### Formula

q1

quantity of resource at t1

Td

doubling time in consumption of a resource

t1

time at the start

t2

time at the end

q2

quantity of resource at t2

q1

quantity of resource at t1

Td

doubling time in consumption of a resource

t1

time at the start

t2

time at the end

q2

quantity of resource at t2

When applied to the constant growth in consumption of a resource, the total amount consumed in one doubling period equals the total amount consumed in all previous periods. Assuming two measurements of a growing quantity, q1 at time t1 and q2 at time t2, and assuming a constant growth rate, This formula can be used to calculate the start quantity q1.

Td

t1

t2

q2

q1

Precision

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