Climate Change Midterm II

Global temperature and sea level are both above their normal range of the past 2,000 years. True or False?

\-True

\-Proxy records show that current warmth is unprecedented in at least 2,000 years. 

The Atlantic article “The most controversial chart in science explained” acknowledges that the “hockey stick” graph is the main piece of evidence that humans are driving climate change; if climate skeptics disproved the graph, they would disprove human-caused global warming. True or False?

\-False

\-The hockey stick graph is only one of many lines of evidence that humans are the major driver of recent global warming

\-Even if it turned out that today was not the warmest interval of the past 2,000 years, it would still not cast much doubt that humans are causing climate change given all of the other evidence supporting this view

The “hockey stick” graph has been reproduced many times by independent groups of scientists (forming a “hockey team” of temperature curves).  True or False?

\-True

\-The original “hockey stick” temperature graph was published in Nature, 1998

\-The Y-axis shows the Northern hemisphere mean temperature, in degrees Celsius

\-the zero line corresponds to 1902 – 1980 mean

\-Since then, the "hockey stick" graph has been reproduced many times.

What does this represent?

Global temperature over the past 2,000 years

What does this represent?

An altered chart of global temperature over the past 2,000 years circulating online

Which best describes the scientific basis for linking the rise in atmospheric CO2 levels to fossil fuel burning?

Scientists are highly confident about the link based on numerous lines of evidence, including the timing, rates, amounts, and chemistry of the CO2 changes

Which best describes the scientific basis for linking global warming over the past 50 years to rising greenhouse gas levels?

Scientists are highly confident about the link based on numerous lines of evidence, including the spatial pattern of temperature change, climate model simulations, and the amount of warming relative to natural variability

Which is true about the recent rise in atmospheric CO2 concentrations?

It has accelerated over the past several decades as human carbon emissions have accelerated

Which is true about the recent rise in atmospheric CO2 concentrations?

It has been associated with an increase in CO2 levels and acidity in the ocean

Which of the following would NOT be expected from CO2 forcing?

\-The entire atmosphere warming from top to bottom (i.e., stratosphere and troposphere)

\-CO2 forcing would cause warming in the troposphere but cooling in the stratosphere, as the greenhouse gases trap more energy in the lower atmosphere. 

Solar output rose over the past 40 years alongside global temperature. True or False?

\-False

\-Solar output has been stable

Climate models suggest that global temperature would have remained flat if not for human forcings over the past 50 years. True or False?

\-True

\-This is true - take a closer look at the figure on slide 26 in the "Detection and attribution" Powerpoint (green color)

Climate change science has a relatively brief history, starting in the 1990s with the rise of the internet and computers

\-False

\-Based on the "Not-So-Brief History of Climate Change Science" video

When was the Greenhousse effect discovered?

\-1820s

\-Based on the "Not-So-Brief History of Climate Change Science" video

According to the NYT article “The Science of Climate Change Explained: Facts, Evidence, and Proof”, what percentage of publishing climate scientists agree that humans are causing climate change?

\-Nearly 100%

 -more than 97 percent of publishing climate scientists agree on the existence and cause of climate change

Which list describes the order in which extreme events can be most confidently linked to climate change, from most to least?

\-heat waves, heavy rainfall, hurricanes

\-Extreme heat and cold are the easiest because they are the primary effect of greenhouse warming

\-Rainfall is hard because it is a secondary effect of warming (related to changes in atmospheric circulation)

\-Hurricanes and wildfires are even harder because they are more steps removed from warming and involve more factors

In a warming climate (i.e., the bell curve shifts warmer), which can be more confidently attributed to climate change - a day that is "moderately hot" (i.e., in the top 10% of warmest days on record) or "record hot" (i.e., warmer than any previous day in history)?

\- a day that is "record hot"

 -record hot days can be more confidently attributed to climate change

\-Moderate hot days could be due to internal variabilities

The poles have larger day-to-day temperature variability than the tropics (e.g., ±10°F vs. ±1°F). If both experience the same amount of overall climate warming (e.g., +3°F), which region would you expect to have a greater increase in “extremely hot” days (e.g., what are currently the warmest 1% of days)?

