Climate Science

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?

(3288/5.67x 10-8)(1/4) = 490 K. Show work and give units for full credit.

Using the appropriate table in Lecture 8.1, assuming the RCP6.0 scenario, what is the mean estimate for the global mean sea level rise in 2081-2100? (in meters)

0.48

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)? 2.45 °C 0.45 °C 2.05 °C 1.25 °C 0.85 °C 1.65 °C

0.85 °C

If there were no climate feedbacks, how much would the Earth warm in response to a doubling of CO2?

1.2 degrees C

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 C

The actual climate sensitivity to a doubling of CO₂ (including all feedbacks) is likely between

1.5 and 4.5 degrees C

What fraction of greenhouse gas forcing is due to methane?

16%

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

If the per capita CO₂ emission of a country is 5 metric tons of carbon per year per person, and the population of the country is 78 million (that is 78,000,000), 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.)}

390

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

650,000 years

Approximately what percentage of the extra energy has this component stored? 50 100 70 90 60 40 80

90

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 radiation is incoming radiation multiplied by (1-albedo), or 3.7 Wm-2 X (1-0.332) = 2.5 Wm-2. For full credit, answers must show work and include units.

Do the following strategies qualify as adaptation, mitigation, or neither? Changing the timing of planting and harvesting crops Reforestation Increasing water use efficiency Curbing emissions of oxygen Using renewable energy Construction of more hurricane- and flood- resistant buildings

Adaptation Mitigation Adaptation Neither Mitigation Adaptation

Which reservoirs have gained carbon since pre-industrial times (assume the uncertainties are all zero)? Atmosphere Fossil fuel reserves Intermediate and Deep Sea Permafrost Ocean floor sediments Volcanoes Vegetation

Atmosphere Intermediate and Deep Sea

Order these reservoirs of water from smallest to largest. (Hint: see Lecture 8.2.) Lakes and rivers Atmosphere Polar ice caps, icebergs, glaciers Ocean Groundwater, soil moisture

Atmosphere Lakes and rivers Groundwater, soil moisture Polar ice caps, icebergs, glaciers Ocean

Rank the size of these reservoirs from lowest to highest (use pre-industrial values): Intermediate and deep sea Surface ocean Atmosphere Permafrost

Atmosphere Surface ocean Permafrost Intermediate and deep sea

Which of these changes are we least confident will happen during this century? Increased temperature Reduction in Arctic sea ice extent Increases in heat waves Melting of permafrost Changes in Atlantic hurricane frequency

Changes in Atlantic hurricane frequency

Which country is currently the largest emitter of carbon dioxide? China Russia United States India

China

Which of the following chemicals are regulated by the Montreal Protocol? Carbon dioxide Chlorofluorocarbons Methane Ozone

Chlorofluorocarbons

Which of these feedbacks affect the terrestrial radiation budget? [select all that apply] Cloud feedback Ice-albedo feedback Lapse rate feedback Water vapor feedback

Cloud feedback Lapse rate feedback Water vapor feedback

Which of the following mechanisms of energy transfer require a substance? [Select all that apply.] Electromagnetic Radiation Conduction Convection

Conduction Convection

Which of the following mechanisms of energy transfer involve a moving fluid? [Select all that apply.] Electromagnetic Radiation Conduction Convection

Convection

Which of the following mechanisms of energy transfer occur within the climate system? [Select all that apply.] Electromagnetic Radiation Convection Conduction

Electromagnetic Radiation Convection Conduction

Which of the following feedbacks are definitely positive (that is, there is no uncertainty that they are positive)? [select all that apply] Ice albedo feedback Cloud feedback Water vapor feedback Lapse rate feedback

Ice albedo feedback Water vapor feedback

Which of these proxy records can resolve annual time-scales? [Select all that apply.] Ice cores Pollen Marine sediments Tree rings Coral records

Ice cores Pollen Tree rings Coral records

Which of these are recent observed changes that support the hypothesis that the climate is warming? [Select all that apply.] Decreased volcanic activity Increased temperature over land Increase in El Niño events Increased ocean heat content Increase in urban heat island effect Increase in sea level Decreased snow cover Decreased Antarctic sea ice

