stress to human population. (the most vulnerable is elderly, mentally ill, children, the poor, and people in urban areas) Increasing heat = stress to human population - Significant issue for livestock and crops - Affects transportation and power distribution Changes in precipitation = stress - Shift in water resources and fresh water shortages - In the western US, the fresh water supply is based on snow melt. This will have to change is there's a smaller snowpack each year. - Water shortages will stress the human population Flooding and droughts: - Combined with sea level rise, the risk of flooding in densely populated regions will increase significantly - Droughts will reduce crop yields and increase the risk of fires and dust storms
what are tipping points?
It gets so bad that you can't reverse it. The melting of ice in Siberia, since we push the warming so much it's going to keep warming and nothing we do is going to stop it. The ecosystem gets altered. Point of no return. The climate will worsen, can't fix it.
what data is included in the CGCM
Main answer: anthropogenic and natural forcings. Atmospheric models calculate winds, heat transfer, radiation, relative humidity, and surface hydrology within each grid and evaluate interactions with neighboring points. Past surface temperatures of the earth and the model results were compared to observations. Slide 18 of Ch. 8 notes: A. Simulations done with only natural forcings: solar variations and volcanic activity. B. simulations done with anthropogenic forcings: greenhouse gases and sulfate aerosols. C. simulations done with both natural and anthropogenic forcings (IPCC).
who is causing climate change? who is affected by climate change? are these the same? why or why not?
Mostly human activities are causing climate change. Examples of what humans do are burning fossil fuels, deforestation, cement, agriculture, etc. And this affects literally everything (humans, animals, ecosystems, etc.) (basically everything I put for why we should care abt climate change, how temp and precipitation are changing, and how sea level and ocean are changing.) First world countries are causing climate change and those who will be affected are those in third world countries.
explain how the ocean impacts will affect ecosystems and humans
Ocean impacts: oceans are important for climate stabilization, biodiversity, the food chain, and oxygen. - Due to their size, all life of earth affected by oceans - Ocean changes radically alter many ecosystems at the land-ocean boundary - Climate change is a triple threat for the ocean. Burning fossil fuels, deforestation, and industrial agriculture release carbon dioxide and other heat-trapping gases into our atmosphere, causing our planet to warm. The ocean has buffered us from the worst impacts of climate change by absorbing more than 90 percent of this excess heat and about 25 percent of the co2 but at the cost of causing significant harm to marine ecosystems. - The more co2 the ocean absorbs the warmer it gets and less oxygen and more acidic is gets. - Sea level rise is accelerating, flooding coastal communities, and drowning wetland habitats. - Bleaching: warm-water coral reefs (marine biodiversity hotspots) could be lost if the planet warms by 2 degrees Celsius (3.6 degrees Fahrenheit) - Toxic algae: larger and more frequent blooms are making fish, birds, marine mammals, and people sick - Habitats: lower oxygen levels are suffocating some marine animals and shrinking their habitats - Acidification: more acidic water harms animals that build shells, such as corals, clams, and oysters - Fisheries: disruptions in fisheries affect the marine food web, local livelihoods, and global food security. Oxygen levels are decreasing: - While the oxygen in seawater is only 0.6% of what the atmosphere contains, it is essential for all higher forms of marine life - Organisms continuously consumes oxygen essentially everywhere in the ocean - There has been an average 2% decline in oxygen levels since 1960 because warmer water decreases oxygen solubility Cold water can absorb any gas - they absorb co2. The warmer the ocean gets, the less co2 it absorbs and this will affect sea life because animals in the sea depend on broken down oxygen to survive.
what is on the test
On test: - Climate sensitivity, commitment, and climate lag (know difference) - Slow and fast feedbacks - +/- feedbacks and +/- forcing (know difference between forcings and feedbacks) 6 scenarios on test - Climate models, CGCM and I-PAT > EI + CI (components of T and know what CGCM stands for) - Climate change effects (ecosystems and humans) - Ecosystem services - RCP (know what is stands for) and the 4 different numbers (don't need to know numbers just least to greatest and business as usual) - Difference between daytime and nighttime warming (and which one is warming more) - Where is warming happening globally and why
how can feedbacks be both positive and negative?
Positive feedback occurs to increase the change or output: the result of a reaction is amplified to make it occur more quickly. Negative feedback occurs to reduce the change or output: the result of a reaction is reduced to bring the system back to a stable state. forcings - one thing happening feedbacks - two things happening
what are the differences between positive and negative feedbacks?
Positive feedback: reinforces the change, makes it worse. Negative feedback: counteracts the change, balancing: good. Positive feedback: makes it worse increase + increase = increase Decrease + decrease = positive + + = + - - = + (reinforces the change/makes it worse) Negative feedback: fixes the problem positive + negative = cancel Negative + positive = cancel Positive + negative = negative - Negative + positive = negative - (counteracts the change/balancing: good)
what does RCP stand for and what are the 4 RCP's and why are there 4?
RCP: representative concentration pathway Range from better to worse: 2.6, 4.5, 6.0, and 8.5 2/m^2 2.6 is best case if we stop all emissions 4.5 is if we do a lot 6.0 we do some 8.5 business as usual (no change, we don't do anything)
what does RCP stand for?
Representative Concentration Pathway
why are there so many different projection scenarios?