\-Tropics

 -climate change has a proportionally bigger effect on areas with a small range of temperatures than areas with a large range

\-Take a closer look at slide 19 & 20 in "Event attribution" Powerpoint

The changing temperature distribution in the figure below shows that “hot” summers became twice as common from 1951-1980 to 2001-2011. Approximately what fraction of “hot” summers in 2001-2011 were related to climate change? I

\-50%

\-The red area (including the dark red) in the second figure is approximately twice as big as the red area in the first figure

Based on the same figure as in the previous question, approximately what fraction of “extremely hot” summers in 2001-2011 were related to climate change?

\-100%

\-There is no dark red area in the first figure so "extreme hot" summers in 2001-2011 in the second figure are all related to climate change

Event attribution science cannot say with 100% confidence that climate change “caused” a particular extreme weather event. True or False?

\-True

\-This is correct but it can be spoken in probablities

If a town experiences a 100-year flood, it is safe from a flood of that magnitude for another century. True or False?

\-False

\-we can talk about probabilities but cannot confidently say that a flood of that magnitude won't happen in a century

Large-scale climate patterns in a model simulation, such as the mid-latitude westerly wind systems, are written as a line of code in the model. True or False?

\-False

\-Large-scale climate patterns in a model simulation are way more complex than several lines of codes

\-NCAR supercomputer has 100 racks total

Climate models are statistical models that use past patterns and correlations to predict the future. True or False?

\-False

\-Climate models calculate the change in the likelihood of a given event in a computer simulation with and without added greenhouse gases

The average of many models typically does a better job simulating climate than any individual simulation from a single model. True or False?

\-True

\-We use lots of models with different parameterizations because the average usually does better than any individual model

Which of the following is true of global climate models?

\-Models divide the world into lots of boxes and use mathematical equations to calculate flows of energy, air, and water between them

\-Different models account for climate processes in different ways (boxes including but not limit to air, water, energy, etc)

\-Models can be designed to do both small-scale and large-scale processes

How are climate models tested?

\-By being compared to actual observations of the climate

 -Climate models are tested by being compared to actual observations and see how close between the actual observations and calculated values

Which of the following is true about climate models?

\-Complex phenomena like El Nino emerge spontaneously from the basic equations underlying the model

\-Not all processes in models can not be directly simulated

\-The average of models does a better job representing the processes than individual models

\-The smaller the grid boxes in the models, the more detailed representation of the processes we have

Sometimes past disagreements between models and data (i.e., real-world measurements) turned out to be the fault of the data. True or False?

True

How much does the scientific community expect global sea level to rise by 2100?

\-A few feet

\-Most likely a few feet by 2100

\-It will rise much more in the following centuries if we don’t phase out emissions soon

\-Slide 37 in "Models and projections" Powerpoint

According to the National Geographic article “5 Possible Futures – From the Optimistic to the Strange”, which of the storylines of socioeconomic development and carbon emissions envisioned by the Intergovernmental Panel on Climate Change does the world currently seem to be following?

\-The middle emission scenario, with 2-3°C of global warming

\-Based on the article, the middle emission scenario is what the world currently seems to be following

Because ice sheets melt so slowly, sea level rise is not likely to impact anyone in this century. True or False?

False

So-called wet bulb temperatures could reach deadly levels in the warmer parts of the world with 3°C of global warming, too hot for humans to survive. True or false?

\
True

The Economist video “See What Three Degrees of Global Warming Looks Like” suggests that major climate impacts are already occurring in some places, such as in Bangladesh where climate migrants are moving to the capital Dhaka.

True

The Economist video “See What Three Degrees of Global Warming Looks Like” points out that not everyone will be affected by climate change, for instance, wealthy cities like Paris and Berlin.

False

What does the Anthropocene refer to?

\-An epoch of geological time in which humans are the major driving force of global change

\-Refer to slide 36 in " Anthropocene" Powerpoint

Which is NOT part of the argument for the Anthropocene?

\-We have travelled to the moon and put satellites in orbit, launching us into the space age

\-There are 8 lines of arguments for the Anthropocene, including climate, new anthropogenic materials, metals and rare earth elements, sediment processes, nutrient cycles, radioactive fallout, extinctions, and biogeography

What does The Economist article "A Man-made World" suggest is the most fundamental change on planet Earth that the Anthropocene marks?

