EASC Lesson 37: Anthropogenic Agents of Climate Change

Flashcards covering anthropogenic agents of climate change.

What is anthropogenic climate change?

Climate change caused by human activities.

What era is generally associated with anthropogenic climate change?

The Industrial Era, starting in the mid-18th century with the use of fossil fuels.

Name three human activities that substantially contribute to climate change.

Greenhouse gas emissions, aerosols injected into the lower atmosphere, and land use changes.

What is the Greenhouse Effect?

The process by which certain gases in the atmosphere trap heat, warming the Earth.

What are greenhouse gases (GHGs)?

Gases that trap heat in the atmosphere.

What three main factors determine a greenhouse gas's effect on climate change?

Abundance in the atmosphere, atmospheric lifetime, and impact on the atmosphere.

What units are used to measure greenhouse gas concentrations?

Parts per million, parts per billion, and parts per trillion.

What is Global Warming Potential (GWP)?

A measure of how much energy the emissions of 1 ton of a gas will absorb over a given period, relative to 1 ton of CO2.

Name four anthropogenic greenhouse gases.

Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases.

What is the primary greenhouse gas emitted through human activities?

Carbon dioxide (CO2).

Name three sources of anthropogenic CO2 emissions.

Power generation, transportation, and industrial sources.

Is methane a more or less powerful greenhouse gas than CO2?

More powerful, but it has a shorter atmospheric lifetime.

How do cutting and burning forests contribute to increased atmospheric CO2?

Oxidation of standing, organic carbon.

How does the tilling of forests and plowing of natural grasslands contribute to increased atmospheric CO2?

Oxidation of soil organic carbon.

What is the average atmospheric lifetime of nitrous oxide (N2O) molecules?

114 years.

Name four categories of fluorinated gases.

Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), nitrogen trifluoride (NF3), and sulfur hexafluoride (SF6).

Do fluorinated gases have natural sources?

No, they come almost entirely from human-related activities.

What are anthropogenic aerosols?

Aerosols emitted by human activities with a wide variety of compositions.

Give three examples of anthropogenic aerosols.

Carbonaceous aerosols, sulfates, and nitrates.

What are two types of carbonaceous aerosols?

Organic carbon (OC) and black carbon (BC).

What is black carbon?

The sooty black material formed by the incomplete combustion of fossil fuels and biofuels.

How does black carbon contribute to warming?

By absorbing light and heating its surroundings, influencing cloud formation, and reducing surface albedo when deposited on ice and snow.

How does sulfate aerosols impact temperatures?

Sulfate aerosols may lower earth's temperature by reflecting away solar radiation.

What are the main precursor species for nitrate aerosols?

Ammonia and nitric acid.

Give two examples of ammonia source

Excreta from domestic and wild animals, synthetic fertilizers, oceans, biomass burning, crops, human populations and pets, soils, industrial processes, and fossil fuels

How does the Amazon rainforest impacts rainfall?

About half of the rainfall in the Amazon River Basin is returned to the atmosphere through evaporation and transpiration from the leaves of trees.

What is desertification?

Land degradation in water-scarce parts of the world.

Name two causes of desertification.

Overgrazing, over-cultivation, poor irrigation practices, and deforestation.

Describe one desertification prevention method

Land and water management, protection of vegetative cover, alternative farming and industrial techniques or establishing economic opportunities outside drylands