Scientists build scenarios with a set of educated guesses. Most models list results with a variety of scenarios to provide a range of outcomes. This leads to uncertainties and ranges around predictions. Humans are unpredictable. Global warming projections: - Longer term, there is more spread as uncertainties accumulate - Keep in mind - even a 3 degree Celsius increase in global temperature is not going to be evenly distributed throughout the globe. - And the temperature increases are not the only impact of climate, as climate is many things Warming is happening more in (right now earth is not warmed equally more places warm than others) ex: arctic has warmed more than here and the equator. Northern hemisphere is warmer because of more land. How far away you are from the equator plays a factor of how much warmer you are.
explain how the sea level and the ocean is changing.
Sea levels are rising due to human-caused global warming. Because the climate is warming this causes a lot of glaciers and ice sheets to melt which causes sea levels to rise and because it's not salt water but fresh water, ocean salinity is decreasing. As well as melting ice sheets and glaciers, another factor related to global warming is causing the ocean levels to rise and that's the expansion of seawater as it warms. - Surface temperatures will increase, but more slowly than air due to the high specific heat of water - The deep sea temperatures will rise very slowly - Melting land ice and snow adds water to the oceans - Increased temperatures will expand the water - Oceans are acidifying: as oceans absorb more co2, ocean pH will decrease Sea level rise: - Lots of people live by the oceans so changes to oceans can change where people live, grow food, and have access to fresh water - Effects of storm surges - Increasing soil salinity affecting crops - Loss of farmland, homes, infrastructure
how does the couple general circulation model (CGCM) work?
The couple general circulation model (CGCM) is the cutting edge in climate modeling. It is used to predict future climate. To "run a model, scientists divide the planet into a 3-D grid (horizontal and vertical, every grid interacts with neighbor grid), apply the basic equations, and evaluate the results. Atmospheric models calculate winds, heat transfer, radiation, relative humidity, and surface hydrology within each grid and evaluate interactions with neighboring points.
what is the goal of the IPCC by the end of the century? do you think we will achieve the goal?
The goal of the IPCC is to keep warming below 2 degrees Celsius compared to pre-industrial averages. The longer we wait to reduce emissions, the harder it will be to keep warming below 2 degrees Celsius. I think that if we stop emissions now (which is not likely) we could meet this goal. However, that is wishful thinking. There is no way we would stop all emissions now so unfortunately; I don't think we will meet this goal which is very heartbreaking to admit. - If we had started in 2000 (reducing emissions) 2%/year reductions needed - Start in 2020 - 6%/year reductions needed - Start in 2030 - 10%/year reductions needed
what is a radiative forcing?
The measure of how much a given heating or cooling effect changes the energy flow into the earth. Positive forcing: warms the planet (co2, other greenhouse gases) Negative forcing: cools the planet (aerosols and precursors, these have many negative health impacts. Cleaning them up will increase warming.) 1. greenhouse gases + 2. aerosols - 3. land-use changes - 4. changes to the sun + Total net forcing: + (means that the planetary average temperatures are going up)
explain how the temperature and precipitation is changing.
The temperature is getting warmer, which means more hot days: - record setting will be the norm, and heat waves will be more frequent. - hotter nights: warm nights as the atmosphere retains more heat. - Nighttime low temperatures will rise more than daytime highs. - Land will heat more quickly than water, and therefore northern hemisphere will heat more - Poles will heat more than tropics due to ice-albedo - Impacts of heat will be varied and affect many aspects of our lives Precipitation: wetter in many areas (not always a good thing) A super charged water cycle: - A warmer atmosphere and ocean accelerate evaporation - More precipitation and potentially severe precipitation events (wetter areas will get wetter, dry areas will get drier: more rain & less snow, more intense but irregular precipitation, and high chance of both floods and drought) Changes to temperature and precipitation (climate) may lead to changes in communities. (more Ein)
why do we care about climate change? what will it affect?
We care about climate change because this is our planet and at the rate that it's warming is alarming. We will see animals, plants, ecosystems, and humans suffer because of this. Humans can adapt the best due to air conditioning, however, humans in low-income areas that don't have AC units will suffer just as much as animals who also don't have ways to cool off in the warmer temperatures. This is all due to human activity and deforestation and other things also disrupt ecosystems and food chains. Animals will have to migrate, and this will disrupt food chains and ecosystems. Etc. This is just the few ways climate change and global warming will affect everyone. It has affected: - Where we plant crops - Where we build homes and other infrastructure - What kinds of food is available to us - Where we set up preserves and parks The magnitude and rate of climate change will be challenging even to the most adaptable species. Several major impacts of climate change: physical impacts - Temperature - Precipitation - Sea level rise - Ocean acidification - Loss of ice According to EPA: main risks - Changes in the timing of seasonal life cycle events - Range shifts - Food web disruptions - Buffer and threshold effects - Pathogens, parasites, and disease - Extinction risks
the highest RCP is our worst case scenario. what do we also call it?
business as usual
which of the following always warms the planet? (positive forcing/feedback loop or negative forcing/feedback loop?)
positive forcing
In I=PAT, which is the ONLY variable that is decreasing?
technology (T)
consider this argument: "we cannot predict the weather in a week, so there is no way we can believe a climate forecast in 100 years." Is this argument right or wrong and why?
wrong because it is easier to predict large scale climate averages than it is to predict daily local variations.