\-The rise of intelligent life that can control the planet

 - "...because of the most fundamental change in Earth history that the Anthropocene marks: the emergence of a form of intelligence that allows new ways of being to be imagined and, through co-operation and innovation, to be achieved".

What is the strongest claim of those proposing the Anthropocene (discussed in the article "A Man-made World")?

\-That it is changing the very way that the Earth system operates and behaves

\-"...the strong claim of those announcing the recent dawning of feedbacks that act upon each other. This system can behave in distinctive and counterintuitive ways, including sometimes flipping suddenly from one state to another".

We have already successfully reversed one of the “Planetary Boundaries” we crossed – degradation of the ozone layer. True or false?

\-False

\-Refer to slide 35 in "Anthropocene" Powerpoint. 

Which would cause the greatest peak warming?

\-All of these scenarios would yield similar peak values of global warming

\-Because the total amount of carbon emiited is the same, regardless of the emission rate, all of these scenarios would yield similar peak values of global warming’

\-Refer to slides 9 & 10 in "Cumulative emission" Powerpoint

Imagine that the amount of bacteria in a petri dish grows exponentially through time, doubling every day until the dish is completely covered by bacteria on day 100. On what day would the petri dish be 50% covered by bacteria?

\-Day 99

\-Keep in mind that the bacteria grow exponentially through time

\-

How rapidly would global carbon emissions need to be ramped down to zero to have a decent chance of keeping global warming below the level most governments consider dangerous?

\-A few decades

 -Refer to slide 25 in "Cumulative emissions", this needs a few decades. 

Most climate models suggest that, given current CO2 concentrations in the atmosphere and projected global emission rates, CO2 will need to be sucked out of the air to keep the world from warming to the level most governments consider dangerous (from the Economist article "What They Don't Tell You About Climate Change") True or false?

True

A large number of countries are currently investing huge amounts of money into researching how to more effectively capture carbon from the atmosphere (from the Economist article "What They Don't Tell You About Climate Change"). True or false?

\-false

\-The article did talk about the Paris agreement but did not mention that many countries are investing money into researching how to more effectively capture carbon from the atmosphere. 

What fraction of humanity’s carbon emissions have occurred in the past 30 years?

\-50%

\- half of all carbon ever emitted has been in the past 30 years

According to the film “Do the Math”, how much fossil fuel is in existing reserves in the ground compared to how much can be emitted while still keeping global temperature below the value most governments consider “dangerous”?

Five times as much

What level of global warming do most governments consider “dangerous”?

\-2°C

 -Refer to slide 26 in "Cumulative emissions"

\-2 deg C is the warming limit all nations agree on.

Approximately what fraction of global energy use is supplied by fossil fuels?

\-85%

\-This is a fact that fossil fuels supply \~85 percent of world energy

Developing countries are projected to contribute more to future increases in greenhouse gas emissions than developed countries due to large increases in population and economic growth. True or False

True

We have already burned most of the fossil fuels on the planet.

\-False

\-Taking into consideration the current rate of natural gas production and current known natural gas reserves, we have about 30 years worth of natural gas reserves left

\- We will still have gas and coal left by the time oil runs out in 2052.

Which economic sector has been most impacted by the recent rise in renewables?

\-Electricity

\-most of the new electricity generation being added now comes from renewables, especially solar

The price of solar energy has been stable for the past decade. True or False?

False

More than half of new global electricity generation added in the past decade has come from renewable energy, mostly solar and wind power.

\-True

\-Refer to slides 19 & 20 in "Energy" Powerpoint

The Netflix “Explained” episode ‘The End of Oil’ explains how the discovery of oil in Nigeria led to widespread prosperity and stability across the country for the past 50 years, which has made Nigerians skeptical of climate change. True or false?

\-False

\-Oil has led to a complex history in Nigeria, with economic gains at times but losses and war at others (the so-called "resource curse")

According to “Before the Flood”, scientists have known about global warming for over half a century. True or False?

