Natural climate change Flashcards
What is climate change
Any significant change in the earths climate over a long period of time
What is the quaternary period
The most … geological … period … from around 2.6 million years ago
The most recent geological time period spanning from around 2.6 million years ago
Evidence for natural climate change
-i.. c…
-t… r…
-h… s…
-p… r…
-ice cores
-tree rings
-historical sources
-pollen records
How are ice cores used as evidence for natural climate change
-ice … are made up of … of ice, … layer for each …
-scientists … into … sheets to get long … of …
-they … the … trapped in the layers of …, allowing them to tell the … each year
-ice sheets are made up of layers of ice, one layer for each year
-scientists drill into ice sheets to get long cores of ice
-they analyse the gases trapped in the layers of ice, allowing them to tell the temperature each year
How are tree rings used as evidence for natural climate change
-as a tree … it forms a new … each …
-the … the ring the warmer and … the c…
-scientists take … and count the … to find the … of the …
-as a tree grows it forms a new ring each year
-the thicker the ring the warmer and wetter the conditions
-scientists take cores and count the rings to find the age of the tree
How are historical sources use as evidence for natural climate change
-since the 18.. global … have been measured … using …
-historical … eg diaries and … can e… the record of … change further …
-since the 1850s global temps have been measured accurately using thermometers
-historical sources eg diaries and paintings can extend the record of climate change further back
How are pollen records used as evidence for natural climate change
-… from … gets … in .
. eg. At the bottom of … and peat b…
-scientists can identify and … the preserved … to show what … were … at that …
-scientists know the … that these … live in, so … pollen from … plants shows that … conditions were …
-pollen from plants gets preserved in sediment eg. At the bottom of lakes and peat bogs
-scientists can identify and date the preserved pollen to show what species were living at that time
-scientists know the conditions that these plants live in, so preserved pollen from similar plants shows that climate conditions were similar
What are the 3 main causes of natural climate change
-m… c…
-s… v…
-v… a…
-milankovitch cycles
-solar variation
-volcanic activity
The different milankovitch cycles
-s…, the … of the earths … around the … changes from a … to an … and … again around every …,000 years
-t…, the earth is … at an … as it … the sun, this tilt/a… changes over a … of …,000
-w…, the … of the earth … on a … of around …,000 years
-stretch, the path of the earths orbit around the sun changes from a circle to an ellipse and back again around every 96,000 years
-tilt, the earth is tilted at an angle as it orbits the sun, this tilt/axis changes over a cycle of 41,000
-wobble, the axis of the earth wobbles on a cycle of around 22,000 years
How do milankovitch cycles cause natural climate change
-these … affect how … away the … is from the …, and the … that the suns … hit the …, this … the amount of … radiation the earth …, the areas that receive … are …
-… changes may have caused … and i… periods when … was the … away from the … on its orbit
-these cycles affect how far away the earth is from the sun, and the angle that the suns rays hit the earth, this changes the amount of solar radiation the earth receives, the areas that receive more are warmer
-orbital changes may have caused glacial and interglacial periods when earth was the furthest away from the sun on its orbit
How does solar variation cause natural climate change
-the suns … of … isn’t constant, it … around every .. years, this is known as solar v…
-solar … is caused by …, which are … areas of the suns … that are visible as … patches, they … the suns … of e…
-periods when … output is … and there are very … sunspots may cause the earths … to become cooler
-the suns output of energy isn’t constant, it changes around every 11 years, this is known as solar variation
-solar variation is caused by sunspots, which ate cooler areas of the suns surface that are visible as dark patches, they increase the suns output of energy
-periods when solar output is reduced and there are very few sunspots may cause the earths climate to become cooler
How does volcanic activity cause natural climate change
-major … eruptions … large … of … into the …
-some of these particles … the suns … back out to … causing the earths … to …
-volcanic … may cause … term … in the …
-major volcanic eruptions eject large quantities of material into the atmosphere
-some of these particles reflect the suns rays back out to space causing the earths surface to cool
-volcanic activity may cause short term changes in the climate
