Climate Change Exam 2

When was the greenhouse effect discovered?

1820s

What level of global warming do most governments consider "dangerous"?

2°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

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

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

50%

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

85%

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

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

Which would cause the greatest peak warming?

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

What does the Anthropocene refer to?

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

How are climate models tested?

By being compared to actual observations of the climate

Which of the following is true about climate models?

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

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

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

Electricity

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").

False

All climate policies restrict fossil fuel production.

False

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

False

Solar output rose over the past 40 years alongside global temperature.

False

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.

False

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.

False

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

False

The price of solar energy has been stable for the past decade.

False

The primary purpose of a carbon tax is to reduce economic growth.

False

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.

False

There is currently a global carbon market with a worldwide price on carbon.

False

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

False

We have already successfully reversed one of the "Planetary Boundaries" we crossed - degradation of the ozone layer.

False

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

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 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.

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%

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

Pigovian tax

Which is not an example of an externality?

Redoing your kitchen with granite countertops increases your home value

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 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

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

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

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

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

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

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

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

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

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

Carbon prices to date have generally been too low to cause much reduction in emissions.

True

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

True

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

Externalities can be negative or positive.

True

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

True

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

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

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

True

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

The "hockey stick" graph has been reproduced many times by independent groups of scientists (forming a "hockey team" of temperature curves).

True

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

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

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

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

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"

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

a few feet

Event attribution science cannot say with 100% confidence that climate change "caused" a particular extreme weather event.

true

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

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

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 average of many models typically does a better job simulating climate than any individual simulation from a single model.

true

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

false

Climate models are statistical models that use past patterns and correlations to predict the future.

false

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

false

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.

false

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

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