\
true

According to “Before the Flood”, chicken is a larger source of greenhouse gas emissions than beef. True or false?

false

“Before the Flood” shows the city of Miami elevating roads and installing pumps to deal with sea level rise.

true

“Before the Flood” says that the 2015 Paris climate agreement included a global carbon tax, which will ensure that every country reduces their emissions as much as pledged.

false

 “Climate Hustle” suggests that scientists during the 1970s warned of global cooling.

true

“Climate Hustle” suggests that numerous scientists who once believed in human-caused climate change no longer do.

true

"Climate Hustle" agrees that carbon emissions are driving global warming and sea level rise at alarming rates, but it argues that we will be able to adapt to whatever changes they bring.

false

"Climate Hustle" suggests that activists blame climate change for any sort of unusual weather, whether heat waves and droughts or cold snaps and snowstorms.

true

Which is NOT part of how “Climate Hustle” characterizes atmospheric CO2?

It is currently near the highest levels it has been in Earth history

Which of the following statements does “Climate Hustle” agree with?

Earth’s climate is an incredibly complicated system to understand

Thomas Friedman says in his NYT column “The climate summit has me very energized, and very afraid” that for the first time at a UN climate summit, the adult delegates in the conference halls were the most afraid of young climate activists protesting outside in the streets.

true

Greta Thunberg’s TED talk "The disarming case to act right now on climate change" focuses on the importance of kids not skipping school and studying science so that they can start working on solutions to the climate problem when they become leaders in several decades. True or false?

false

Greta Thunberg’s TED talk argues that society is demoralized from too much focus on the climate crisis, and that the most important first step is to make people feel hopeful by giving them pep-talks full of positive ideas.

false

Katherine Hayhoe says in her article “Why hope and optimism are crucial for fighting climate change” that she is optimistic because the majority of people report frequently talking about climate change.

false

What does Myles Allen argue is best way to stop climate change in his TED talk “Fossil fuel companies know how to stop global warming. Why don’t they?”?

Dispose of CO2 by sequestering it underground

The Economist article “The climate issue” argues that while climate change is a major problem that markets have so far done little to solve, the right response is not to overturn capitalism, but rather to steer its strengths to the tasks of helping people adapt to climate change and reducing emissions through innovation. True or False?

True

Rebecca Henderson’s TED talk “To save the climate, we have to reimagine capitalism” argues that a major reason for climate change is that fossil fuel prices do not reflect their full costs to society. True or False?

True

Ted Halstead argues that the best way to deal with climate change in his TED talk “A climate solution where all sides can win” is to put a rising tax on carbon and return all of the money raised equally to every citizen. True or false?

False

What barriers to action on climate change does Ted Halstead suggest his carbon dividend plan would help overcome in his TED talk “A climate solution where all sides can win”?

\-The psychological barrier because most citizens would benefit financially

\-The partisan barrier because regulations could be reduced, which would draw Republican support

\-The geopolitical barrier because it would give other countries a reason to enact their own carbon dividend plan and cause a domino effect

Emma Marris says in "Inevitable planetary doom has been exaggerated" that Earth is now most of the way through its sixth mass extinction and 60% of species have been wiped out in the past century. True or false?

False

Which is not an example of an externality?

Not an example:

\-Redoing your kitchen with granite countertops increases your home value

Example:

\-Walking to work decreases traffic congestion in your city

\-Getting a vaccine decreases the chances that those around you will get sick

\-Second-hand smoke from you smoking can cause health issues for your roommate

The definition of externality:

\-a byproduct of economic activity that affects other parties without this being reflected in the cost

\-For B, the value of a kitchen with granite countertops is being reflected in the cost (home value), so it is not an example of externality.

Externalities can be negative or positive. True or false?

True

What does discounting refer to in the context of an economic cost-benefit analysis of climate change?

\-Valuing climate impacts less the further in the future they occur

\-In the context of climate change policymaking, they are considered very important for working out how much today's society should invest in trying to limit the impacts of climate change in the future.

Which best describes discussions on the economic discount rate to use to determine how to weigh future climate risks against the costs of present climate solutions?

