The graph shows satellite measurements of global sea level rise since 2000 plotted relative to 1993. (sea level rise measured in mm = millimetres)
a) Draw a line of best fit through the data and write an equation for your line in the form y = mx + c, to show how sea level is rising through time.
b) What are the units of your value for mx, and c?
c) Using your equation, work out how much higher sea level will be in 50 and 100 years’ time.
Some scientists think that sea level isn’t rising with a constant rate, but is in fact accelerating.
Fitting a quadratic curve to this data gives the equation, y = 0.05x 2 + 2.6x + 21.3.
d) What are the units of the value for 0.05x2?
e) Use this equation to calculate how high sea level will be in 50 and 100 years’ time.
f) What is the difference between your answers in (c) and (e)?