Earth's Changing Climate - Amplify

Absorb

To take in energy, like when Earth's surface takes in heat and light from the sun.

Atmosphere

The protective layer of mixed gases that surrounds a planet like Earth.

Carbon dioxide ($CO_2$)

A greenhouse gas made of one carbon atom and two oxygen atoms that traps heat by redirecting energy back toward Earth.

Change (in a system)

A condition that happens when a system becomes different over time because inputs and outputs are no longer in balance.

Claim

A proposed answer to a question about how the natural world works.

Climate

The typical weather patterns of a region observed and averaged over a long period of time, such as decades or centuries.

Climate change

Long-term shifts in global weather patterns and average temperatures caused by natural events or human actions.

Combustion

The chemical process of burning fuels like coal, oil, or gas, which releases energy along with $CO_2$ into the air.

Data

Factual measurements, observations, and numbers collected by scientists during an investigation.

Deforestation

The clearing or cutting down of forests, which leaves fewer trees to pull carbon dioxide out of the atmosphere.

Energy

The ability to make things move, warm up, or change.

Eruption

The sudden pushing out of melted rock (lava), ash, and gases from a volcano.

Evidence

Information and data from the natural world that scientists use to support or refute a claim.

Fluctuation

Short-term ups and downs or variations in data that happen within an overall pattern.

Human activities

Things people do—such as driving cars, raising farm animals, and clearing land—that affect the Earth system.

Lux

A scientific unit used to measure how bright or intense light is on a surface.

Methane ($CH_4$)

A powerful greenhouse gas made of one carbon atom and four hydrogen atoms that is released by livestock and traps heat.

Model

A picture, physical object, or computer simulation that helps us understand a complex scientific idea by making it simpler to see.

Reasoning

The scientific explanation that clearly connects evidence to a claim, explaining why the data proves the idea.

Redirect

To bounce or turn energy so that it travels along a new or different path instead of leaving.

Reflect

To bounce off an object or surface without being taken in or soaked up.

Scientific argument

A formal explanation that supports a claim using scientific evidence and logical reasoning.

Stability

A balanced state where a system stays mostly the same over time because incoming and outgoing amounts are equal.

Sulfur dioxide ($SO_2$)

A gas released by large volcanic eruptions that can reflect incoming sunlight and cause temporary global cooling.

Temperature

A measurement of how hot or cold something is, based on the average energy of its moving particles.

The Earth system

All the interconnected living and nonliving parts of our planet, including the land, water, ice, air, and living things.

Trend

The general, steady pattern of increase or decrease in a set of data over an extended time.

Volcano

A mountain or vent with an opening in Earth's crust that allows magma, ash, and gases to escape to the surface.

Global climate trend observed since $1880$

A steady, long-term pattern showing that global average temperatures are rising while ice on Earth's surface is melting.

Cause of increasing global average temperature

An increase in the total amount of energy absorbed by Earth's land and water surfaces.

Effect of changing carbon dioxide or methane levels on surface energy

Changing the amount of these gases in the air alters how much heat energy gets trapped, changing how much energy Earth's surface absorbs.

Effect on surface energy when atmospheric $CO_2$ or $CH_4$ increases

More outgoing heat energy gets redirected back downward, increasing the amount of energy absorbed by the surface.

Effect on surface energy when atmospheric $CO_2$ or $CH_4$ decreases

Less heat energy gets redirected back downward, allowing more to leave and decreasing the energy absorbed by the surface.

How a system stays stable even when energy flows in and out

The system remains stable as long as the amount of energy entering matches the amount of energy exiting.

Result of disrupting the balance of energy entering and exiting Earth

The amount of energy absorbed by the surface changes, causing Earth's overall temperature to either rise or fall.

Energy condition that causes Earth's temperature to rise

More energy enters the Earth system from the sun than exits out into space.

Energy condition that causes Earth's temperature to drop

Less energy enters the Earth system than exits out into space.

How an increase in greenhouse gases disrupts Earth's energy balance

It decreases the amount of energy leaving Earth, which leads to more energy entering than exiting.

How a decrease in greenhouse gases disrupts Earth's energy balance

It increases the amount of energy leaving Earth, which leads to less energy entering than exiting.

How greenhouse gases like $CO_2$ and $CH_4$ stop heat from leaving Earth

They absorb outgoing heat energy that would have escaped into space and redirect it back down toward the surface.

Main human activities that release carbon dioxide and methane

Burning fossil fuels for energy and transport (adding $CO_2$) and raising herds of farm animals like cattle (adding $CH_4$).

Methods to stop the increase of greenhouse gases in the atmosphere

Burning fewer fossil fuels, using clean energy, and planting trees to pull carbon dioxide out of the air.

Everyday choices individuals can make to lower greenhouse gas emissions

Walking or riding a bicycle, turning off unused electronics to save energy, and reducing food waste.

Long-term climate trend vs. short-term climate events

Human activities are driving a long-term pattern of warming over decades, while natural events like volcanic eruptions cause short-term temperature fluctuations for only a few years.