Increased temperature over land Increased ocean heat content Increase in sea level Decreased snow cover

Which of these proxy records can provide climate data from hundreds of thousands of years ago (or more)? [Select all that apply.] Tree rings Marine sediments Coral records Pollen Ice cores

Marine sediments Pollen Ice cores

Which of these results in an increase in global sea level? [Select all that apply.] Melting of sea ice Rebounding of continents following retreat of the ice sheets Melting of glaciers Building of dams for flood control Increase in ocean temperature

Melting of glaciers Increase in ocean temperature

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 means that absorbed radiation equals emitted radiation. For the Earth, radiative equilibrium occurs when the emitted terrestrial (IR) radiation equals the absorbed solar radiation (sunlight).

Which of the following result in natural forcings of the climate? Select all that apply. Cloud feedbacks Solar variability CFCs Volcanic eruptions Soot from factories Land use changes

Solar variability Volcanic eruptions

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)

The concentration still increases, as long as the emission is still greater than the removal rate. Watch the bathtub video to see an illustration of this. to explain why, you should discuss sources vs sinks

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)

The emission must be less than the removal by oceans and biosphere in order for the concentration to decrease. This requires effectively a zero emission. Alternately, we could increase the carbon sinks (i.e. uptake by the biosphere) to remove carbon from the atmosphere and decrease the concentration.

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)

The high variability of daily values (weather) makes it difficult to predict more than a couple of weeks in advance, but averaging smooths out this variability, making average values easier to predict. Since climate is an average of weather, it is less variable, and thus easier to predict. Additionally, the climate responds to "external" conditions separate from the climate, such as changes in solar radiation or greenhouse gases. To the extent that we understand how these external conditions will behave in the future, we can predict the climate. also, climate is determined by energy balance, which we can predict based on expected future emissions.

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

The radiative forcing is the change in the top-of-the-atmosphere (TOA) energy budget due to a change in atmospheric composition or surface properties. That is, it is the change in terrestrial emission to space and absorption of solar radiation by the planet.

According to the appropriate table in Lecture 8.1, which of these is responsible for the most sea level rise recently (1993-2010)? Glaciers except in Greenland and Antarctica Greenland ice sheet Land water storage Antarctic ice sheet Thermal expansion

Thermal expansion

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.

Polaris is part of the constellation Ursa Minor (the Little Dipper) and is the current northern pole star. Polaris is considered a yellow supergiant and is about 2500 times more luminous than our Sun. Polaris has a temperature of approximately 6015 K. Calculate the wavelength of maximum emission of Polaris. Express your answer in units of micrometers or nanometers.

Wavelength = 2898 / 6015 = 0.4818 micrometers

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

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

all of these answers

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

alternated between warm and cold.

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

because of the long-lived GHG which are CO2 and N2O which are projected to continue to be effect the warming of the climate for the next couple of decades keyword: equilibrium

Current atmospheric CO2 concentrations are approximately:

between 400 ppm and 425 ppm

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

convection, conduction, radiation

Thus, sulfate aerosols _________________ the climate.

cool

Low clouds

cool the climate because they reflect solar radiation

Which regions are particularly susceptible to subsidence?

deltas

If the source of water to the bucket is large (the faucet is turned way up), the water level in the bucket must be high.

false

t/f A warmer climate will have no record cold days.

false

t/f If the bucket of water is in equilibrium (steady state), no water is being added to the bucket.

false

t/f Temperature increases are generally larger for daytime temperatures than for nighttime temperatures.

false

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

false

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

false

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

false

Which renewable energy source is responsible for the most (renewable) electricity generation? Geothermal Wind Hydropower Solar

hydropower

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

in the high northern latitudes.

