Part 2 Flashcards
(22 cards)
Thick sheets of ice advanced over North America as far south as New York as recently as:
18,000 to 22,000 years ago
Over the past 100 years or so, it appears that average global temperatures have:
Increased slightly
The ‘year without a summer’ (1816) may have been caused by:
A large volcanic eruption (Mt. Tambora)
If the earth were in a cooling trend, which processes would most likely act as a positive feedback mechanism?
Increasing snow cover (Snow-Albedo Feedback)
The Milankovitch Theory proposes that climatic changes are due to:
Changes in Earth’s orbit, tilt, and precession
During a period when the Earth’s orbital tilt is at a minimum, what would result?
Milder seasons: cooler summers, milder winters
Large volcanic eruptions with an ash veil that enters the stratosphere tend to ____ at the surface:
Decrease temperatures
It appears that, as the number of sunspots increases, the Sun’s total energy output does what?
Increases slightly
Studies reveal that during colder glacial periods, CO₂ levels ____ during warmer interglacial periods:
Were lower during glacial periods and higher during interglacial periods
What are possible consequences of global warming predicted by climate models?
Sea-level rise, more extreme weather, shrinking glaciers, changes in precipitation patterns, more heat waves
The ocean’s conveyor belt circulation is controlled by:
Differences in seawater density caused by temperature and salinity (thermohaline circulation)
Volcanoes are an important natural source of what?
Sulfur dioxide (SO₂)
If the earth were in a warming trend, which of the processes below would most likely act as a negative feedback mechanism?
Increased weathering of rocks (chemical weathering feedback)
A positive feedback mechanism:
Reinforces the initial change (amplifies warming or cooling)
It now appears that if global temperatures continue to rise, the oceans:
Will absorb more heat, but ocean circulation may slow down
It is now known that, overall, clouds:
Can either warm or cool depending on cloud type, height, and properties
The most recent warming trend experienced over the Northern Hemisphere could be the result of:
Anthropogenic greenhouse gas emissions
Everything else being equal, a gradual increase in global CO₂ would most likely bring about:
Global warming
Which of the conditions below would most likely produce warming at the Earth’s surface?
An increase in greenhouse gases
The much-studied temperature record of the past 140 years is derived from:
Land surface temperatures, sea surface temperatures, and air temperatures over oceans
The Earth has been in a warming trend for:
About 150 years, since the end of the Little Ice Age
Evidence suggests that throughout much of the Earth’s history, the global climate was:
Warmer than it is today
