ATS 201 Final Study Guide

What was the pre-industrial concentration in ppm (based on the figure at the top of the quiz)? Round to nearest whole number.

278

If we decrease sulfate aerosol emissions in the future,

all of these answers: we will improve air quality and decrease the occurrence of acid rain. it will lead to an increase in temperature. we will feel the full effects of anthropogenic greenhouse gases.

Throughout the ice core record (>650,000 years), temperature has mostly

alternated between warm and cold

What quantity is plotted in this figure? What are the units?

atmospheric CO2 ppm

Current atmospheric CO2 concentrations are approximately:

between 400 ppm and 425 ppm

In the Daisyworld model, which sort of feedback allowed the planet to have a reasonably stable temperature for a wide range of solar luminosities?

negative

Most terrestrial radiation emitted from Earth's surface is:

absorbed by the gases and clouds in the atmosphere

Of the solar radiation incident at the top of the atmosphere, the largest fraction is:

absorbed by the surface

You're living in the future and fly to Saturn for holiday. You need to know what kind of clothes to pack, so you decide to do some energy budget calculations. The average incoming solar radiation (Q) for Saturn is 3.7 Wm-2. Saturn's albedo is 0.332. What is the absorbed solar radiation?

absorbed solar radiation = Q(1-a) 3.7 Wm-2 (1-0.332) = 2.4716 Wm-2

How do sulfate aerosols influence radiation at the top of the atmosphere?

they increase reflected solar

How do greenhouse gases affect radiation at the top of the atmosphere?

they reduce outgoing terrestrial

Make the best match between the climate proxy method and the type of information it provides about past climate. [Note that there are extra possible answers, but no answers are used for more than one type of proxy.]

tree rings - temperature, rainfall, droughts ice cores - atmospheric CO2 and CH4 concentrations marine sediments - ocean temperature and salinity, ice sheet volume, and sea level

Temperature increases are generally larger over land than over ocean.

true

The historical temperature trend depends on the particular years that are used in the calculation.

true

The precipitation trend for the past century varies with location.

true

Emission from the Sun peaks in what wavelengths?

visible

List (yes, just list them!) two other fluxes/processes besides fossil fuel emissions that affect the atmospheric concentration of carbon dioxide.

volcanic eruptions burning/clearing land and vegetation

Thus, greenhouse gases _________________ the climate.

warm

Most of the extra energy absorbed in the Earth's climate system due to anthropogenic greeenhouse gas increases has gone into

warming the ocean

Convert a temperature change of -4.0 °C to a temperature change in °F. Round to 1 decimal place (for example, an answer of 5.37 should be input as 5.4).

-7.2

Calculate the planetary albedo (round to three digits after the decimal, for example, 0.873).

0.294

Around 2050, the likely range of temperature changes, relative to the 1986-2005 average, including all four scenarios and model uncertainty, is roughly

0.5 to 2.5˚C

Around 2100, the likely range of temperature changes, relative to the 1986-2005 average, including all four scenarios and model uncertainty, is roughly

0.5 to 5.0˚C

What is the best estimate for surface warming from 1880 to 2012 (in degrees C, to two decimal places)?

0.85

What is the best estimate for surface warming from 1880 to 2012 (in degrees C)?

0.85 ˚C

For the 2081-2100 time period, what is the difference between the land and ocean mean temperature changes for RCP4.5 (in °C)?

0.9

What is the current energy imbalance at the top of the atmosphere? Units are Wm-2, input a number only.

1

Rank the natural fluxes of carbon into the atmosphere from lowest to highest (so the most important one is last):

1 (lowest) - volcanism 2 - freshwater outgassing 3 - ocean atmospheric gas exchange 4 (highest) - total respiration and fire

In equilibrium, the Earth's surface temperature would warm by approximately how much in response to a doubling of the atmospheric carbon dioxide (CO2) concentration, relative to its pre-industrial concentration if there were no climate feedbacks?

1.2 degrees celcius

If anthropogenic emissions follow the RCP 4.5 scenario, what is the mean global surface air temperature change projected for the years 2081-2100? [In °C, to one decimal point]

1.8

What is the "greenhouse forcing" - the difference between the radiation that would be emitted to space if there were no atmosphere (but the same surface temperature), and the terrestrial radiation emitted by the planet currently? Units are Wm-2, and the number should be positive, rounded to the nearest whole number.

159

What fraction of greenhouse gas forcing is due to methane?

16%

If the per capita CO₂ emission of a country is 3 metric tons of carbon per year per person, and the population of the country is 63 million (that is 63,000,000), what is the total CO₂ emission in millions of metric tons of carbon per year of that country? {Do not include units. The value should be an integer (no numbers after the decimal point.)}

189

Calculate the effective temperature of the surface in K, assuming the surface acts like a blackbody. (Round to the nearest whole number and enter a number only).