Climate models _____________. [Select all that apply] include land and ocean components on horizontal and vertical grids are based on fundamental physical laws include all processes in the climate system will match the year-to-year variability of the observed climate are weather forecasting models run for longer periods of time

include land and ocean components on horizontal and vertical grids are based on fundamental physical laws

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) [ Select ] ["increase", "do not affect", "decrease"] the NH seasonal cycle. When Earth's closest approach to the sun (perihelion) occurs during the NH summer, the NH seasonal cycle [ Select ] ["is amplified", "is decreased", "does not change"] . Assuming NH summer occurs at perihelion, an increase in eccentricity of Earth's orbit around the sun [ Select ] ["does not affect", "decreases", "increases"] the NH seasonal cycle.

increase, amplified, increase

A positive feedback will ________ an initial warming.

increase/amplify

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 ["does not affect", "decreases", "increases"] the surface albedo, which ["cools", "warms", "does nothing to"] the climate.

increases cools

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.)

increases in CO2 concentrations cause a positive radiative forcing. reduction in sulfate emission reduce sulfuric aerosols that normally help cool, so this is a positive forcing increase in aerosols would be a negative forcing

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)? scenario spread observational uncertainty internal variability model spread

internal variability

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

internal variability

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

Which component of the climate system has stored most of the extra energy due to anthropogenic radiative forcing? Snow Vegetation Atmosphere Land surface Ocean Sea ice Volcanoes Ice sheets and glaciers

ocean

Which source of primary energy is responsible for the most energy usage currently (~2014)? Renewables Nuclear Oil Natural Gas

oil

The water vapor feedback is a [ Select ] ["positive", "uncertain", "negative"] climate feedback. As global temperatures increase, [ Select ] ["specific humidity", "relative humidity", "albedo of water vapor"] will also increase. The additional water vapor absorbs more [ Select ] ["microwaves", "radio waves", "terrestrial radiation", "solar radiation"] , decreasing the [ Select ] ["incoming terrestrial", "incoming solar", "reflected solar", "absorbed solar", "outgoing terrestrial"] radiation at the top-of-the-atmosphere. This results in a(n) [ Select ] ["increase", "stabilization", "decrease"] in surface temperature.

postive specific humidity terrestrial radiation outgoing terrestrial increase

Clouds [ Select ] ["absorb", "transmit", "reflect"] sunlight and absorb terrestrial longwave radiation. The difference between these two processes determines the cloud's net effect. Low clouds tend to have a [ Select ] ["stabilizing", "warming", "cooling"] effect, while high clouds tend to have a [ Select ] ["warming", "stabilizing", "cooling"] effect. On average, clouds [ Select ] ["warm", "stabilize", "cool"] the Earth, but cloud properties will change with global warming. The cloud feedback is unknown .

reflect absorb cooling warming cool unknown

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

respiration and photosynthesis Ocean-atmosphere gas exchange and land-atmosphere fluxes (photosynthesis, respiration and fire) are the big ones. Volcanism, weathering, and freshwater outgassing make minor contributions over century time-scales.

Which source of uncertainty is most important for the year 2200? scenario spread model spread observational uncertainty internal variability

scenario spread

Milankovitch Theory does not include changes in the shape of the Earth's orbit around the sun the Earth's tilt solar output None of these (That is, all of these change as part of Milankovitch cycles.) relationship between the timing of the seasons and Earth's orbital position

solar output

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

temperature

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

the mid 19th Century (~1850's)

Climate models require parameterizations [select all that apply] to approximate things like clouds, which are too small to modeled exactly because simulation of the climate requires ocean, land, and sea ice components because some processes require too many calculations to be modeled exactly because we do not always know the exact equation for a process because climate models are highly sensitive to initial conditions because ensembles of model simulations better reproduce the current climate

to approximate things like clouds, which are too small to modeled exactly because some processes require too many calculations to be modeled exactly because we do not always know the exact equation for a process

t/f If the amount of water in a bucket is increasing, the source of water (from the faucet) must be larger than the sink (the hole).

true

t/f Positive feedbacks increase the climate sensitivity to a doubling of CO₂.

true

t/f Temperature increases are generally larger over land than over ocean.

true

t/f The precipitation trend for the past century varies with location.

true

Emission from the Sun peaks in what wavelengths?

visible

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

The two gases most responsible for the greenhouse effect are:

water vapor and carbon dioxide