Global warming

Question 1

How much has earth warmed in the past 100 years

Answer 1

1 degree celcius

Question 2

how much might earth warm in the next 100 years

Answer 2

4 to 7 degrees F

Question 3

what causes sea level to rise?

Answer 3

thermal expansion
melting glaciers
melting of Greenland and antarctic ice caps

Question 4

how does meltwater affect rate of glacier movement

Answer 4

meltwater speeds up glacier movement as it lubricates glaciers so they slide over bedrock faster

Question 5

Define and identify feedback loops

Answer 5

action –> effect –> feedback
example; more sea ice melts, more sunlight absorbs, more earth warms, melts more sea ice, which warms earth more

Question 6

Permafrost feedback loops?

Answer 6

Permafrost melts causing half rotten plants to be exposed after being frozen for tens of thousands of years – which releases CO2 and methane into the atmosphere

Question 7

what is a positive feedback loop? example?

Answer 7

A change to a system that promotes additional change in the same direction
ex. ice caps melt, reflecting less sun, the earth warms, melts more ice caps
ex. permafrost melts, releasing CO2 and methane, earth warms, more permafrost melts

Question 8

why is predicting future climate difficult?

Answer 8

1. predicting human actions are difficult ( aka how much CO2 we will emit
2. Feedback loops make earth climate very sensitive to changes in CO2