289

What maximum global average temperature change does the Paris Agreement target (that is, try to stay under)?

2˚C above pre-industrial levels

In 1960, the CO2 concentration at Mauna Loa Observatory was ____ ppm (to within 3 ppm).

317

By what percent of its natural value has the flux of carbon into the ocean from the atmosphere (not the net flux) increased? Round to the nearest whole percent and input a number only.

33

What is the incoming solar radiation (Q) in Wm-2?

340

The figure above uses unit of PgC or PgC/yr, whereas other figures use ppm for atmospheric concentrations (and ppm/yr for trends). 2.12 PgC is approximately 1 ppm. Convert the current (as of the date of this figure) atmospheric carbon reservoir into the concentration in ppm. Round to the nearest whole number.

391

What is the longwave radiation emitted by the surface (in Wm-2)?

398

Convert the concentration in the previous question to ppm. Round to the nearest whole number.

450

Convert 9 °C to °F. Round to the nearest whole number (for example, an answer of 88.64 should be input as 89).

48

The current concentration of atmospheric CO2 is greater than it has been for at least the last

650,000 years

For the time period 2281-2300, what is the difference in global mean temperature changes between the highest and lowest RCPs (in °C)?

7.2

Approximately what percentage of the extra energy has this component stored?

90

If all of the carbon emitted so far due to fossil fuel usage had remained in the atmosphere, what would the total current CO2 atmospheric concentration be in PgC? Assume that land and ocean carbon fluxes remain at their pre-industrial values.

954

Why can we make predictions about the climate for the next century, but we can predict weather for only a couple of weeks? (~2-3 complete sentences written in your own words)

Climate is predictable because it uses many decades of data in which we are able to follow a trend/pattern showing what the climate will look like in the next century should the data continue to follow that trend. Weather can only be predicted for a couple of weeks because it is highly variable and there are many factors that can change within a short period of time.

What happens to the atmospheric concentration of CO2 if fossil fuel emissions decrease, but do not stop? Explain why. (2-4 complete sentences written in your own words)

If fossil fuel emissions were to decrease but not stop, the atmosphere concentration of CO2 would continue to increase but at a slower pace as we are still going to be emitting CO2. The concentration would also continue to cycle for thousands of years.

What must happen to fossil fuel emissions in order to decrease the atmospheric concentration of CO2? (2-3 complete sentences written in your own words)

In order to decrease the atmospheric concentration of CO2, fossil fuel emissions would have to be lowered as to allow Earth's natural processes to take CO2 out of the atmosphere. Right now we are producing more fossil fuel emissions than can be removed, increasing the atmospheric concentration.

In year 2100, which scenario or scenarios would stand at least a 95% chance of keeping the climate change below a 2°C warming? Select all that apply.

RCP 2.6

Now look at the ranges provided for each scenario (the numbers within the parentheses). These represent the 5 to 95% ranges. So there is a 5% chance that the actual temperature change would be smaller than the first number for that particular scenario, and a 5% chance the change would be larger than the second number (and thus a 95% chance of staying below this second number). Say we wanted to keep the global average temperature change in 2181-2200 below 3 °C. (Note that 2 °C is generally considered the threshold for avoiding severe climate change.) Which of the four RCPs would stand at least a 95% chance of keeping the climate change below 3 °C? (Select all RCPs for which this is true, or "None" if none of them do.)

RCP 2.6

In year 2200, which scenario or scenarios would stand at least a 95% chance of keeping the climate change below a 4°C warming? Select all that apply.

RCP 4.5 RCP 2.6

Which of these is most responsible for uncertainty in projected mean temperature in 2100?

RCP scenario spread

Define radiative equilibrium. (~1-3 complete sentences written in your own words)

Radiative equilibrium is when the emitted terrestrial radiation is equal to the absorbed solar radiation.

Define radiative forcing. (~1-3 complete sentences written in your own words)

Radiative forcing is the change in energy from terrestrial emissions to space and what is being absorbed by the planet

As it turns out, Saturn is just a bunch of hype and you decide to fly to Mercury for some quality sunbathing. The absorbed solar radiation on Mercury is 3288 Wm-2. Assume the planet is in radiative equilibrium. What is the equilibrium radiating temperature of Mercury?

Te = [Q(1−a)σ]^1/4= [3288Wm^−2/5.67x10^−8Wm^−2K^−4]^1/4=490.72 K 491 K

Why will the climate continue to warm, even if we drastically reduce anthropogenic greenhouse gas emissions to essentially zero?

There is already such a large amount of emissions in the atmosphere that even if we reduced emissions, the amount of emissions trapped would still continue to warm the planet until it is in equilibrium. There is also CO2 trapped in the oceans that will continue to be released over time.

