Chapter 18: Global Climate Change

What are the largest two sources of greenhouse gas emissions in the US? How can we reduce these emissions?

-Electricity production (29 percent of 2015 greenhouse gas emissions) - Electricity production generates the largest share of greenhouse gas emissions. Approximately 67 percent of our electricity comes from burning fossil fuels, mostly coal and natural gas.2 -Transportation (27 percent of 2015 greenhouse gas emissions) - Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90 percent of the fuel used for transportation is petroleum based, which includes gasoline and diesel.3

List five major trends in climate that scientists have documented so far. List five future climate trends or impact that scientists are predicting.

1) average temperatures are increasing 2) climate is changing to drier. 3) sea level is rising 4) ice is melting from mountains and polar areas Those same 4 items will continue in the future 1) some habitats will be too warm for the plants and animals who live there. 2) some agricultural areas will cease to be productive 3) some coastal areas will be flooded 4) Streams from some mountains will cease flowing in summer because there will be no ice to melt.

Carbon offsets

A carbon offset is a reduction in emissions of carbon dioxide or greenhouse gases made in order to compensate for or to offset an emission made elsewhere.

How could an increase in water vapor create either a positive or negative feedback effect?

The amount of water vapor in the atmosphere exists in direct relation to the temperature. If you increase the temperature, more water evaporates and becomes vapor, and vice versa. So when something else causes a temperature increase (such as extra CO2 from fossil fuels), more water evaporates. Then, since water vapor is a greenhouse gas, this additional water vapor causes the temperature to go up even further—a positive feedback.

Describe what a proxy indicator is, and give two examples.

A type of indirect evidence that serves as a substitute for direct measurement and sheds light on past climate. Proxy indicators are types of indirect evidence that serve as substitutes for direct measurement. They shed light on past climate.

How might a warmer climate affect agriculture?

Climate change can disrupt food availability, reduce access to food, and affect food quality. For example, projected increases in temperatures, changes in precipitation patterns, changes in extreme weather events, and reductions in water availability may all result in reduced agricultural productivity.

Radiative Forcing

Climate forcing is defined as the difference of insolation (sunlight) absorbed by the Earth and energy radiated back to space. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter of the Earth's surface.

How is a warmer climate affecting distribution of plants and animals?

Climate warming is changing the distribution of plants and animals worldwide. Recently it was shown that in the past two decades, European bird and butterfly communities have moved on average 37 and 114 kilometers to the north, respectively.

How do scientists study the ancient atmosphere?

Clues about the past climate are buried in sediments at the bottom of the oceans, locked away in coral reefs, frozen in glaciers and ice caps, and preserved in the rings of trees. Each of these natural recorders provides scientists with information about temperature, precipitation, and more.

Why is carbon dioxide considered the main greenhouse gas?

Global warming is primarily a problem of too much carbon dioxide in the atmosphere. This carbon overload is caused mainly when we burn fossil fuels like coal, oil and gas or cut down and burn forests.

Global Climate Change

Global warming refers to the recent and ongoing rise in global average temperature near Earth's surface. It is caused mostly by increasing concentrations of greenhouse gases in the atmosphere. Global warming is causing climate patterns to change

How many climate change affect marine ecosystems?

Rising sea levels. Global sea levels may rise by as much as 69cm during the next 100 years due to melting of glaciers and polar ice, and thermal expansion of warmer water. Rising water levels will have serious impacts on marine ecosystems.

What roles have international treaties played in addressing climate change? Give two specific examples.

They have set global standards, though none are fully binding. The Kyoto Protocol and Montreal Protocol are two examples of these treaties.

Describe how rising sea levels, caused by global warming, can create problems for people.

Two major mechanisms are causing sea level to rise. First, shrinking land ice, such as mountain glaciers and polar ice sheets, is releasing water into the oceans. Second, as ocean temperatures rise, the warmer water expands.

Paleoclimate

a climate prevalent at a particular time in the geological past.

How do computer programs that stimulate climate change work? Have they been effective in helping us predict climate?

a computer programs that combine what is known about weather patterns, atmospheric circulation, atmosphere-ocean interactions, and feedback mechanisms, in order to stimulate climate processes.

Greenhouse Gases

a gas that contributes to the greenhouse effect by absorbing infrared radiation, e.g., carbon dioxide and chlorofluorocarbons.

Global Warming

a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.

Fee and Dividend

a market-based mechanism for reducing the carbon emissions that help to drive anthropogenic climate change.

Intergovernmental Panel on Climate Change

a scientific and intergovernmental body under the auspices of the United Nations, set up at the request of member governments, dedicated to the task of providing the world with an objective, scientific view of climate change and its political and economic impacts.

Carbon neutrality

a term used to describe the action of organizations, businesses and individuals taking action to remove as much carbon dioxide from the atmosphere as each put in to it. The overall goal of carbon neutrality is to achieve a zero carbon footprint.

Adaptation

adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities.

Kyoto Protocol

also known as the Kyoto Accord, is an international treaty among industrialized nations that sets mandatory limits on greenhouse gas emissions. The greenhouse effect is the warming effect of the sun on greenhouse gases, such as carbon dioxide, that act to trap this heat in our atmosphere.

UN Framework Convention on Climate Change

an international environmental treaty negotiated at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in 1992. It entered into force on 21 March 1994 and today it has near-universal membership

Milankovitch Cycles

cyclical movement related to the Earth's orbit around the Sun. There are three of them: eccentricity, axial tilt, and precession.

How do greenhouse gases warm the lower atmosphere?

it is intercepted first by the atmosphere. A small part of the sun's energy is directly absorbed, particularly by certain gases such as ozone and water vapor. Some of the sun's energy is reflected back to space by clouds and the earth's surface.

What happens to solar radiation after it reaches Earth?

it is intercepted first by the atmosphere. A small part of the sun's energy is directly absorbed, particularly by certain gases such as ozone and water vapor. Some of the sun's energy is reflected back to space by clouds and the earth's surface.

Mitigation

refers to efforts to reduce or prevent emission of greenhouse gases. Mitigation can mean using new technologies and renewable energies, making older equipment more energy efficient, or changing management practices or consumer behavior.

Climate models

systems of differential equations based on the basic laws of physics, fluid motion, and chemistry. To "run" a model, scientists divide the planet into a 3-dimensional grid, apply the basic equations, and evaluate the results.

Carbon footprint

the amount of carbon dioxide and other carbon compounds emitted due to the consumption of fossil fuels by a particular person, group, etc.

Carbon capture

the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants

Greenhouse Effect

the trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

Climate

the weather conditions prevailing in an area in general or over a long period

Carbon Sequestration

transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological site