Earth & Atmospheric Science Flashcards
All 16 cards in this deck
What produced the gases that formed the Earth's early atmosphere?
Volcanic activity (volcanic emissions).
What happened to the water vapour in the Earth's early atmosphere?
The Earth cooled, so the water vapour condensed and fell as rain, forming the oceans and seas.
True or false? Carbon dioxide dissolving in the newly formed oceans increased the amount of carbon dioxide in the atmosphere.
False. Carbon dioxide dissolving in the oceans decreased it; volcanic emissions increase it.
What caused the amount of oxygen in the atmosphere to increase after the early atmosphere formed?
Plants grew and evolved, and photosynthesis occurred.
What is the chemical test for oxygen?
A glowing splint relights in oxygen.
What is the approximate composition of today's atmosphere?
About 80% nitrogen and about 20% oxygen (21%), with small amounts of other gases. Argon is the third most common gas.
Name three greenhouse gases found in the atmosphere.
Carbon dioxide, methane and water vapour.
What is the greenhouse effect?
Gases in the atmosphere absorb heat radiated from the Earth and re-radiate it back, keeping the Earth warm.
True or false? The greenhouse effect is caused by a hole in the ozone layer.
False. It is caused by gases such as carbon dioxide, methane and water vapour absorbing and re-radiating heat radiated from the Earth.
Which human activities increase the amounts of carbon dioxide and methane in the atmosphere?
Burning fossil fuels increases carbon dioxide; livestock farming increases methane.
What is the overall trend in the amount of carbon dioxide in the Earth's atmosphere over recent decades?
It increases over time (a positive trend), although it rises and falls within each year.
True or false? The correlation between rising carbon dioxide levels and rising global temperature proves that human activity is causing climate change.
False. A correlation does not prove cause, and there are uncertainties from where measurements are taken and from the accuracy of historical data.
State two possible effects of the increasing amount of carbon dioxide in the atmosphere.
Global warming (increased global temperatures) and melting of ice caps/glaciers. Other effects include rising sea levels, changing habitats and more extreme weather.
Give two ways the effects of increasing greenhouse gases may be mitigated.
Using renewable energy instead of fossil fuels, and capturing and storing carbon dioxide (or planting more trees).
Which gas did the Earth's early atmosphere contain a large amount of, but is only a small part of today's atmosphere?
Carbon dioxide ().
How much oxygen is the Earth's early atmosphere thought to have contained?
Little or no oxygen.