The two gases most responsible for the greenhouse effect are:

carbon dioxide water vapor

Which of these changes are we least confident will happen during this century?

changes in atlantic hurricane frequency

Do the following strategies qualify as adaptation, mitigation, or neither?

changing the timing of planting and harvesting crops - adaptation reforestation - mitigation increasing water use efficiency - adaptation curbing emissions of oxygen - neither using renewable energy - mitigation construction of more hurricane and flood resistant buildings - adaptation

Which country is currently the largest emitter of carbon dioxide?

china

Which of the following chemicals are regulated by the Montreal Protocol?

chloroflurocarbons

List the three ways that energy moves around in the Earth system:

conduction convection radiation

Thus, sulfate aerosols _________________ the climate.

cool

A warmer climate will have no record cold days.

false

Temperature increases are generally larger for daytime temperatures than for nighttime temperatures.

false

Temperature increases are generally larger in the tropics than in high latitudes.

false

The Earth is closer to the sun in the Northern Hemisphere (NH) summer.

false

The temperature trend for the past century is the same everywhere in the US.

false

Which reservoirs have lost carbon since pre-industrial times (assume the uncertainties are all zero)?

fossil fuel reserves vegetation

Which of these proxy records can resolve annual time-scales? [Select all that apply.]

ice cores pollen coral records tree rings

Which of these proxy records can provide climate data from hundreds of thousands of years ago (or more)? [Select all that apply.]

ice cores pollen marine sediments

Projected temperature changes for the end of this (21st) century are largest

in the high northern latitudes

If the mean temperature increases, but the temperature variability (variance) does not change, the amount of record hot weather would _______ , and the amount of record cold weather would _________ .

increase decrease

How do each of these orbital parameters affect the seasonal cycle in the Northern Hemisphere (NH)? Increases in the tilt of the Earth's axis with respect to its orbit (obliquity) _______ the NH seasonal cycle. When Earth's closest approach to the sun (perihelion) occurs during the NH summer, the NH seasonal cycle _________. Assuming NH summer occurs at perihelion, an increase in eccentricity of Earth's orbit around the sun _______ the NH seasonal cycle.

increase is amplified increases

Which of these are recent observed changes that support the hypothesis that the climate is warming? [Select all that apply.]

increase in sea level increased temperature over land decreased snow cover increased ocean heat content

Considering all the time periods, the difference in temperature changes between the highest and lowest scenarios ______ with time.

increases

When all climate feedbacks (water vapor, ice-albedo, etc.) are included, the equilibrium response to a doubling of CO₂ __________ relative to the no-feedback case.

increases

The clearing of forests to make room for pastures _______ the surface albedo, which ________ the climate.

increases cools

Emission from the Earth peaks in what wavelengths?

infrared

Which category of uncertainty is most important in projecting climate over the very near term (the next decade)?

internal variability

Which of these is most responsible for uncertainty in projected mean temperature for the next 10 years?

internal variability

Which component of the climate system has stored most of the extra energy due to anthropogenic radiative forcing?

ocean

List three indicators that the climate is warming, other than temperature changes.

ocean warming sea level rise decreased snow cover

Which source of primary energy is responsible for the most energy usage currently (~2014)?

oil

The water vapor feedback is a _____ climate feedback. As global temperatures increase, _________ will also increase. The additional water vapor absorbs more _________ decreasing the __________ radiation at the top-of-the-atmosphere. This results in a(n) increase in surface temperature.

positive specific humidity terrestrial radiation outgoing terrestrial increase

Provide two examples of anthropogenic radiative forcing, one of which is a positive radiative forcing and the other of which is a negative radiative forcing. (Be sure to indicate which is positive, and which is negative.)

positive - emissions of greenhouse gases like CO2 from things like burning of fossil fuels negative - land clearance which increases albedo

clouds ______ sunlight and _______ terrestrial longwave radiation. The difference between these two processes determines the cloud's net effect. Low clouds tend to have a _________ effect, while high clouds tend to have a _________ effect. On average, clouds _________ the Earth, but cloud properties will change with global warming. The cloud feedback is ________

reflect absorb cooling warming cool unknown

Which source of uncertainty is most important for the year 2200?

scenario spread

Milankovitch Theory does not include changes in

solar output

Which of the following result in natural forcings of the climate? Select all that apply.

solar variability volcanic eruptions

The electromagnetic (EM) radiation emitted per unit area by a blackbody is determined by its:

temperature

What quantity is plotted in this figure? What are the units?

temperature change degrees C

Direct measurements of the global average temperature using thermometers have been available since about

the mid 19th century (~1850s)

______ is defined as the current state of the atmosphere and consists of short-term variations in temperature, humidity, pressure, etc. In contrast, _______ is defined as the slow varying aspects of the atmosphere-hydrosphere-land system.

weather climate