\-The discount rate is debated because it depends on numerous uncertain factors and value judgements

\-The "correct" discount rate is hugely debated and affected by many factors

\-Refer to slides 24-28 in "Economics" Powerpoint. 

Which best characterizes the views of economists on climate change according to the NYT column "Building a Green Economy"?

\-There is consensus that carbon emissions should be reduced, but debate over how quickly to do this

According to the NYT column “Building a Green Economy”, what is a fee imposed on people who inflict costs on others called?

\-Pigovian tax

One country could put a price on carbon to incentivize people to move away from using fossil fuels, but this won't do much good if other countries don't also do the same. What is a mechanism that would encourage other countries to also start pricing carbon and reducing emissions mentioned in the NYT column “Building a Green Economy”?

 

A carbon tariff or border tax

The primary purpose of a carbon tax is to reduce economic growth. True or false?

\-False

\-The purpose of a carbon tax is to reflect the true cost of burning carbon

The primary objective of a tax on carbon is to set a price that reflects the full social cost of emissions. True or false?

\-True

\-This is statement is true as the new price will include the carbon tax which reflects the full social cost of emissions

All climate policies restrict fossil fuel production. True or false?

\-False

\-This statement is obviously wrong - not all climate policies restrict fossil fuel production

The U.S. has been investing a large fraction of its federal research and development budget toward improving renewable energy technologies for decades. True or false?

\-False

\-The International Renewable Energy Agency tracked some $634 billion in energy-sector subsidies in 2020, and found that around 70% were fossil fuel subsidies

\-About 20% went to renewable power generation, 6% to biofuels and just over 3% to nuclear.

Governments around the world do not only support clean energy, they also provide hundreds of billions of dollars in subsidies every year to support fossil fuel production and consumption. True or false?

\-True

\-This is true - subsidies for fossil fuel production and consumption are usually much higher than investment in renewable energy

Carbon prices to date have generally been too low to cause much reduction in emissions. True or false?

\-True

\-This is true - most of the time the carbon prices are not included in the price

There is currently a global carbon market with a worldwide price on carbon. True or false?

\-False

\-The International Monetary Fund has recommended a global average carbon price of $75 per tonne by the end of the decade

What does “leakage” refer to in the context of carbon markets?

\-When a price on carbon in one area shifts business and emissions to other areas without a carbon price

\-It means business & consumption shift to places without a carbon price

\- Refer to slide 13 in "Policy" Powerpoint

What mechanism do developed countries use in UN climate accords to encourage developing countries to reduce their emissions (as in our mock UN climate negotiation)?

\-Transferring money for adaptation and energy technology through the Green Climate Fund

\-developed countries are willing to give money for adaptation to increase the energy technology

Before the UN Paris climate agreement in 2015, how much global warming was the world on track for according to the NYT article “Yes, There’s Been Progress on Climate. No, It’s Not Nearly Enough”?

4°C

How much global warming is the world currently on track for according to the NYT article “Yes, There’s Been Progress on Climate. No, It’s Not Nearly Enough”?

3°C

The world is seeking to limit global warming to the "magic number" of 2°C because climate change will be safe at 1.9°C but becomes dangerous at 2°C. True or false?

\-False

\-The 2-degree scenario is widely seen as the global community's accepted limitation of temperature growth to avoid significant and potentially catastrophic changes to the planet

If global carbon emissions do not rapidly reverse course within the next few years, it will be too late to limit global warming to 1.5°C. True or false?

\-True

\-This is true as we are already in the late stage of what we can do to limit global warming in an accepted range. 

The concentration of carbon-14 (the radioactive isotope of carbon that decays away with a half-life of 5,000 years) in atmospheric CO2 has decreased.

Rising CO2 concentrations in the atmosphere are from fossil fuel emissions

The atmosphere is warming throughout its thickness, in the troposphere and stratosphere.

The statement is false (i.e., it is not happening and does not provide evidence for any of these)

Climate models driven only by natural factors predict that the world would not have warmed over the past century.

Global warming is attributable to rising greenhouse gas concentrations

Rising greenhouse gas levels have been the largest forcing of Earth’s energy budget over the past century.

Global warming is attributable to rising greenhouse gas concentrations